Protein Powders, Shakes, and Drinks Review
Find the Best Protein
Powders, Shakes and Drinks. 23.5% of Protein Powders and Drinks Fail CL's Tests
of Quality.
Medically reviewed and
edited by Tod Cooperman, M.D. 
Last Updated
: 11/29/2021 | Initially Posted:
12/21/2018 | Expanded: 01/12/2020Latest Update: Nutrients In Jeopardy With a Plant-Based Diet?
Table of Contents
Summary
·
Health benefits of protein powders: Extra protein
(typically about 30 grams to 50 grams per day) from a powder or drink can help
athletes build muscle, and help older people prevent or reverse age-related
loss of muscle and strength when used in conjunction with resistance-type
exercise. It may also help people with diabetes maintain blood sugar levels and
even reverse diabetes if taken as part of low calorie diet. (See What It Does).
·
What type of protein powder is best? Protein products
vary based on the source of protein (e.g., whey, casein, soy, rice, pea, egg,
hemp, and cricket). All can help build muscle, but, in general, whey is most
popular as it is a complete protein and rather quickly digested. Casein is
digested more slowly — which is why it is sometimes taken in the evening — to
counter loss of muscle at night. Vegans may be more interested in plant
sources, such soy, pea, rice, and hemp. See ConsumerTips™, Protein for more about
each type of protein.
·
What did CL's tests of protein powders find? Among the protein
products that ConsumerLab.com selected for review, 23.5% failed to
pass tests. Interestingly, the failures were not due to protein content
but to our discovering a lot more carbohydrate, sodium, or cholesterol
than listed on labels, and one product was highly contaminated with arsenic --
a toxic heavy metal (see What CL Found).
Among products that were Approved, the lowest cost to obtain an equivalent
amount (20 grams) of protein was 37 cents from a pea protein powder while it
was over $5 for some products with many additional ingredients or offering more
of a meal-replacement profile. For most products, the cost to obtain 20 grams
of protein fell within 80 cents to $1.50. See which products were CL's Top Picks based
on a combination of quality, value, and taste. You can also compare all of the
products in the Results Table.
·
How to use protein powders: Protein taken after, rather than before,
exercise may be more beneficial (See What It Does). Protein powders are typically mixed
with water or other liquids such as milk or juice, but be aware that these can
add calories (See What to Consider When Using). Also be aware
that taste of powders varies by protein type, flavorings, and the addition of
sugar or other sweeteners, and that and some powders mix more easily into
liquids than others (see the taste and mixability comments in the Results Table).
·
Protein powder safety and side effects: Protein supplements
may cause gastrointestinal discomfort in some people, and individuals with
lactose intolerance may want to avoid certain milk-based proteins. People with
kidney disease should consult with their physician before taking protein
supplements (see Concerns and Cautions).
What It Is:
To
increase protein in the diet, one can turn to meats and protein-rich dairy,
like yogurt. The downside to meats and dairy (unless reduced fat) is that they
can also provide significant amounts of saturated fat and cholesterol. Another
way to increase protein intake is with large servings of protein-rich legumes
and grains, but this increases carbohydrate and calorie intake. Unlike
nutritionbars (see Nutrition Bar Product Review),
which need to contain a good amount of carbohydrates to give them a reasonable
texture, feel and taste, protein powders and drinks do not. Consequently,
makers of protein powders and drinks have a great deal of flexibility in the
nutritional content of these products. For example, it is quite possible to
find powders and drinks with half the fat and carbohydrates of most nutrition
bars, while often offering twice the protein. Of course, the nutrition numbers
can change significantly depending on the type of liquid with which you choose
to mix the powder (see ConsumerTips™ for the nutrient content of
milks and juices). For people seeking a powder or drink as a meal replacement,
it is important to understand overall nutritional needs, as also discussed in
the ConsumerTips™ section.
Protein powders typically come in canisters or packets ready to be mixed with
water, milk, juice, or other beverage. Protein drinks often come in
ready-to-use cans or bottles. These products are marketed as dieting aids, meal
replacements, energy boosters, endurance/recovery products, and as concentrated
sources of protein -- typically for athletes seeking to build muscle and
strength.
What It Does:
Protein is necessary to build, maintain, and repair muscle. The
Academy of Nutrition and Dietetics (AND) -- formerly the American Dietetic
Association (ADA) -- currently recognizes a daily protein requirement of about
0.40 gram/pound of bodyweight for sedentary individuals, 0.55 to 0.65
gram/pound for endurance athletes and 0.65 to 0.80 gram/pound for strength
athletes. Based on a body weight of 150 lbs., this works out to about 60 grams
for sedentary individuals, 90 grams for endurance athletes, and 109 grams for
strength athletes. As you can see, a person's need for protein can more than
double depending on their level of activity. The AND also states that the daily
maximum usable amount of protein for adults is 1 gram/pound, or 150 grams for a
150 lb. person. This amount, however, should not be consumed at one time, since
the usable amount of protein for muscle synthesis from a single meal is
believed to be roughly 30 grams. Analysis of data from
the National Health and Nutrition Examination Survey (2005-2014) found that
many older adults don't get enough protein in their diets, and this is
particularly true for women. Those not getting at least 0.36 gram/pound of
bodyweight were, for men, 31% of 51-60 year-olds, 37% of 61-70 year-olds, and
42% of those over 70. For women, it was 45% of 51-60 year-olds, 48% of 61-70
year-olds, and 50% of those over 70. Non-Hispanic blacks and those who were
single, divorced, or widowed were least likely to meet protein intake
requirements. It should be noted that the analysis was industry-funded (Abbott
Nutrition) (Krok-Schoen, J Nutr Health Aging
2019). A study (not funded by industry)
among people aged 60+ years in South Florida similarly found that those with
the lowest average protein intakes were African Americans (0.29 gram/pound),
followed by European (Caucasian) Americans (0.38 gram/pound), while Hispanic
Americans had the highest protein intakes (0.44 gram/pound) (Gropper, J Nutr Geron Geriat 2019). There is
evidence that protein intake by older people may need to be about 25% to 50%
higher than the current daily recommendations in order to better stimulate
muscle creation and reduce muscle loss -- putting intake at 0.45 to 0.55 grams
per pound (Deutz, Clin Nutr 2014).
Building and maintaining muscle mass:
Combined with regular resistance exercise, protein supplementation can help
to increase muscle mass and strength gains in both younger and older adults. A review of 22 studies in both young and older individuals
found that after training two to five times a week over periods ranging from 6
to 24 weeks, subjects getting supplemental protein gained an additional 1.5
lbs. of muscle and could leg press an additional 30 lbs. compared to subjects
not getting the extra protein. The reviewed studies involved various types of
supplements -- most of which included whey protein -- given immediately before,
during, and/or after the exercise session (Cermak, Am J Clin Nutr 2012). (See ConsumerTips™ for information about the
forms of protein: whey, casein, soy, and rice.) Similarly,
a subsequent review of 49 studies found that increasing total daily protein
intake up to 0.73 grams per pound of bodyweight (109.5 grams per day for a 150
lb. adult), significantly enhanced changes in muscle strength and size during
prolonged resistance exercise training in both younger and older adults.
Consuming more than this amount of protein per day provided no additional
benefit. All sources of protein were beneficial, including protein supplements
(whey, soy, casein, pea) or whole foods (i.e. beef, yogurt, eggs) (Morton, Br J Sports Med 2017). It has
been suggested that to optimally stimulate muscle growth, it is best to divide
the daily protein intake over three meals (Padden-Jones, Curr Opin Clin Nutr Metab Care 2009).
Resistance exercise and protein supplementation can be
particularly beneficial in older adults, since aging is associated with a progressive
loss of skeletal muscle mass and strength (known medically as
sarcopenia). Sarcopenia may increase the risk of falls in older adults (Clynes, Calcif Tissue Int 2015). Protein
supplementation after resistance-type exercising has
been shown to increase muscle protein synthesis and inhibit muscle protein
breakdown, helping muscle to build during the post-exercise recovery
period. For example, a three-month study in Brazil
among older women (average age 67) who normally participated in regular
resistance exercise (about 3 days per week) found that, compared to placebo, 35
grams of a hydrolyzed whey protein powder (providing 27.1 grams of protein)
mixed in liquid consumed immediately after exercise significantly increased
lean soft tissue (muscle, tendons, etc.) (3.8% vs. 2%) and muscle strength as
measured by volume load (45.4% vs 35.4%). Women who consumed whey protein also
had a greater reduction in a cardiovascular risk measure (ratio of total
cholesterol to high density lipoprotein), which decreased 11.8% versus 2.9% in
the placebo group. There was no significant change in body fat in either group
(Fernandes, Exp Gerontol 2018). A later study by the same researchers found that taking protein
immediately before exercise also increased lean soft tissue and improved
cholesterol, but, to their surprise, only when protein was taken after exercise did
it significantly improve metabolic health (based on fasting
blood glucose and cholesterol levels) and reduce body fat (Nabuco, Nutr Metab Cardio Dis 2018).
(It may also be best to include protein supplementation as part of a meal, as
explained in the When to take section,
further below).
Applying what they learned from the earlier studies,
the same Brazilian researchers conducted a 3-month trial among 26 older women
(average age 69) with sarcopenic obesity (i.e. age-related
muscle loss in someone who is obese). The women consumed, as a drink, either 35
grams of hydrolyzed whey protein or placebo immediately following whole body
resistance training 3 times per week. Those consuming whey protein experienced
greater decreases in total fat (-3.3% vs. -0.3% for placebo) and greater
increases in muscle in their arms and legs (6% vs 2.5% for placebo) (Nabuco, Clin Nutr ESPEN 2019).
Be aware that simply eating extra protein,
without exercise, does not help build muscle or increase strength, although it
may help with maintenance. A large, 2-year
placebo-controlled study in healthy women ages 70 to 80 in Australia who did
not perform regular resistance exercise found that a daily drink providing 30
grams of whey protein did not increase or preserve muscle mass, nor improve
muscle strength, compared to placebo (Zhu, J Nutr 2015). In
fact, both the protein and placebo groups experienced a decrease in upper arm
and calf muscle mass, as well as a decrease in hand-grip strength -- although
skeletal muscle mass remained stable for both groups. Most of the women already
had adequate protein intake (averaging 76 grams daily) at the beginning of the
study -- well above recommendations for protein intake. Similarly,
a 6-month study in Boston among older men (average age 73 years) with physical
limitations found that simply adding about 45 grams of protein (from a casein
and whey mix) beyond the recommended daily intake, without any added exercise,
did not increase muscle mass or strength compared to adding an equal amount of
carbohydrates. The study found that adding a weekly testosterone injection (100
mg), with or without the extra protein, had no effect on muscle mass or
strength but was associated with a 4.4 lb. reduction in fat (Bhasin, JAMA Int Med 2018). Along the same lines, a five-month study among women in Japan
aged 65 to 80 years who were already getting adequate protein from their diet
found that consuming 22.3 grams of whey protein twice weekly after resistance
exercise significantly increased muscle mass and hand grip strength compared to
exercise alone — but consuming the same amount of whey protein without resistance
exercise resulted in little increase in muscle mass and no improvement in hand
grip strength (Mori, Geriatr Gerontol Int 2018).
A study in China among 123 older adults (average age 70), nearly
40% of whom consumed less than the recommended daily amount of protein for
older adults, found that taking 16 grams daily of whey, soy, or whey-soy blend
(1:1 ratio) protein powder while maintaining regular daily activity helped
maintain lean mass and physical performance compared to a control group in
which, over 6 months, 1% of muscle mass was lost and there were slight declines
in gait speed physical performance. The protein powders were taken as 8 gram
servings dissolved in 100 mL of water and consumed with breakfast and dinner,
and the type of protein taken did not make a difference (Li, J Acad Nutr Diet 2021).
Also, if you already consume ample protein from
your diet, extra protein won't help, even with exercise. A study of
older men who completed 12 weeks of resistance exercise training (3 sessions
per week) and consumed supplementary protein (21 grams) or a non-protein
placebo after exercise and each night before sleep found no greater improvement
in muscle strength or size with the protein supplement than with the placebo.
The lack of benefit of protein supplementation was likely due to the fact that
the men were already consuming enough protein for their moderate training:
Those receiving the placebo, for example, were naturally consuming an average
of about 93 grams of protein daily (0.53 grams per pound of body weight) (Holweda, Nutr Physio Metab 2018). Similarly, a 12-month study of 218 older people (75-96 years
of age, mostly women) with sarcopenia (muscle loss) in Finland who were already
consuming adequate protein (about 0.45 grams per pound of body weight) in their
diets found only a slight, but not statistically significant, performance benefit
from supplementing with 20 grams of protein twice daily (from a whey-enriched
protein beverage consumed between meals) versus supplementing with a
low-protein beverage (providing equal calories) or snacking between meals on
regular protein-rich foods. All participants were instructed to do light
resistance exercises at home and given 20 mcg (800 IU) of vitamin D to take
daily during the study. There were no statistically significant differences
among the groups in terms of changes in muscle mass. The protein group gained
about one pound of weight during the study while the others had little weight
change, but the difference was not statistically significant. About one-half of
those consuming the high- or low-protein beverages reported mild
gastrointestinal symptoms versus only 9% of those who snacked on regular foods
(Bjorkman, JAMDA 2019). Additionally, a study in Canada found that neither whey nor
casein supplementation (10 grams per meal, 3 times daily) led to greater
improvements in muscle quality or function than no protein supplementation in
sixty elderly men who were already ingesting amounts of protein above the
recommended daily allowance (averaging 0.61 grams per pound of body weight) and
who underwent 12 weeks of mixed power training 3-times per week. The three
groups benefitted equally from the training (Dulac, Br J Nutr 2020).
If you are confined to bed rest, whey protein
supplementation may help you retain muscle mass. This was
suggested by a study in Texas (partially funded by the dairy industry) in which
20 healthy adults (ages 60 to 80) were assigned to 7 days of bed rest. Some ate
a diet in which protein came from a mix of animal and plant sources while
others ate a similar diet in which protein from whey isolate replaced some of
the other protein. Both groups experienced a 20% reduction in knee strength,
but the whey group tended to retain more leg muscle while losing more body fat
— although differences between groups did not reach statistical significance.
After five days of rehabilitation, the whey group recovered leg strength
faster. The researchers noted that the apparent benefit of whey may relate to
its relatively high leucine content, as leucine can stimulate muscle synthesis
(Arentson-Lantz, J Gerontol Biol Sci
Med Sci 2019).
A study in Australia also suggests
that higher intakes of protein, along with adequate calcium intake from foods, may also
reduce the risk of fractures and falls in elderly adults. The study involved
7,195 men and women (average age 85) living in one of 60 long-term care
facilities. Approximately half of the facilities served their usual menu (the
control diet -- providing a total of 700 mg calcium and 58 grams of protein per
day), while the other half of the facilities served the standard diet with
additional milk, yoghurt, and cheese (providing a total of 1,152 mg of calcium
and 69 grams of protein per day). After three months, there was an 11%
lower risk of falls among residents in the facilities that served the
additional milk, yogurt and cheese, and after five months, a 33% lower
risk of all fractures, and a 46% lower risk of hip fractures, compared to
these risks in facilities that served the control diet (Juliano, BMJ 2021).
Collagen is not a preferred protein source for
building muscle. A study among 22 women 60 to 80 years of age in
Canada who performed resistance exercise showed whey protein (Whey Protein
Isolate 895 , Fonterra) to be much more effective at building muscle
than collagen protein (Gelita hydrolyzed collagen protein,
Bodybalance). The women consumed 30 grams of the designated protein mixed in a
cup of water twice daily (before breakfast and 1 to 2 hours before bed) for six
days and did resistance exercises on a specified leg on the first and third
days. Muscle synthesis (i.e., muscle creation) in the exercised leg was much
greater in the whey group than in the collagen group -- in fact there was no
significant increase in the collagen group. In the unexercised leg, there was a
small increase in muscle creation in the whey group but not in the collagen
group (Oikawa, Am J Clin Nutr 2019).
If you take collagen (perhaps for its possible modest benefit
with regard to wrinkles or osteoarthritis), don't expect the muscular benefits
of a protein powder.
Maintaining muscle and improving fat loss:
Supplementing with whey protein may improve fat loss in people who are obese
when used with dieting and exercise, but it does not seem to reduce feelings of
hunger or suppress food intake when used without diet and exercise.
A study among obese young men found that
giving extra protein during a 4-week period of dieting (40% fewer calories than
normal) and intense exercise (6 days per week) caused them
to lose more fat (2.9 lbs. more) and gain more muscle (2.4
lbs. more) than men to whom additional protein was not provided. All
participants ate similar prepared meals and consumed 3 to 4 drinks per day of a
dairy beverage that, for some, contained added whey protein isolate (about 34
extra grams per drink) but also less fat to offset the calories of the extra
protein. Although the protein-supplemented group gained more muscle, their
increase in strength was the same as that of the group receiving the lower
amount of protein - a finding that surprised the researchers (Longland, AJCN 2016).
In contrast, a study of obese men that did not involve
dieting or exercise found that drinking a 450 mL diet beverage containing 30
grams of whey protein (versus the same beverage without whey) slowed stomach
emptying but did not reduce feelings of hunger or the amount
of food eaten at a meal three hours later (Oberoi, Nutr Diabetes 2020).
Maintaining muscle during chemotherapy
In malnourished advanced cancer patients in Italy undergoing chemotherapy and
receiving nutritional counseling, 3 months of daily supplementation with 20
grams of whey protein isolate (added by patients to their water or foods)
resulted in improved body composition, muscle strength, body weight, and
reduced toxicity (-9.8%) to chemotherapy compared to a control group that
received only nutritional counseling. (Both groups also had access, as needed,
to an energy-dense liquid formula). However, the change in self-reported
quality of life during the study was not statistically different between the
two groups and supplementation actually averaged only 12 grams of whey protein isolate
per day due to incomplete compliance by patients (Cereda, Cancer Med 2019).
Diabetes, blood sugar and insulin response:
Protein supplementation appears to aid in the control of blood sugar levels
and, possibly, the treatment of diabetes.
A study among centrally obese, insulin resistant men
found that consuming 20 grams of whey protein 15 minutes before a meal, or
during the meal, significantly reduced the increase in blood sugar after the
meal compared to not consuming the whey protein or consuming the same amount of
whey protein 15 minutes after the meal (Allerton, Br J Nutr 2018).
A small, one-day study in people with type 2 diabetes found
that drinking whey protein before a high glycemic meal resulted in improved
insulin response compared to those who did not receive the protein. In the
study, 15 men and women (whose diabetes was well controlled with the
medications sulfonylurea or metformin) drank either 50 g whey protein (in 250
ml water) or plain water before a high glycemic meal. Over a three hour period
following the meal, glucose levels were 28% lower, early insulin response was
96% higher, and overall insulin response was 105% higher after ingestion of
whey protein compared to placebo (Jakubowicz, Diabetologia 2014).
Interestingly, the effect of protein on blood sugar and
insulin levels may depend, to some degree, on the type of protein. A study in
nine healthy men (average age 30) without insulin resistance
or diabetes found that, taken on an empty stomach, whey protein elicited a
greater increase in insulin levels over 3 hours than equal amounts of protein
from isolates of rice or potato, with potato having the least effect. At 1
hour, this caused a temporary dip in blood sugar with whey protein, while blood
sugar was more steady with the other two. The men consumed one of three protein
drinks (mixed with 8.5 oz. of low-sugar orange juice) that provided similar
amounts of protein (about 45.5 g) and carbohydrates (7 to 10 grams) from the
three sources. The researchers suggested that differences in the rate at which
amino acids, particularly BCAAs, are absorbed from the different protein
sources may play a role in their impact on blood sugar and insulin, and this
may occur faster with whey protein than with plant proteins (Lorinczova,
Nutrients 2021).
A longer-term study of 30 men and women with type 2 diabetes
in the U.K. found that following a very low calorie diet (that included
protein) reversed diabetes (fasting plasma glucose fell below
7 mmol/L) in 40% of patients (87% if based on those who had been diabetic for
less than four years). Participants in the study were taken off all
antidiabetic medication and, for the first 8 weeks, consumed a very low calorie
daily diet of just 3 shakes (OPTIFAST from Nestle -- which was not
involved in the study) consisting of 43% carbohydrate, 34% protein, and 19.5%
fat, and providing 624 kcal per day, as well as up to 240 grams of nonstarchy
vegetables providing up to 76 additional kcal, and at least 2 liters of
calorie-free beverages. Normal physical activity was maintained and one-to-one
weekly counseling support was provided. Over the next two weeks, shakes were
gradually replaced with solid foods and a diet providing adequate calories for
weight maintenance. The reversal of diabetes was sustained for the next 6
months during which participants continued with an individualized weight maintenance
diet and physical activity was encouraged. On average, participants lost 31
lbs. during the first 8 weeks and remained close to the lower weight for the
duration of the study (Steven, Diabetes Care 2016).
(Note: OPTIFAST in the UK differs from that in the U.S., having a higher
fat concentration and serving size.)
Dialysis:
Dialysis (hemodialysis) treatment of people with kidney failure may decrease
protein in the blood (measured in terms of serum albumin). Serum albumin levels
less than 4.0 grams/dL have been associated with increased risk of mortality in
such patients (Owen, N Engl J Med 1993).
Protein supplementation of dialysis patients who had serum albumin levels of
3.5 grams/dL or less was associated with a 69% reduction in mortality compared
to such patients not supplemented with protein. The protein was given orally as
either Novasource Renal (21.6 grams of protein per 237 mL
serving) or Liquacel (16 grams of protein per 30 mL serving) (Benner, J Renal Nutr 2018). It is not
necessary to supplement all dialysis patients with protein. A study that
followed 10,043 dialysis patients showed no difference in mortality between
patients given protein regardless of albumin status compared to patients given
protein only when albumin was low — below 3.5 grams/dL (Weiner, ASN Kidney Week 2020).
Blood flow
A study among 99 individuals in their late 60s and early 70s found that those
supplementing for 12 weeks with 50 grams of whey protein isolate versus a
placebo of 50 grams of maltodextrin (a carbohydrate) daily had a modest but
statistically significant reduction in aortic stiffness versus a slight
increase stiffness in the maltodextrin group. However, the study found no
effect on blood flow through the carotid arteries to the brain and no effect on
overall cognitive function. The study was funded by the dairy industry (which
produces whey from milk) (Lefferts, Nutrients 2020).
Quality Concerns and
Tests Performed:
Neither
the U.S. Food and Drug Administration (FDA) nor any other federal or state
agency routinely tests nutrition powders and drinks for quality prior to sale.
Some labeling discrepancies can be spotted by calculating the expected calories
in a product, based on the protein, fat and carbohydrate contents on the label
and seeing if the total calories match the calories actually listed on the
label (see ConsumerTips™). However, most problems, and
the magnitude of such problems, can be determined only with laboratory testing.
As pointed out in an article in the Journal of
Nutrition about the quality of protein supplements (Maughan, J of Nutr 2013), other potential
issues include the absence of active ingredients, inclusion of unwanted or
harmful substances, and poor manufacturing practices. The article cites
ConsumerLab.com's 2010 review in which one protein powder was found to contain
excess sugar and two were contaminated with lead -- which is always of concern
with products made from plant-based materials or containing minerals. The
article concludes that risks associated with protein powders can be reduced by
using only products that have been tested by quality assurance programs such as
ConsumerLab.com's.
Several years ago, a quality concern specific to protein products was
contamination with melamine. Melamine has been illegally used in
place of protein in some products because it is cheaper than protein but can
make poor quality or diluted material appear to be higher in protein by
elevating the total nitrogen content detected by simple protein tests. Kidney
stones, kidney failure and death were reported in 2007 and 2008 due to melamine
used in place of protein in pet foods, milk, and infant formulas. However,
ConsumerLab.com's tests of protein products in 2010 did not find melamine in
any products, and no cases of melamine contamination have been reported in
recent years. Consequently, products in the current review were not tested for
melamine.
Another way to fool tests for protein is the substitution of lower-cost amino
acids, because the standard test for protein first breaks down the protein, by
hydrolysis, into amino acids and then reports the total amount of amino acids
as being the amount of protein. However, in 2013, ConsumerLab checked 30
products for this (by doing amino acid analysis before and after the hydrolysis
step) and didn't find any discrepancies. In 2016 we checked another 31 products
and, again, found no evidence of spiking. Consequently, this extra step (which
is expensive) is no longer routinely performed in our Review.
Arsenic contamination can be a concern with products made from
rice, including protein powders made from rice. Arsenic is a toxic heavy metal
and known carcinogen that can damage organs. In 2012, FDA tests found
arsenic levels in twelve rice protein supplements (product names were not
provided) to range between 0.1 mcg and 5.7 mcg per serving (or between 4 ppb
and 152 ppb) (See the Warning for more
about this.) The cancer warning threshold of the State of California is 10 mcg
of arsenic per daily serving, meaning that if someone consumed more than one
serving of some of these products in one day, they could exceed this amount.
A study of contaminants in popular protein
powders published in 2018 indicated that the majority contained detectable
amounts of arsenic (83.5%), cadmium (73.7%),
and lead (71.4%), and 28.6% contained mercury (Clean Label Project, 2018). Plant-based
proteins tended to be contaminated with higher amounts of metals, while egg-
and milk-based (whey and casein) proteins contained the smallest amounts.
Review of the published data (which
lacked product names) by ConsumerLab, however, showed that, based on a 35 gram
serving, none of the 133 samples exceeded reasonable safety limits for arsenic
or mercury, but 10 exceeded limits for cadmium and three for lead. The average
detectable amount of cadmium per serving was only 1.6 mcg (well below the 4.1
mcg daily safe limit), but ten samples contained between 4.6 mcg and 10.7 mcg.
In ConsumerLab's experience, elevated cadmium in protein powder tends to be due
to chocolate flavoring with cocoa powder (a known source of
cadmium), not the protein ingredient itself. The average detectable
amount of lead was 0.66 mcg per 35 g serving (well below the 2.5 mcg safe limit
applied by ConsumerLab), but four samples contained between 2.7 mcg and 4.3
mcg. "Organic" products had about twice the concentration of heavy
metals as other products — an issue ConsumerLab has noted in its reviews over
the years. Twenty-one percent of samples contained more than 3 mcg per serving
of BPA (bisphenol A, which can leach from containers made of polycarbonate
plastic), the limit for dermal contact in California without
a label warning of potential reproductive harm to women. An analysis of
combined results of the same study and a smaller 2010 study of 15 protein
products by Consumer Reports concluded that the protein powders, at their
recommended servings, did not pose an increased risk to human health from heavy
metals, but this did not assess cancer risks nor the combined effect of
exposure to multiple heavy metals (Bandara, Toxicol Rep 2020).
To see which problems might exist with current protein/nutritionpowders anddrinks,
and as part of its mission to independently evaluate products that affect
health, wellness, and nutrition, ConsumerLab.com again purchased a variety of
these products (see How Products were Evaluated). The products
were first evaluated to make sure that their listed ingredients and claims were
in compliance with FDA labeling regulations. Products were then tested for the
accuracy of their label claims regarding total calories, total carbohydrates, total
sugars, total protein, total fat (including a breakout of saturated fat and
trans-fat), sodium and cholesterol. All products were tested for lead, cadmium,
and arsenic, and those containing spirulina or algae were also tested for
mercury. Products claiming to be gluten-free were tested for gluten levels.
(For details, see Testing Methods and Passing Score).
What CL Found:
Among the 17 protein products ConsumerLab.com selected and
tested, four failed to pass tests for the reasons described
below:
·
Universal Casein Pro - Vanilla Soft Serve contained 5.6 grams
of carbohydrates per one-scoop serving — 2.6 grams or 86.7% more than the
listed 3 grams.
·
PaleoThin Organic Egg White Protein — Unflavored claimed to contain
no cholesterol but had 20.4 mg per scoop. (A similar problem was found by
ConsumerLab in 2016 with another egg protein product,Jay Robb® Egg White
Protein.)
·
Orgain® Organic Protein™ - Vanilla Bean contained 325.8 mg
of sodium per serving — 145.8 mg or 81% more than the listed 180 mg. It also
contained 0.77 grams of saturated fat, although it claimed less than 0.5 grams.
·
Entomo Farms Organic Cricket Protein Powder 2050 wascontaminated
with a relatively large amount arsenic. A two tablespoon (20 gram) serving
contained 17.6 mcg of total arsenic, of which 15.6 mcg wasinorganic
arsenic — the form considered most toxic. Arsenic has been of concern in rice
protein powders, and in rice in general, but the 780 ppb concentration of
inorganic arsenic that we discovered inEntomo Farms Cricket Powder is
far greater than the highest amount reported by the FDA in rice protein
powders (range: 4 ppb to 152 ppb) or in any rice product. The state of
California requires a warning label on products exceeding 10 mcg of inorganic
arsenic per daily serving — which this product exceeds. The U.S. does not have
a limit on inorganic arsenic in foods, but a limit of 100 ppb for infant rice cereals has
been proposed by the FDA. The other cricket powder tested, from EXO, contained
only 35 ppb of arsenic, putting it far below arsenic limits. Just as rice can
accumulate arsenic from the soil in which it is grown, crickets can accumulate
arsenic from what they are fed. It is likely that the feed used byEntomo
Farms was contaminated with arsenic.
The remaining 13 products
that ConsumerLab selected for review met quality standards and were Approved.
All of the products that claimed to be gluten-free met that claim and none,
aside from one cricket powder, failed tests for heavy metals — an improvement
over past years when elevated levels of cadmium has been found in chocolate or
cocoa containing products (cadmium is a common contaminant in cocoa and chocolate) and
lead was found in a product containing brown rice bran. Through ConsumerLab.com's
voluntary Quality Certification Program,
in which products undergo the same testing, an additional nine products were
found to meet quality standards.
Choosing a protein type
The best choice of protein will depend, in part, on your individual needs and
preferences. For example, whey protein isolates are typically lower in fat,
lactose and cholesterol than whey concentrate, and most whey and casein
products are good sources of calcium. People looking for a vegan option may
prefer soy or other plant based protein such as pea or hemp, and these can be
good sources of iron. Be aware that many products contain low-calorie non-sugar
sweeteners, like stevia, but these can cause an aftertaste.
Be sure to see ConsumerTips™ for more information about
each protein source. Also see the last column of the Results Table as well as the Ingredients table which shows what else
is claimed to be in a single serving of each product.
Consider cost
Among products that were Approved for quality, ConsumerLab.com calculated the
cost to obtain an equal amount of protein (20 grams) and this is shown in
brackets in the last column in the Results Table below. This is one indication
of value. Among products that were Approved, the lowest cost to obtain an
equivalent amount (20 grams) of protein was 37 cents from a pea protein powder,NOW
Sports Pea Protein - Natural Unflavored, followed by a whey protein
isolate,MyProtein Impact Whey Isolate, at 52 cents, while it was over $5
for some products listing many additional ingredients and offering more of a
meal-replacement profile, including carbs and fats. For most protein products,
the cost to obtain 20 grams of protein ranged from around 80 cents to $1.50.
The convenience of ready-to-drink protein shakes and drinks came at a premium,
costing about two to three times as much as powdered products for the same
amount of protein.
Top Picks:
Based
on quality, value, taste and mixability, our top choices are noted below within
the context of each category:
·
Whey protein: MyProtein Impact Whey Isolate is the least
expensive whey protein among Approved products (52 cents per 20 grams of
protein) and our Top Pick for whey. Being an isolate,
it is very low in carbs (1 gram) and fats (virtually none), although, as a
result, it produces a thin drink when mixed with liquid, having a slight
powdered-milk taste. It's palatable but you might want to mix it into a liquid
providing more flavor and/or texture. If you want whey protein that includes
added flavor, our Top Picks isON [Optimum
Nutrition]Gold Standard 100% Whey - Delicious Strawberry (86 cents
per 20 grams of protein). Less expensive isEAS 100% Whey — Chocolate (57
cents per 20 grams), but, EAS is apparently discontinuing it, along with all
EAS products. Note: If you are lactose intolerant, milk-based proteins
(aside from isolates) may contain one or more grams of lactose per serving.
Amounts found are shown in the 5th column. Some products include the enzyme
lactase to help digest the lactose.
·
Casein protein: Only one casein-only product was tested,Universal
Casein Pro — Vanilla Soft Serve, and it did not pass as it contained 2.6
more grams of carbs than the 3 grams listed. However, if you are looking for a
correctly-labeled product with casein, a combination whey protein
isolate/micellar casein powder passed testing:Quest Protein Powder — Salted
Caramel Flavor. It provides 20 grams of protein for $1.31.
("Micellar" casein is just whole casein, which is absorbed more
slowly than whey or a caseinate.)
·
Soy protein: The only product we tested in this category wasVitacost
Soy Protein Isolate - Natural Chocolate Flavor. While it is a soy proteinisolate,
be aware that it provides as much sugar (from fructose) as it does protein (15
grams of each per scoop), giving it far more carbs than any other protein
powder, let alone a protein isolate. It also has a slightly gritty mouthfeel.
Its cost is reasonable at 72 cents per 20 grams of protein (half as much asGenisoy
Soy Protein Shake Chocolate Flavor tested in 2016), but it's not
a Top Pick. It contains a variety of vitamins and minerals and,
like other vegetable-based proteins, does not contain cholesterol.
·
Egg protein: Unfortunately, the only product tested that was made from
egg white protein,PaleoThin Organic Egg White Protein — Unflavored, was
Not Approved because it contained 20.4 mg of cholesterol per scoop although it
claimed none, as noted above. It has a moderately salty, egg white taste. We
ran into the same problem regarding cholesterol in 2016 withJay Robb Egg
White Protein — Unflavored, which contained 16.5 mg of cholesterol but
listed none.
·
Pea protein: NOW Sports Pea Protein - Natural Unflavored is
our Top Pick for pea protein. It provides protein at a much
lower cost than any other protein product, just 37 cents per 20 grams, although
this may be partly explained by jumbo-sized (7 pound) container in which it
came. It has a mild pea flavor with a slight bitterness — likely because it is
a pea proteinisolate. It can be consumed on its own in liquid (it mixes
easily and smoothly) but would be even better in a vegetable smoothie. Be aware
that it is relatively high in sodium (330 mg per scoop). (In 2016,Nature's
Way Alive Ultra Shake Pea Protein — Vanilla was Approved but cost much
more -- $1.21 per 20 grams of protein.Naturade Pea Protein was also
tested in 2016 but failed for containing 181 mg more sodium than listed.)
·
Hemp protein: One product in this category was
tested, Nutiva Organic Hemp Protein Powder, and it was
Approved for quality, just as it was when we tested it in 2016. It is our Top
Pick for hemp protein, providing 20 grams of protein for $1.04.
Although it is just hemp, it has a complex vegetable flavor. A nice feature of
this product, and hemp in general, is that it provides a large amount of fiber
— 8 grams per scoop, along with 3 grams of unsaturated fat (i.e. hemp oil). As
a result, only 50% of the powder is protein, but it's a worthwhile tradeoff if
you are seeking these other nutrients. It also naturally provides significant
amounts of potassium, iron, magnesium and zinc, and is made without any
sweeteners. Be aware that Nutiva has a slightly gritty
mouthfeel and quickly settles out when mixed, so it would be best as part of a
smoothie.
·
Cricket protein: EXO Pure Cricket Powder is
our Top Pick for cricket protein. We judged it superior in
quality, taste, and value to the other cricket powder tested,Entomo Farms
Cricket Protein Powder, which, as noted earlier, was found to be
contaminated with arsenic.EXO is a fine, light brown powder that
mixes well and evenly in liquid and has a mild, savory flavor, somewhat similar
to beef boullion. In contrast, and as shown in the photo below,Entomo was
a more coarse, dark brown powder with a deeper flavor (and an odor similar to
lawn fertilizer) and some crunchiness that we found less appealing. Both
naturally provide significant amounts of vitamin B-12 (which we confirmed in
testing).Entomo is more dense thanEXO, i.e., a 2-tablespoon
serving ofEntomo weighs 20 grams versus 10 grams forEXO,
consequently,Entomo provides about twice the protein per serving asEXO (13
grams vs. 6 grams) but both are relatively expensive sources of protein: $4.08
and $3.64, respectively, fromEntomo andEXO to get 20
grams of protein. Being animal-based, both also contain a small amount of
saturated fat and some cholesterol, withEntomo having about three
times as much of each asEXO per 2-tablespoon serving.
Cricket Powders:Entomo
Farms (left) andEXO (right)
·
Mixed protein: Mixed protein products are generally
more expensive than single protein products (which you can mix on your own and
save money). The lowest-cost, Approved, mixed-protein, at $1.35 per 20 grams of
protein, was Garden of Life Sport Organic Plant-Based Protein
Vanilla. It is one of our two Top Picks for this
category. It is primarily pea protein. It mixes easily, has a pleasant
vegetable flavor, and is sweetened with stevia — which some people may like and
others may not. An unsweetened, mixed protein powder that also has a nice
vegetable flavor is Amazing Grass Protein Superfood,
although is more expensive ($2.62 per 20 grams of protein). Its primary protein
is pea, followed by hemp — contributing 3 grams of fiber.
·
Special Uses: While most of the products reviewed
focus predominantly on providing protein (with at least two-thirds of their
weight being protein, as shown in the 4th column of the Results table), some
are intended to also provide energy (with higher carbs), aid in sports recovery
(with carbs and branched-chain amino acids), or to be a meal replacement (with
carbs and healthy fats). These tend to be more expensive products.
-- For recovery after intense exercise our Top Pick is: Beachbody
Performance Recover Post-Workout — Chocolate Flavored . Each scoop
($3.50) provides 20 grams of protein from a mix of whey, pea, and casein, along
with about 4 grams of branched-chain amino acids, and 10 grams of carbs. It is
sweetened primarily with beet sugar and a smaller amount of stevia.
-- For meal replacement, particularly if you are
trying to diet by avoiding carbs, GNC Lean Shake 25 is
a good option. Each bottle provides 25 grams of protein from a mixture of milk
proteins in a base of primarily water and skim milk with added vegetable oils
(providing unsaturated fats), vitamins, and minerals, and has a nice milk
chocolate flavor. It contained no detectable lactose — good news if you are
lactose intolerant. In addition, half of its 6 grams of carbohydrates are
fiber. The bottle claims that a 12-week study found that it helped people lose
nearly twice as much weight (7.6 vs. 3.9 pounds) when included as part of a
reduced-calorie (1,500 Calories/day) meal plan with exercise. However, the
actual study or a reference to its publication in a journal is not provided on
the bottle or on GNC's website -- although the website does provide a suggested
meal plan (involving one shake taken with fruit for breakfast and one shake as
a snack between lunch and dinner) and some exercise tips. ConsumerLab staff
requested a copy of the study but was informed (on 1/8/19) that it is
proprietary and not available, so we are unable to determine the significance
of the weight-loss findings or consider this product as a Top Pick.
While many products met their claims and are listed below as
"Approved," this does not necessarily mean that each provides what's
right for you. Use the information in our ConsumerTips™ section for guidance. You
can then easily compare the products using the table below — with the assurance
that ConsumerLab.com has checked these figures to be true.
Test Results by Product:
Listed
below are the test results for 26 protein/nutrition powder and drink products.
Products are grouped by main ingredient (e.g., whey, casein, soy, hemp, etc.)
and appear alphabetically within these groups. ConsumerLab.com selected 17
products. Nine other products (each indicated with a CL flask) were tested at
the request of their manufacturers/distributors through ConsumerLab.com's
voluntary Quality Certification Program and are
included for having passed testing.
Also shown are the labeled serving sizes as well as the labeled amounts per
serving of: protein; carbohydrates and sugars; total fat, saturated fat, and
trans-fat; sodium and cholesterol; and calories -- all of which were checked in
testing. Amounts of lactose found in products are listed for those who have
trouble digesting lactose. Contamination with lead, arsenic, cadmium, and
mercury above allowed limits and the accuracy of "gluten-free" claims
is also shown. The "Protein" column lists the type of protein in each
product as well as the percentage of the product that was protein (learn more
about each type of protein and how they differ in the ConsumerTips™ section). More detail about
the protein content, as well as the full list of ingredients, is available for
each product by clicking on the word "Ingredients" in the first
column. The last column compares products on price and the cost to obtain 20
grams of protein, and it identifies other nutrients and key features of
products.
Products listed as "Approved" met their ingredient claims. Those that
did not are listed as "Not Approved" with an explanation of the
problem found in red font.
|
RESULTS OF CONSUMERLAB.COM TESTING OF PROTEIN POWDERS, SHAKES,
AND DRINKS |
||||||
|
Product Name, Serving
Size, and Suggested Daily Serving on Label |
OVERALL RESULTS: |
Did Not Exceed
Conta-mination Limit for Lead, Cadmium, Arsenic and Mercury |
Nutrition or
Supplement Facts on Label per Listed Serving Size |
Cost For Daily
Suggested Serving On Label |
||
|
Protein (grams),
Source and Form |
Total |
Fats: Total/
Sat./Trans |
||||
|
|
APPROVED |
✔ |
30 |
8 / 5 |
2.5 / 1.5 / 0 |
$0.864 |
|
|
APPROVED |
✔ |
21 |
6 / 2 |
2 / 0.5 / 0 |
$2.334 |
|
|
APPROVED |
✔ |
22 |
1 / 0 |
<0.5 / <0.5 /
<0.5 |
$1.15-$1.73 |
|
|
APPROVED |
✔ |
24 |
3 / 2 |
1.5 / 1 / 0 |
$1.034 |
|
|
APPROVED |
✔ |
15 |
1 / NL |
0 / 0 / 0 |
$1.754 |
|
|
NOT |
✔ |
24 |
3 / 1 |
1 / 0.5 / 0 |
$1.464 |
|
Milk Protein Combinations (Whey/Casein/Milk): |
||||||
|
|
APPROVED |
✔ |
24 |
6 / 0 |
0 / 0 / 0 |
$1.604 |
|
|
APPROVED |
✔ |
40 |
6 / 1 |
1.5 / 1 / 0 |
$3.754 |
|
|
APPROVED |
✔ |
25 |
6 / 2 |
6 / 1.5 / 0 |
$2.504 |
|
|
APPROVED |
✔ |
30 |
5 / 1 |
3 / 1 / 0 |
$5.374 |
|
|
APPROVED |
✔ |
22 |
3 / <1 |
0 / 0 / 0 |
$1.444 |
|
|
APPROVED |
✔ |
15 |
16 / 15 |
0.5 / 0 / 0 |
$0.544 |
|
|
NOT |
✔ |
25 |
1 / 0 |
0 / 0 / 0 |
$1.504 |
|
|
APPROVED |
✔ |
24 |
1 / 0 |
2 / 0 / 0 |
$0.444 |
|
|
APPROVED |
✔ |
15 |
9 / 1 |
3 / 0 / 0 |
$0.784 |
|
|
NOT |
Found 17.6 mcg total
arsenic (15.6 mcg inorganic arsenic) per serving |
13 |
2 / 0 |
4 / 1.5 / 0 |
$2.65 |
|
|
APPROVED |
✔ |
6 |
<1 / 0 |
2.5 / 2.5 / 0 |
$1.09 |
|
|
APPROVED |
✔ |
20 |
4 / <1 |
2.5 / 0 / 0 |
$2.624 |
|
|
APPROVED |
✔ |
20 |
10 / 6 |
1 / NL / NL |
$3.504 |
|
|
APPROVED |
✔ |
17 |
17 / 7 |
2.5 / 1 / NL |
$4.33 |
|
|
APPROVED |
✔ |
16 |
16 / 7 |
3 / 0.5 / NL |
$4.33 |
|
|
APPROVED |
✔ |
20 |
8 / <1 |
1.5 / 0 / 0 |
$1.574 |
|
|
APPROVED |
✔ |
15 |
2 / 0 |
1.5 / 0 / 0 |
$1.014 |
|
|
NOT |
✔ |
21 |
15 / 0 |
4 / <0.5 / 0 |
$1.274 |
|
|
APPROVED |
✔ |
21 |
4 / 4 |
2 / 0 / NL |
$1.604 |
|
|
APPROVED |
✔ |
30 |
4 / 1 |
3 / 0 / 0 |
$1.194 |
|
|
||||||
|
Unless otherwise noted, information about the products
listed above is based on the samples purchased by ConsumerLab.com (CL) for
this Product Review. Manufacturers may change ingredients and label
information at any time, so be sure to check labels carefully when evaluating
the products you use or buy. If a product's ingredients differ from what is
listed above, it may not necessarily be of the same quality as what was
tested. |
||||||
|
Copyright ConsumerLab.com, LLC, 2018. All rights reserved.
Not to be reproduced, excerpted, or cited in any fashion without the express
written permission of ConsumerLab.com LLC. |
||||||
ConsumerTips™:
Look
out for serving sizes
Suggested serving sizes vary widely among powders and drinks, ranging from
about 10 grams to more than 90 grams per serving among powders, and from about
one cup (237 mL or 8 fluid ounces) to over two cups for drinks. Keep this in
mind when comparing the nutritional quality of products as well as cost.
Protein: Whey, casein, soy, rice, pea, hemp or bone
broth?
Four types of protein — whey, casein, soy and/or rice — are commonly found in
nutrition powders and drinks, although other plant-based protein sources, such
as pea and hemp, have become more popular. Whey and casein are both derived
from milk (the protein in milk is 80% casein and 20% whey). The pros and cons
of these protein sources are discussed below. However, keep in mind that many
products are made from a mixture of protein sources and the relative amounts of
each type are generally not well revealed.
In terms of maintaining or
building muscle mass, studies have shown, as discussed below,
that rice and pea protein can be just as effective as whey protein — although
it is critical that one is also engaged in routine resistance exercise.
Whey protein taken with meals has shown to blunt increases
in blood sugar levels (which may help people with type 2
diabetes and insulin resistance), although plant-based proteins may
less of an effect.
Whey protein
The majority of "protein" products on the market are whey-based.
Because it is milk-derived, powders and drinks made with whey are likely to
have some milk fats (about 1 - 2 grams per serving) and a small amount of
cholesterol (about 25 milligrams per serving). The USDA recommends a maximum of
300 mg of cholesterol per day based on a 2,000-calorie diet for a healthy
individual, so the cholesterol from whey protein is minimal.
Whey is a "complete" protein, meaning that it contains all the
essential amino acids and contains the highest branched chain amino acid (BCAA)
content found in nature. The branched chain amino acids valine, leucine, and
isoleucine tend to become depleted following exercise and are needed for the
maintenance of muscle tissue. Whey protein is believed to be digested faster
than casein and more completely than soy protein. Some human and animal studies
have also suggested it may boost the body's ability to fight cancer.
Popular forms of whey include the following:
·
Whey concentrates — Whey contains a large amount of water, which
is removed to create a whey concentrate. Most of the concentrate will be
protein but will also contain lactose, fat, and cholesterol naturally found in
whey. The amount of protein will depend on the level of concentration and can
vary from 25% to 80% of the weight of the concentrate. If concentrated without
the use of heat (using a "cold" process), the concentrate may still
contain the potentially beneficial immunostimulant constituents
(immunoglobulins) of whey.
·
Whey isolates — Whey protein isolates are typically lower in
lactose, fat, and cholesterol than a whey protein concentrate. If purified
without the use of heat, they may still contain the potentially beneficial
immunostimulant constituents (immunoglobulins) of whey.
·
Whey hydrolysates — Essentially this is pre-digested protein
that is assimilated into the body more quickly than other, non-hydrolyzed
types. This is well suited for use after exercise because of the increased
bioavailability of the pre-digested protein. Also, because these products are
pre-digested, less energy is needed to digest them.
·
Ion-exchange purified whey — This is the most pure of all the
whey proteins, but may have reduced immunostimulant properties due to chemical
processing.
Isolates, hydrolysates, and other purified forms are
typically more expensive than concentrates due to the additional processing.
One patented brand of whey protein isolate, Immunocal/HMS90 (Immunotec
Inc.) is permitted in Canada to be marketed as "a natural source of the
glutathione precursor cysteine for the maintenance of a strong immune system"
based on clinical research which shows taking Immunocal can
increase glutathione levels in tissue (Lands, J Appl Physiol 1999). Preliminary
research suggests that glutathione may be useful for conditions such as
psoriasis, cystic fibrosis and certain cancers. However, all whey
provides the sulfur-containing amino acid cysteine , which along with
the amino acids glycine and glutamic acid can be converted to glutathione (Tsutsumi, Austin J Nutri Food Sci
2014). This means that any whey protein isolate could be expected to
promote glutathione creation in the body. In fact, one trial found that Immunocal ,
compared to another whey product, was markedly less effective as a glutathione
precursor (Micke, Eur J Clinical Investigation
2001).
A study funded by the maker of Immunocal found that, among
sedentary, older adults (average age 71) who began a resistance exercise
program (3 times per week) and took either 20 grams of Immunocal or
20 grams of casein daily for 4 ˝ months, upper body lean muscle mass and lower
body muscle strength modestly increased in both groups, but increases in lower
body muscle strength were about 10% greater in those who took Immunocal (Karelis, J Nutr Health Aging 2015). However,
as noted below, casein is a protein that is not particularly well absorbed and
utilized, making the relative results for Immunocal less
impressive. There is not enough evidence to suggest Immunocal provides
an advantage over other whey protein isolates, and it costs significantly more
than most -- $6.60 per 20 grams versus about $1 for other isolates.
Because whey is derived from milk, whey proteins should be
avoided by anyone who is allergic to milk proteins. Similarly, whey protein
concentrates contain up to 5% lactose, which may cause gastrointestinal
disturbances in people who are lactose-intolerant. This is not an issue,
however, with whey protein isolates (Kalman, Foods 2014).
Whey protein may contain estrogens or plant-estrogens, but
amounts are extremely small and likely to be of no consequence. Although whey
comes from cow's milk which naturally contains estradiol, the estradiol is
bound to fat in the milk and there is little to no fat in whey protein powders
— so there is little estradiol in whey protein powders (Pape-Zambito, J Dairy Sci 2010).
Due to the presence of soy in cattle feed, whey protein powders may also
contain very small amounts of isoflavones (the estrogen-like compounds
typically found in soy) (Blahova, J Dairy Sci 2016).
However, amounts found in whey protein powders are minute: An analysis of a
whey protein supplement containing 80% whey protein concentrate found that it
contained less than one milligram each of the isoflavones
daidzein and genistein per 26.3 gram serving (Haun,Sci Rep 2018). In addition, because there
is some concern about the accuracy of methods used to detect isoflavones in
milk products, some researchers suggest that amounts may be even lower than
estimated.
Casein
The other milk protein, casein, is also a "complete protein" and is
extremely high in glutamine -- the predominant amino acid in muscles and throughout
the body. However, casein has a lower biological value (BV) than whey, meaning
that a lower percentage of protein is absorbed and utilized out of the total
protein consumed. Casein is larger than whey, and is not as bioavailable. Some
studies have shown casein to lead to superior gains in strength over whey --
most likely due to the slower absorption of casein, providing a release of
amino acids over a longer period of time.
For athletes looking to maintain lean muscle tissue, it is sometimes recommended
that casein be taken before bed because the slow absorption will supply the
body with protein through the night when the body enters a catabolic state
(breakdown of protein tissue for energy). However, a small
study among healthy, active young men who participated in a resistance training
program 4 days per week found that, after three months, average increases in
muscle strength and lean mass were similar whether casein (35 grams) was
consumed at bedtime or earlier in the day (at least six hours before bedtime).
Both groups also consumed 25 grams of whey protein immediately after resistance
training on exercise days. Increases in muscle strength, lean mass (which
increased by an average of about 5 pounds) and self-reported delayed-onset
muscle soreness (DOMS) were similar in both groups (Joy, J Int Soc Sports Nutr 2018).
Popular forms of casein are micellar casein (the
natural, un-denatured form of casein found in milk) which is more slowly
absorbed, and caseinates which are formed by chemically treating casein are
more readily absorbed. A common caseinate is calcium caseinate -- which is also
good source of calcium. As casein is the main
protein in milk (and even more so in Greek yogurt due to
the removal of whey) and, as noted by the National Cancer Institute,
"A diet high in dairy foods and calcium may cause a small increase in the
risk of prostate cancer," there is some concern that casein
protein may increase the risk of prostate cancer. Adding to this concern, a
laboratory study showed that casein protein promoted the growth of certain
prostate cancer cells (but not breast cancer cells) (Park, World J Mens Health 2014) and an
observational study of 500,000 men (average age 52) from ten European countries
found a 17% increased risk of prostate cancer among those who consumed the most
yogurt (median intake 57 grams/day) compared to those who consumed the least
(median intake 15 grams/day), while there was no increased risk of prostate
cancer from milk, milk beverages or cheeses in general (Allen, Br J Cancer 2008). However, other
components of dairy, such as fat content, may play a role, particularly once a
person has prostate cancer: A large study among men in the U.S. with localized
prostate cancer found that those with the highest versus the lowest intakes
of whole milk had twice the risk of progression to lethal
prostate cancer, while the opposite was true for those with the highest versus
lowest intakes of low-fat dairy (Pettersson, Cancer Epidemiol Biomarkers Prev 2012).
At this point it isn't possible to know if casein protein itself increases the
risk of prostate cancer in men but it would seem best to use it in moderation.
There is preliminary clinical evidence that peptides in a
particular casein hydrolysate (alpha-s1 casein hydrolysate, or ACH), may have
a calming effect, possibly by acting on GABA receptors (the same
receptors targeted by benzodiazepine drugs such as Valium and Xanax) (Messaoudi, Eur J Nutr 2005; Kim, Eur J Clin Nutr 2007). A placebo-controlled study among 43 men and women (average
age 49) in Korea who had mild to moderate difficulty sleeping found
that a supplement containing 300 mg of ACH (sold as Lactium,
Ingredia) taken one hour before bedtime for one month modestly improved some
subjective (self-reported) measures of sleep but not significantly more than
placebo. It also failed to show statistically significant improvements in
objective measurements of brain waves and sleep phases, such as REM sleep,
heart rate, breathing and muscle movements. There were no significant
improvements in self-reported sleep discomfort, daytime functioning or symptoms
of anxiety and depression compared to placebo (Kim, Nutrients 2019). Lactium is
an ingredient in Life Extension's Bioactive Milk Peptides supplement,
although this product contains half (150 mg) the amount of Lactium per
suggested daily serving as used in the study above.
Soy
Soy protein is acceptable to vegetarians and vegans and
does not contain much fat or cholesterol, particularly if a soy
"isolate" is used. It has long been considered the most "heart
healthy" source of protein and, in 1999, the FDA authorized the health
claim that eating 25 grams of soy protein a day, in addition to eating a low-fat,
low-cholesterol diet, can reduce your risk of heart disease. However, in
October 2017, the FDA proposedrevoking this
health claim because studies since 1999 have presented
inconsistent findings on the relationship between soy protein and heart
disease, such as whether or not it can lower LDL ("bad") cholesterol.
The FDA may allow industry to continue to use a heart health claim so long as it
"...explains the limited evidence linking consumption of soy protein with
heart disease risk reduction." Soy protein is considered a complete
protein, equivalent to human protein, although it contains little of the
sulfur-containing amino acid methionine. This deficiency in methionine is not a
problem in normal nutrition for adults and children. For newborns, however,
modest supplementation of soy-based formulas with methionine may be beneficial
(Young, J Am Diet Assoc 1991).
Soy protein contains soy isoflavones that have weak
estrogen-like effects. However, the concentration of isoflavones in soy protein
products is much lower than that in soy flour (which contains about 200 mg of
aglycone isoflavones per 100 grams of flour) and the amount varies depending on
how the soy protein was produced. For example, 100 grams of soy protein
concentrate contains only 12 mg of isoflavones if the concentrate was produced
by alcohol extraction but about 100 mg if produced by water extraction.
(See Product Review of Soy and Red
Clover Isoflavones for more information about isoflavones).
Analysis of a 39-gram-serving of a supplement containing 80% soy protein
concentrate (ALPHA 5812, Solae) showed that it contained 14 mg and 18 mg,
respectively, of the isoflavones daidzein and genistein, although consuming two
servings daily for three months had no effect on blood levels
of estradiol in healthy college-aged men (Haun,Sci Rep 2018).
Anyone with thyroid disease or a predisposition to thyroid dysfunction should
limit his or her intake of soy-based protein food, due to its potential to
affect hormone balance and inhibit the absorption of thyroid hormone medication
(Messina, Thyroid 2006). The isoflavones in soy can also affect thyroid hormone
levels in people without thyroid disease. A study in adults with normal thyroid
function that found consuming 15 grams of soy protein containing approximately
33 mg of aglycone soy isoflavones daily (as estimated based on a daily dose of
66 mg total isoflavones) increased levels of rT3 (reverse tri-iodothyronine)
and TSH (thyroid stimulating hormone), and decreased levels of fT4 (free
thyroxine) after three months of supplementation. However, levels returned to
normal after six months of supplementation (Sathyapalan, Front Endocrinol 2018).
(For amounts of isoflavones in soy protein and other soy products see the Soy Isoflavones Review).
While soy allergies are rare, those allergic to soybeans should also avoid soy
protein.
The effects of soy intake on the risk of prostate cancer
is not clear-cut. Higher intakes of soy and soy foods (such as in Asian
countries) have been associated with a lower risk of prostate cancer, but a
protective effect has not been established — and there is some evidence higher
intakes of soy isoflavones may increase the risk ofadvanced prostate
cancer. In one study, researchers in the U.S. gave soy to men who were at high
risk for recurrence of prostate cancer after having radical prostatectomy to
remove prostate cancer. The men consumed a daily drink containing about 20
grams of soy protein isolate. Although there were no apparent adverse events
related to the supplementation, there was also no statistical difference after
two years in recurrence of prostate cancer between men taking the soy and those
getting a placebo (about 28% of the men had cancer recur, judged by PSA
levels). It is conceivable, the researchers noted, that soy is protective
against prostate cancer when consumption begins early in life but not later
when prostate cancer is already present (Bosland, JAMA 2013). A
study that followed over 76,000 men in the U.S. for an average of 11 ˝ years
found no association between soy isoflavone intake and total prostate cancer
risk (all types and stages combined), but found that those with the highest
dietary intake of soy isoflavones (0.75 mg to 2.03 mg total soy isoflavones per
day) had a 91% increased risk ofadvanced prostate cancer compared
to those with the lowest intake (0 mg to 0.17 mg total soy isoflavones per day)
(Reger, Int J Cancer 2018).
Rice
While much of rice seed is carbohydrate, it also contains protein, which can be
separated out enzymatically. An analysis of a protein isolate (Oryzatein-90,
Axiom Foods) from organic whole-grain rice showed that while it contained all
of the essential amino acids, whey protein isolate contains 39% more essential
amino acids and 33% more branched-chain amino acids (Kalman, Foods 2014). Nevertheless, giving
healthy young men 48 grams of either rice protein isolate (Oryzatein-90) or
whey protein isolate 3 days per week immediately after resistance training for
two months resulted in similar increases in lean muscle mass and strength (Joy, Nutr J 2013). Rice protein is considered
to be hypoallergenic and is believed to be well absorbed. (In 2007, some rice
protein concentrates from China that were used in pet foods were found to be
adulterated with melamine.)
Pea
Pea protein, like whey and casein, is a complete protein and rich in essential
branched chain amino acids (BCAAs). A small clinical study in which intake
of pea protein isolate was compared to casein protein concluded that pea
protein isolate is a "high quality" protein that meets all amino acid
requirements and was equivalent to casein in terms of overall protein quality,
although it did find that certain BCAAs (leucine and valine) and the amino
acids lysine and phenylalanine are somewhat less digestible from pea protein
isolate than from casein and that the estimated proportion of amino acids from
pea protein that are eventually converted into proteins and used by the body
was somewhat lower with pea than casein protein (Guillin,
Am J Clin Nutr 2021).
A placebo-controlled study comparing a pea protein isolate to whey protein,
found, interestingly, that all the groups experienced nearly equivalent
increases in strength and muscle thickness. However, among men who were weakest
at the beginning of the study, the increase in muscle thickness was
significantly greater for those getting the pea protein compared to the
placebo, whereas there was no statistical difference between the whey pea or
whey and placebo (Babault, J Int Soc Sports Nutr 2015). The
12-week study involved healthy young men. They underwent strength training
three times a week. Each morning and immediately after workouts (or in the
afternoon when there was no workout), they consumed a flavored beverage made
with cold water and a powder containing 25 grams of one of the proteins or
placebo. The pea protein used was NUTRALYS from Roquette (France) which
financed the study. A small study among
exercise-trained men and women (average age 38) who participated in
high-intensity functional training four days per week for two months found
similar increases in muscle strength with twice-daily supplementation with
either pea or whey protein. However, as there was no placebo or control it is
impossible to conclude that either protein was beneficial. There were no
changes in body composition (fat mass or muscle thickness) in either group. On
exercise days, the protein powders (both purchased from True
Nutrition ) were consumed within one hour before exercise and, again,
within and one hour after exercise. On non-exercise days it was consumed once
in the morning and once in the evening, between meals (Banaszek, Sports 2019).
It is interesting to note that neither of these two studies prove an overall
benefit from supplementing with protein, but do demonstrate a benefit from
strength training.
Egg
Egg protein powder is usually derived from the egg white (albumen) portion of
the egg. It is a complete protein. Although sometimes promoted for its very
high biological value (the percentage of protein absorbed and utilized), this
is true only at lower levels of intake (about 14 grams daily) (Srikantia, FAO 1981).
There is a lack of clinical studies comparing egg white protein supplementation
with other types of protein. A small, 8-week study in female athletes (ages 18
to 22) who took 15 grams of egg white protein drink daily before exercise found
that it did not significantly increase muscle strength more than a drink
containing only carbohydrates (17.5 grams of maltodextrin) (Hida, Nutrients 2012).
Hemp
Hemp protein is derived from the industrial variety ofCannabis sativa L. which
does not have the psychoactive properties associated with marijuana (Rodriguez-Leyva, Nutr Metab 2010). Like egg
white, one of the main proteins in hemp is albumen, which is rich in protein
and contains all of the essential amino acids, including branched chain amino
acids (BCAAs). On a percentage basis, it contains lower amounts of BCAAs than
whey or soy protein, but more than rice or egg white protein. It is exceptionally
high in arginine, containing higher amounts than any of the protein sources
listed above (Callaway, Euphytica 2004).
Although there appears to be little published research on the use of hemp
protein for muscle building or sports recovery, or comparing its effects with
those of other sources of protein, there is some research underway (ClinicalTrials.gov 2016).
Bone broth
Bone broth protein
supplements (sold in capsules or as powder) consist of dehydrated broth
(typically from chicken bones which have been boiled or simmered). Chicken
bones contain all of the essential amino acids, including branched chain amino
acids (Dong, Food Chem 2014)
and chicken breast bone mainly consists of the amino acids glycine, proline and
hydroxyproline and also contains both type I and type II collagen (Losso, J Food Biochem 2013).
However, there is little information about the amino acid profile of chicken bonebroth —
which would vary based on how the broth was made, how long the bones were
simmered, which bones were used, etc., and there do not appear to be any bone
broth supplements which list their amino acid or collagen profile on the label.
Bone broths are sometimes promoted to help reduce wrinkles and joint pain,
likely based on the fact that collagen may account for a significant percentage
of the protein in bone broths. However, there do not appear to be any published
clinical studies on the effects of bone broth protein supplementation. One
small laboratory study (frequently cited as evidence of the immune
"boosting" benefits of bone broth protein) found that traditional
chicken soup (including vegetables) inhibited the movement of neutrophils (a
type of white blood cell). This movement is normally part of the
immune-system's inflammatory response, suggesting not an immune
"boosting" effect but a possible anti-inflammatory effect (Bo, Chest 2000). There is some evidence that
chicken bone broth can be contaminated with significant amounts of lead (7 mcg
per liter [about 4 cups] in broth made from "organic" chicken),
likely due to the fact that lead accumulates in bones (Monro, Med Hypotheses 2013). (Interestingly,
this study found only 1/3 as much lead in broth made with just chicken
"meat," but 35%more lead in broth made with just chicken
cartilage and skin.) (See the Bone Broth Review for
more information and tests of popular bone broths.)
Cricket
There is growing interest in crickets and other insects as more environmentally-friendly
animal sources of protein than whey or casein (as these are from cows, which
produce large amounts of methane). Cricket powder (made from washed, dried, and
ground crickets) is about 60% protein and is rich in vitamin B-12 -- easily
providing close to, or more than, the daily requirement in a single serving.
About 20% to 25% of cricket powder is fat (of which some is saturated fat, as
with other animal-based proteins), with a small amount of carbohydrate (mainly
fiber) but no sugar. A current downside to cricket powders is their relatively
high cost. As shown in this Review, cricket powders vary in color and taste and
some may be contaminated with heavy metals -- most likely depending on what
they have been fed. A safety review of crickets as food by the (European Food Safety Authority in
2018) noted the "bioaccumulation of heavy metals,"
particularly "cadmium, arsenic, lead, and tin" as a safety risk of
"considerable" concern. Additional concerns were high total aerobic
bacterial counts; survival of spore-forming bacteria following thermal
processing; and allergenicity (people who are allergic to other insects or
shellfish may react to crickets). (Note: Bacteria and mold were not tested by
ConsumerLab in this Review as they are not a common problem in other protein
powders.) Other hazards like parasites, fungi, viruses, prions, antimicrobial
resistance and toxins were ranked as low risk.
Using protein powders and drinks as meal
replacements:
The United States Department of Agriculture (USDA) recommends (effective July
26, 2016) that most adults who perform light to moderate activity get roughly
2,000 to 3,000 calories per day from a varied diet in which approximately 55%
or fewer calories come from carbohydrates, at least 10% come from protein (meat
and vegetable proteins), and about 35% come from fats — with less than 10% of
calories coming specifically from saturated fat. Healthcare professionals tend
to suggest a somewhat higher percentage of calories from protein (15% to 20%)
and a lower percentage from carbohydrates, although recommendations vary.
Nutrition powders and drinks can help provide some of these nutrients but they
are not recommended as a total substitute for food, as they lack some of the
vitamins, minerals, fiber and phytonutrients found in whole foods and sometimes
fall short on fat and carbohydrates.
Serving sizes of powders are typically 30 to 45 grams (about the same as that for
a nutrition bar, after taking into account the bar's moisture content),
although recommended serving sizes vary widely among the powders (from as
little as 15 grams to more than 90 grams). As an example, in a 45-gram serving
of a high-protein powdered mix, you could expect about 10 grams of carbohydrate
(of which sugar may account for two-thirds, unless a non-nutritive sweetener is
used), 30 grams of protein, and 2 grams of fat (a third of which is saturated).
The other few grams of weight come mostly from moisture. This powder would
provide 178 calories, with approximately 23% from carbohydrates, 67% from
protein and 10% from fat. As you can see, powders can be a great source of
protein, but can leave you short on carbohydrates and fat, if mixed with water.
A typical serving of a ready-to-use nutrition drink is about 315 mL (one and
one-third cups). Nutrients in a drink can be similar to that for a powder, but
typically have slightly less protein and slightly more carbohydrate and fat.
Ingredients you may neither expect nor want:
Some products contain ingredients that you may not expect, such as added
vitamins, minerals, herbs or other special added ingredients. Recommended
Tolerable Upper Intake Levels (ULs) have been established for many vitamins and
minerals, so it is advisable to keep track of the amounts that you may be
ingesting from the powders and drinks as well as from other foods and
supplements (see ConsumerTips™ in the Multivitamin/Multimineral Product
Review for Recommended Dietary Allowances (RDAs) and ULs or see
the summary at www.ConsumerLab.com/RDAs).
You should also be aware that products, particularly those promoted for
"energy," might include caffeine-containing ingredients, such as
coffee extract, guarana, mate, or cocoa. Be aware that caffeine can enhance the
action and increase the side effects of other stimulants. Many powders and
drinks are also fortified with an array of vitamins and minerals.
Powders and drinks may also contain an array of
sweeteners. Some are sugar-based such as sugar, fructose, honey, lactose,
maltose, and fruit juices. (For those with trouble digesting lactose, we have
shown the amount of lactose found in a serving of each product in the 5th
column of the Results table, above -- although most products had little to
none). Some have reduced calories, such as the sugar alcohols lactitol,
maltitol, mannitol, sorbitol and xylitol. And some have no calories, such as
saccharin, aspartame, acesulfame-K, and sucralose. Be aware that some products
now have a "net carb" calculation on their labels. In this
calculation, the manufacturer deducts the weight of any carbohydrate (including
sugars) that supposedly does not raise insulin levels, although it may still
contribute calories. The FDA has not approved this practice. Because of all the
possible ingredients, nutritional products should be carefully evaluated before
being used by children, pregnant or nursing women, or others with dietary
restrictions, such as people with diabetes or hypoglycemia. Make sure
things add up:
To make sure that the calories listed on a product match up with the listed
nutrients, you may do the following calculation: multiply the listed weight of
each component by the number of calories per gram as shown below, and add them
together for the total number of calories.
|
Carbohydrate (excluding dietary fiber) |
4 calories per gram |
|
Protein |
4 calories per gram |
|
Fats |
9 calories per gram |
For example, a product labeled as containing 25 grams of carbohydrates, 15
grams of protein, and 5 grams of fat would have 100 calories from carbohydrates
(25 x 4), 60 calories from protein (15 x 4), and 45 calories from fat (5 x 9),
for a total of 205 calories. Carbohydrates would, therefore, contribute about
49% of the calories, protein would contribute about 29%, and fat would
contribute about 22%.
If your total is more than a few calories off from what the product label
states, the product may be hiding something. (Note that manufacturers are
allowed to round numbers and certain sugar and fat substitutes may have fewer
calories than normal sugars and fats, so don't expect the calculated calories
to match the label exactly; allow leeway of up to 10% of the total calories).
Know the nutritional content of the liquids with which
you mix a powder:
The nutritional profile of a drink made from powder is obviously going to
depend on the liquid with which it is mixed. Below is a listing of the
nutritional content of some of the more common liquids used, besides water.
Figures shown are based on one cup of liquid (8 fluid ounces), but be aware
that the suggested amount of liquid per serving will vary by product. In
general, most powders suggest about one cup of liquid per 40 grams of powder.
|
Nutrients in Common Liquids Mixed with
Nutrition Powders |
||||
|
Liquid (one cup) |
Calories |
Carbohydrate |
Fat |
Protein |
|
Whole Milk |
146 |
11 g |
8 g |
8 g |
|
Skim Milk |
86 |
12 g |
0 g |
8 g |
|
Chocolate Milk, Reduced Fat |
190 |
30 g |
5 g |
7 g |
|
Orange Juice |
110 |
25 g |
1 g |
2 g |
|
Apple Juice |
117 |
29 g |
0 g |
0 g |
|
Source: U.S. Department of Agriculture,
Agricultural Research Service. 2006. USDA Nutrient Database for Standard
Reference, Release 19. Nutrient Data Laboratory Home Page, http://www.nal.usda.gov/fnic/foodcomp/search/. |
||||
When to take:
A review of 34 clinical trials in which people supplemented with protein and
participated in resistance exercise found that consuming protein
supplements with meals, rather than between meals, resulted in
a greater percentage of people experiencing an increase in muscle (94% vs. 90%)
as well as reductions in fat (87% vs. 59%). As to the reason for the
difference, the researchers speculated that supplementing with protein between
meals may be akin to "snacking," while having protein at meal time
"may displace some of the energy that otherwise would have been consumed
at that meal time." (Hudson, Nutr Rev 2018).
Taking into consideration that a study, noted above, found that taking protein after,
rather than before resistance exercise, resulted in greater metabolic
improvement and fat loss, it may be best, if possible, to supplement
with protein after exercise, preferably as part of meal.
It may also be beneficial to spread out total protein intake more
evenly across meals, rather than skewing protein intake toward one meal,
such as dinner. A small study of overweight-to-obese older adults put on a
regimen of physical activity and dieting for one year found that transition to
a more even protein intake across meals was associated with a greater decline
in BMI (body mass index) and abdominal subcutaneous fat (Farsijani, J Nutr Health Aging 2020). To
reach theoretical "maximal protein stimulation" levels (as discussed
in the What It Does section) at each meal, a
study in England showed that people in all age groups would need to consume
more protein at breakfast, and older people (i.e., in their 70s and 80s) would
also need to increase protein intake at lunch -- when they tend to consume
significantly less protein than younger people (Smeunix, Fron Nutr 2020).
To help reduce the increase in blood sugar after a meal, consuming
20 grams of whey protein 15 minutes before or during the meal has been shown to
help in obese, insulin-resistant men (Allerton, Br J Nutr 2018).
Proper Storage:
If in a dry, powder form, protein is quite stable and should not degrade at
temperatures normally experienced during shipping and storage. Although higher
temperatures may change a protein's molecular shape, it will continue to
provide the same nutritional benefits. Humidity or water may cause protein
powders to clump but not break down.
To reduce exposure to moisture, especially in humid climates, it's best to
store powdered products in several small containers rather than one large
container. Do not store these supplements in the refrigerator, because if you
remove them and leave them open, moisture may accumulate due to condensation.
Cautions and Concerns:
Protein
powders and drinks may cause gastrointestinal discomfort such
as gas, bloating, diarrhea or constipation, in some people.
People with lactose intolerance, in particular, may want to avoid
milk-based proteins, other than whey isolate, as they may contain lactose. Some
products include lactase enzyme to help digest the lactose that is present.
Allergic reactions to whey protein supplements
may occur even in individuals who do not have allergic reactions to milk — the
source of whey. This was reported in four individuals who had symptoms such as
gastrointestinal distress, hives and swelling of the skin, and feeling faint,
shortly after consuming whey protein powders or bars (various brands)
containing a combination of whey protein concentrate and isolates. Allergen
testing confirmed that three of the individuals were allergic to their whey
protein supplement, even though two of the individuals were not allergic to
cow's milk. The physicians who reported the cases theorized that "there
may be factors associated with supplement preparation and processing which
result in more immunogenic antigens." (Rorie, J Allergy Clin Immunol 2019).
Allergic reactions to cricket protein can also occur in people allergic to
shellfish or insects.
It has been hypothesized that high-protein diets can
increase calcium turnover from bone, resulting in calcium loss,
and it has been suggested that this can be stabilized by the daily consumption
of 300 mg of calcium (the equivalent to one 8 oz. glass of milk) on top of your
basic daily calcium intake (many protein powders provide extra calcium).However,
several studies have not shown a negative effect on bone from
increased protein intake, including a 6-month study among 24
athletically-trained women. Half the women boosted their protein intake by an
average of 87% -- mostly with protein powders, but there were no changes in
bone mineral density or bone mineral content in either group (Antonio, J Int Soc Sports Nutr 2018).
It has also been hypothesized that high protein intake
may increase the risk of dehydration by increasing urea
production and urine output. For this reason, increasing water and fluid intake
when consuming a high protein diet or protein supplements has sometimes been
advised. Of course, it's always important to stay adequately hydrated. However, there
is no evidence that high protein intakes increase the need for fluids or
increase risk of dehydration in healthy individuals with normal kidney function
who maintain their normal fluid intake. For example, a small study among
healthy young men found that consuming a very high protein diet (3.6 mg/kg of
bodyweight per day, equivalent to 245 grams of protein for a 150 lb. individual
— 4 ˝ times the RDA for men) and normal water intake for
three months modestly increased blood urea nitrogen (BUN) but had a minimal
effect on fluid status. The researchers concluded that consumption of protein
at levels in excess of the upper range of the Dietary Reference Intakes was
"not associated with negative effects on hydration status" (Martin, J Am Diet Assoc 2006).
Individuals with kidney disease should consult with their
physician concerning safe protein and fluid intakes, and the risk of
dehydration (Martin, Nutr Metab (Lond) 2005).
Protein intake is not associated with
decreased kidney function in healthy older adults who do not have
kidney disease. For example, a large, 10-year study of over 1,600 women ages 42
to 68 found that among women who started out with normal kidney function, there
was no association between the amount or type of protein they consumed and
decreased kidney function over time. On the other hand, women who started out
with mildly decreased kidney function showed some worsening with
increasing amounts of protein intake, particularly from meat protein. Dairy
or vegetable protein was not associated with worsening kidney function (Knight, Ann Intern Med 2003). To
be safe, some experts recommend that individuals with normal kidney function
but who are at high risk for developing kidney disease (i.e., those with
diabetes, high blood pressure or who have just one kidney) limit protein intake to
0.45 gram of protein per pound of bodyweight per day (about 75 grams of protein
a day for a 150 lb. individual) (Kalantar-Zadeh, Nephrol Dial
Transplant 2019). In healthy adults, however, overly restricting protein
intake does not prevent, and may actually worsen, age-related decline
in kidney function (Walser, The National Academies
Press 1999).
Carnitine is sometimes found in protein powders, although it is not known
to be of benefit in sports. Recent research suggests that carnitine
intake may potentially contribute to cardiovascular disease in certain
people. People who eat red meat (as opposed to vegetarians and vegans) maintain
organisms in their gut which digest carnitine to the compound TMA, which is
then converted in the liver to the compound TMAO which appears to advance
atherosclerosis (hardening of the arteries) by reducing the normal clearing of
cholesterol (Koeth, Nature Medicine 2013).
Supplementing with L-carnitine may potentially foster growth of these
organisms, increase levels of TMAO, and have negative long-term cardiovascular
effects. Unless it is medically necessary for you to take L-carnitine, it may
be prudent to avoid long-term use at high doses (several hundred milligrams).
Similarly, as has long been known, it may be prudent to reduce consumption of
red meat, a major source of L-carnitine.
Protein consumption can cause dangerously high blood levels of ammonia in
people with urea cycle disorder, a rare genetic disorder in which
the body is deficient in one or more of the enzymes that help to break down
ammonia — a byproduct of protein digestion (Genetic and Rare Diseases
Information Center 2017). In people with this disorder, high levels
of ammonia can build up in the blood and the brain, which can lead to
irreversible brain damage, coma or death. Although relatively rare, occurring in
an estimated 1 in every 8,500 births, milder forms of this disorder can go
undetected in adults who have enough enzymes to handle typical protein intakes.
However, even in people with milder forms of the disorder, stressors such as
viruses, high protein intake, excessive exercise or dieting, or surgery can
cause dangerously high blood levels of ammonia. For example, a 25-year-old
woman who did not know she had the disorder became unconscious and died after
taking protein supplements, eating protein-rich foods, and exercising in
preparation for a fitness competition (See the Warning about
this).
Be aware
that following a diet consisting mainly of plant protein can reduce
intakes of vitamin B-12 and iodine. A 12-week study in healthy people
(average age 48) showed that those put on a diet in which 70% of protein was
plant-based developed 20% lower blood levels of a marker of vitamin B-12 status
(holo-transcobalamin II) and about 35% lower 24-hour urinary iodine excretion
than those put on a diet in which 70% of protein was from animals. While
holo-transcobalamin levels were still considered adequate for most people in
the plant-protein group, it was inadequate for about 10% of them compared to
only 2% of those in the animal-protein group. This suggests that
supplementation with vitamin B-12 and, possibly, iodine may be necessary for
some people who replace significant amounts of animal protein in their diet
with plant protein. It is notable that none of those in the plant-protein group
were allowed to take dietary supplements or consume fortified food products,
and for vegetarians, fortified cereals, milk and yogurt may provide sufficient
B-12. There was no difference in blood levels of zinc, folate, or iron,
although interestingly, those in the plant-protein group actually had highest
iron intakes (Pellinen, Eur J Nutr 2021).
To further assist consumers, ConsumerLab.com licenses its flask-shaped CL Seal
of Approved Quality (see The CL Seal) to manufacturers for use on
labels of products that have passed its testing. ConsumerLab.com will
periodically re-evaluate these products to ensure their compliance with
ConsumerLab.com's standards.
Information on this site
is provided for informational purposes only. It is not an endorsement of any
product nor is it meant to substitute for the advice provided by physicians or
other healthcare professionals. The information contained herein should not be
used for diagnosing or treating a health problem or disease. Consumers should
inform their healthcare providers of the dietary supplements they take.
Latest Clinical Research Updates for Protein Powders
Nutrients In Jeopardy With a Plant-Based Diet?
11/30/2021
Which nutrients are in
jeopardy when one switches from animal to plant-based proteins? Find out what a
recent study showed in the Concerns and Cautions section of
our Protein Supplements Review. Also see
our Top Picks among protein supplements.
10/23/2021
How does the amino acid
quality and digestibility of pea protein compare to casein? Find out what a new
study showed in the ConsumerTips section of our Protein
Supplements Review, which also explains the differences between whey, soy,
rice, and other sources of protein. Also see our Top Picks among protein powders, including
our Top Pick for pea protein.
Whey vs Rice and Potato Protein
6/27/2021
Whey, rice and potato
proteins were found to have different effects on blood sugar and insulin levels
in a recent study. Find out how they differ. You can also learn
more about these and other protein sources in the ConsumerTips section of our Protein
Powders, Shakes and Drinks Review. Also see our Top Picks among
protein powders.
10/27/2020
People on dialysis (for
kidney failure) may lose protein, but do all dialysis patients benefit from
protein supplementation? Find out what studies are showing in the What It Does section
of our Protein Supplements Review. Also see our Top Picks for protein
powders, shakes and drinks.
Can Whey Protein Control Hunger?
10/06/2020
Can drinking a whey
protein shake help control hunger in people who are overweight? Find out what a
recent study showed in the What It Does section
of our Protein Supplements Review. Also see our Top Picks among protein powders, shakes and drinks.
Related CL Answers (28)