We need small amounts of manganese for stronger bones and sharper brains. It may also protect against depression, seizures, diabetes, and cancer, but beware when supplementing with this metal, because higher doses can be toxic.<\/p>\n
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Manganese is a trace metal essential<\/strong> to all forms of life. It is required for normal development<\/strong>, growth<\/strong>, and function of our bodies<\/strong> [R<\/a>, R<\/a>, R<\/a>].<\/p>\n Manganese serves as an essential part of important enzymes such as glutamine<\/a> synthetase and superoxide dismutase<\/a> [R<\/a>, R<\/a>]. These enzymes play a role in:<\/p>\n Manganese is a required part of a healthy diet. However, despite its many benefits, exposure to excess levels can be toxic<\/strong><\/a>. <\/strong>That is why it is necessary to keep manganese levels in balance [R<\/a>].<\/p>\n Because it’s found pretty much everywhere, you\u2019re more likely to have excess manganese than to be deficient<\/strong>.<\/p>\n Keep in mind that this section discusses the biological role of manganese, and not necessarily the benefits of taking manganese supplements.<\/strong> These functions may suffer if someone is deficient in manganese, but more is not always better, as too much manganese can be harmful. <\/strong>If you are concerned about your manganese intake, talk to your doctor to see if increased dietary manganese intake is a good idea for you.<\/p>\n Manganese, <\/strong>within antioxidant enzymes, protects against<\/strong> oxidative stress<\/strong><\/a> and cell damage<\/strong> [R<\/a>].<\/p>\n Manganese superoxide dismutase <\/strong>(MnSOD<\/strong><\/a>) is the cell\u2019s most important antioxidant enzyme<\/strong>. It neutralizes the toxic effects of reactive oxygen species<\/a> (ROS) in mitochondria. MnSOD also protects cells from inflammation and cancer-causing agents, such as toxic chemicals and radioactive materials [R<\/a>, R<\/a>, R<\/a>].<\/p>\n If you are deficient in manganese, you will have reduced MnSOD activity, which leads to cellular damage and dysfunction [R<\/a>].<\/p>\n Support your MnSOD by making sure you get enough manganese. In a study of 47 young women, those taking manganese supplements had lower <\/strong>oxidative stress<\/strong><\/a> [R<\/a>].<\/p>\n Several enzymes important for brain function work only in the presence of manganese [R<\/a>].<\/p>\n In a study of 296 school-age children, children with higher urine manganese levels had higher <\/strong>IQ<\/strong><\/a>. This relationship was especially pronounced in girls [R<\/a>].<\/p>\n In another study of 404 school-age children, those with very low or very high blood and hair levels of manganese had lower IQ scores. Children in the middle of the scale, with roughly average blood and hair levels of manganese, had the highest IQ scores [R<\/a>].<\/p>\n Finally, in a study of over 1,200 children, girls that had higher exposure to manganese before they were born performed better in cognitive tests. However, in the same study, high manganese exposure in early life adversely affected children’s behavior. Once again, balanced manganese levels are important [R<\/a>].<\/p>\n Low levels of manganese may contribute to depression<\/a> [R<\/a>].<\/p>\n In a study of over 2,000 Japanese people, low dietary manganese was associated with a higher risk of depression. Similarly, in another study of 1,745 pregnant Japanese women, those with higher manganese intake were less likely to experience depressive symptoms during pregnancy [R<\/a>, R<\/a>].<\/p>\n Manganese superoxide dismutase (MnSOD) likely plays a role. In a study of 236 people, those who had experienced multiple episodes of depression had lower levels of MnSOD [R<\/a>].<\/p>\n In both humans and animals, there is a link between low blood manganese and seizures [R<\/a>].<\/p>\n People with epilepsy have lower blood manganese, while long-term dietary manganese deficiency causes seizures in rats [R<\/a>, R<\/a>].<\/p>\n Some studies suggest that neurological symptoms in epileptics may correlate with low brain manganese. However, it’s not clear if low levels of manganese make people more likely to experience seizures, or if seizures deplete manganese levels [R<\/a>, R<\/a>].<\/p>\n A U.S. study found that children with autism had marginally lower levels of tooth manganese, <\/strong>which reflects their exposure to this metal [R<\/a>].<\/p>\n Autism is associated with an increase of glutamate<\/a> in the brain [R<\/a>]. Glutamine synthetase, an enzyme that converts glutamate into glutamine, contains manganese [R<\/a>]. Therefore, manganese deficiency may result in higher brain glutamate.<\/p>\n Furthermore, mitochondrial dysfunction is a key feature of autism. Manganese superoxide dismutase (MnSOD) protects the mitochondria from oxidative damage and dysfunction; if autistic people are deficient in manganese, they will not produce enough MnSOD to protect their mitochondria [R<\/a>].<\/p>\n Finally, people with autism have low levels of beneficial Lactobacillus<\/em> bacteria in their gut. These bacteria depend on manganese for antioxidant protection. Given enough manganese, Lactobacillus<\/em> probiotics<\/a> can lower the anxiety<\/a> people with autism often experience [R<\/a>].<\/p>\n According to a meta-analysis of 17 studies with over 2000 people, patients with Alzheimer\u2019s disease have significantly lower blood manganese levels compared to their healthy counterparts<\/strong>. Therefore, manganese deficiency may be a risk factor for Alzheimer\u2019s, but causal proof is still missing [R<\/a>].<\/p>\n Mitochondrial dysfunction and an increase of glutamate in the brain are also associated with Alzheimer\u2019s disease. As discussed in the section on autism, both of these can be associated with manganese deficiency [R<\/a>].<\/p>\n Manganese is a part of various enzymes involved in cartilage and bone production. It also plays an essential role in incorporating<\/strong> calcium<\/strong><\/a> into growing bones<\/strong> [R<\/a>, R<\/a>].<\/p>\n Some genetic disorders make it difficult for people\u2019s cells to transport manganese. This type of manganese deficiency can cause short stature, also known as dwarfism, likely due to bone growth issues [R<\/a>, R<\/a>].<\/p>\n Manganese supplementation effectively reduces the loss of bone mass in female rat models of postmenopausal osteoporosis [R<\/a>].<\/p>\n In multiple animal studies, diets low in manganese interfered with cartilage production and resulted in low bone density [R<\/a>].<\/p>\n Manganese is important for sperm cells to be able to \u201cswim;\u201d<\/strong> thus, manganese deficiency can reduce fertility in men [R<\/a>, R<\/a>].<\/p>\n Both male and female animals experience reduced fertility if they are manganese deficient: females develop ovulation issues, while the testicles of males may degenerate [R<\/a>].<\/p>\n In a study of 96 women, those with premenstrual syndrome (PMS<\/a>) had lower blood manganese levels. In a small-scale study, reducing dietary manganese intensified mood and pain<\/a> symptoms during PMS in 10 women [R<\/a>, R<\/a>].<\/p>\n However, a larger study of over 3000 women found no relationship between manganese and PMS [R<\/a>].<\/p>\n Several studies have reported lower blood levels of manganese in diabetic patients <\/strong>[R<\/a>, R<\/a>, R<\/a>, R<\/a>].<\/p>\n In a large study of over 10,000 people, higher manganese intake in the diet was associated with a lower incidence of type 2 diabetes and lower levels of HbA1c<\/a>, an important marker of long-term blood sugar [R<\/a>].<\/p>\n However, another study of 3200 people found a U-shaped association between blood manganese levels and diabetes. That is, diabetes risk increased for both the lowest and highest levels of manganese [R<\/a>].<\/p>\n In rats, dietary manganese deficiency can impair<\/strong> insulin<\/strong><\/a> production<\/strong>. In addition, manganese supplementation improves<\/strong> glucose<\/strong><\/a> tolerance and insulin production in mice on a<\/strong> high-fat diet<\/strong><\/a> [R<\/a>, R<\/a>].<\/p>\n Finally, manganese supplementation can also increase adiponectin<\/a> in diabetic rats. Adiponectin, a fat-burning hormone, reduces the risk of metabolic syndrome and diabetes [R<\/a>].<\/p>\n Metabolic syndrome is a cluster of conditions that occur together and increase your risk of heart disease and diabetes. You have metabolic syndrome if you have three of the following [R<\/a>]:<\/p>\n In a study of 550 Chinese adults, those with higher manganese intake in their diets had a significantly lower risk of developing metabolic syndrome<\/strong> [R<\/a>].<\/p>\n In another study of over 2000 Chinese adults, men with a higher manganese intake were less obese and had lower blood triglycerides<\/a>. However, higher manganese intake was also associated with low HDL<\/a> (good) cholesterol<\/a> in both men and women [R<\/a>].<\/p>\n Meanwhile, in over 5000 Korean adults, women who had metabolic syndrome had lower daily intakes of manganese [R<\/a>].<\/p>\n In a study of over 3800 people, higher urinary manganese was linked with lower systolic and diastolic blood pressure. In another study of 255 people, mid-range manganese levels were associated with lower blood pressure [R<\/a>, R<\/a>].<\/p>\n In animals, when the mother is deficient in manganese, the offspring are more susceptible to high-fat-diet-induced obesity, high cholesterol, and inflammation [R<\/a>].<\/p>\n However, it’s difficult to confirm the association between dietary manganese intake and metabolic syndrome. It may be the case, for example, that people who eat a healthier diet also happen to have higher manganese levels.<\/p>\n In fact, people eating plant-based diets (e.g. vegetarians) naturally have higher manganese intakes because plant foods are higher in manganese<\/strong>. These diets are linked with lower cholesterol and fewer metabolic issues, but not necessarily because of their manganese content [R<\/a>, R<\/a>].<\/p>\n Manganese is an essential component of manganese superoxide dismutase <\/strong>(MnSOD<\/strong>, SOD2<\/strong><\/a>), an enzyme that helps combat cancer <\/strong>[R<\/a>, R<\/a>, R<\/a>].<\/p>\n According to a meta-analysis of 11 studies with over 1300 people, women with breast cancer had lower manganese levels than healthy women [R<\/a>].<\/p>\n In support of these findings, the level of MnSOD gets reduced prior to the formation of cancer in mice [R<\/a>].<\/p>\n This enzyme may help fight many types of cancer, but not all of them. Many human cancers have low levels of MnSOD. However, some cancers actually have high levels of this enzyme [R<\/a>].<\/p>\n A combination of proteins containing manganese improved the appearance of several signs of skin damage from the <\/strong>sun<\/strong><\/a> in 15 female subjects. The treatment, applied directly to the skin, significantly improved hyperpigmentation, or the appearance of patchy dark spots [R<\/a>].<\/p>\n We get most of our manganese through our diet [R<\/a>].<\/p>\n Legumes, rice, nuts, and whole grains contain the highest levels of manganese. This metal is also found in seafood, seeds, chocolate, tea, leafy green vegetables, spices, soybeans, and some fruits such as pineapple, blueberries<\/a>, and acai. A cup of tea contains as much as 1.3 mg of manganese [R<\/a>, R<\/a>, R<\/a>, R<\/a>, R<\/a>].<\/p>\n\n
<\/a>Biological Role of Manganese<\/strong><\/span><\/h2>\n
<\/a>1) Antioxidant Enzymes<\/strong><\/span><\/h3>\n
<\/a>2) Neurological Health<\/strong><\/span><\/h3>\n
<\/a>Cognitive Function<\/h4>\n
<\/a>Depression<\/h4>\n
<\/a>Seizures<\/h4>\n
<\/a>Autism<\/h4>\n
<\/a>Alzheimer\u2019s<\/h4>\n
<\/a>3) Cartilage and Bones<\/strong><\/span><\/h3>\n
<\/a>4) Reproductive Health<\/strong><\/span><\/h3>\n
<\/a>Fertility<\/h4>\n
<\/a>Premenstrual Syndrome<\/h4>\n
<\/a>9) Diabetes<\/strong><\/span><\/h3>\n
<\/a>10) Metabolic Syndrome<\/strong><\/span><\/h3>\n
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<\/a>12) Cancer Prevention<\/strong><\/span><\/h3>\n
<\/a>13) Skin Repair<\/strong><\/span><\/h3>\n
<\/a>Manganese in Food and Supplements<\/strong><\/span><\/h2>\n
<\/a>Dietary Sources<\/strong><\/span><\/h3>\n