What is Witch Hazel?

Witch hazel (Hamamelis virginiana) is a shrub that grows on the eastern coast of North America. It has leathery leaves and yellow, stringy flowers that bloom in the fall [R].

Witch hazel trees grow on rocky slopes near stream beds, in ravines and in forest understories, and can reach heights of up to 13 meters [R].

Native Americans have traditionally used it to treat a variety of conditions including insect bites, sore muscles, cuts, rashes, sunburn, hemorrhoids, and bruises [R].

Witch hazel is safe and approved for external use and can be purchased over the counter in the form of creams, infused pads, and liquids [R].

Snapshot

Proponents:

• Relieves skin irritation
• Helps with bites, wounds, and sunburns
• May help with acne
• May reduce vaginal dryness

Skeptics:

• Most uses lack stronger clinical evidence
• May not help with atopic dermatitis
• Water-based products may not be effective

Components

Many of the positive health effects of witch hazel have been linked to polyphenolic molecules [R, R].

A subset of these molecules, commonly known as tannins, is what gives the plant its anti-inflammatory, antioxidant, blood vessel-narrowing (vasoconstrictive), and skin-tightening (astringent) effects. Tannins make up between 3 to 12% of the leaves and bark of witch hazel [R, R].

These tannins include catechins, gallotannins, cyanidin, and proanthocyanidins [R].

Mechanism of Action

Researchers believe that the antioxidant effects of witch hazel come from the activity of gallate esters (a specific chemical structure attached to tannins), as well as flavonoids, which protect DNA from damage by eliminating free radicals [R, R, R, R].

Elastin and collagen proteins are produced by skin cells and are essential for giving the skin its flexibility and strength. Witch hazel inhibits the enzymes that break down elastin and collagen (elastase and collagenase), which helps to keep the skin intact and flexible, and also promotes healing [R, R].

The polyphenols extracted from witch hazel can also inhibit

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What Are Binaural Beats?

Binaural beats are an auditory illusion perceived by the brain when two slightly different frequencies of sound are played into each ear (bi – two, aural- ear).

When wearing earphones that are playing slightly different notes in each ear, our brain perceives the volume to pulse (oscillate) at a fixed rate. This is called a ‘beat.’

The same phenomenon arises when tuning two guitar strings. As the frequencies get closer together, we begin to hear a slow pulsing beat between the notes of the two strings.

The rate (frequency) of a beat is equal to the difference between the two frequencies being played. For example, if you listened to two frequencies at 200 Hz and 210 Hz, the beat would arise at a frequency of 10 Hz (or 10 “beats” per second).

But how could this affect the brain? To answer this question, we first need to know about brain waves.

Proponents:

• May reduce anxiety and improve mood
• May improve focus, attention, and memory
• May increase creativity and cognitive flexibility
• May help you enter a meditative state
• Linked to improved sleep quality

Skeptics:

• May increase feelings of depression
• Some participants reported negative emotions (anger, confusion, anxiety)
• Available studies are small and low quality

Rhythm & Your Brain

The part of our brains that first processes sound inputs from both ears is called the superior olivary complex, which is located in the brain stem. This brain area allows us to identify the direction of sounds [R].

Fig (a): Schematic depiction of the seeds in the auditory pathway: Primary auditory cortex (PAC); medial geniculate nucleus (MGN); inferior colliculus (IC); and superior olivary complex (SOC) [R].

The superior olivary complex can be ‘tricked’ into hearing a beat when it senses two close frequencies; it responds by synchronizing neuronal activity in other parts of the brain. In other words, this part of the brain acts like the conductor of an orchestra, coordinating and synchronizing the activities of many neurons throughout the rest of the brain.

This synchronization of neural activity across different brain areas is called “entrainment” and is the main way that binaural beats cause changes in our brain waves [R,

The post 9 Benefits of Binaural Beats (Sleep, Focus, Meditation) appeared first on SelfHacked.