Exploring Vitamin E

Vitamin E is a fat-soluble vitamin with several forms; its main role is to act as an antioxidant, scavenging free radicals that can damage cells. Vitamin E came to public attention in the 1980s when scientists began to understand that free radical damage was involved in the early stages of artery-clogging atherosclerosis, and might also contribute to cancer, vision loss, and a host of other chronic conditions. In this blog, we will explore the types of Vitamin E and its antioxidant properties, along with foods rich in Vitamin E and the health benefits they provide in both skincare and through consumption.

What is Vitamin E?

Vitamin E is an antioxidant compound obtained from plant sources in the diet. Vitamin E is not a singular substance; it’s a collective term for a family of eight homologous molecules that are synthesized naturally by plants from homogentisic acid.

Vitamin E is a series of organic compounds consisting of various methylated phenols. These compounds can act as an antioxidant by donating a hydrogen atom to reduce free radicals and have a hydrophobic side chain, which allows for penetration into biological membranes.

The eight homologs are split into two groups: tocopherols and tocotrienols. The tocopherols and tocotrienols have four homologs: alpha, beta, gamma, and delta. Each form has a slightly different biological activity. However, all of these various derivatives are referred to simply as “Vitamin E.”

Historically, only one out of the eight has appeared to have the most nutritional importance: the d-alpha-tocopherol isomer form. The d-alpha-tocopherol isomer form is commonly called Vitamin E on nutrition/supplement labels and is also the only form that can be referred to as the RDA, or Recommended Daily Allowance, for Vitamin E.

The alpha form of tocopherol was originally designated d-alpha-tocopherol on the basis of its optical activity. This means that you can “see” more of this specific compound in your body’s chemical signature. It makes up about 90% of the tocopherol found in humans. Even in your blood plasma, around 83% of the Vitamin E found is d-alpha-tocopherol.

It’s been found that long-term supplementation with just a d-alpha-tocopherol Vitamin E supplement results in blood plasma levels of d-gamma-tocopherols being lowered by 30 to 50%. Since your body still needs this other form, some researchers now recommend to select one with mixed tocopherols.1

Types of Vitamin E

Commercially available sources of Vitamin E can be classified into several distinct categories or types, such as 2, 3:

Natural Vitamin E

This is what most people refer to as Vitamin E; it’s the non-esterified form of d-alpha-tocopherol and occurs in nature, primarily in vegetable oils like soy and sunflower oil.

Semi-Synthetic, Esters

Manufacturers commonly convert the phenol form of the vitamin, with a free hydroxyl group, to esters, using acetic or succinic acid. An ester is a salt formed by a carboxylic acid and an alcohol (tocopherol is the alcohol in this case). These esters are more stable as they are less susceptible to oxidation during storage. In their stored form, they are not classified as antioxidants.

You have to consume these ester forms to “activate” them and unlock their antioxidant properties. Your gut produces an enzyme called esterase that de-esterfies the compound and allows your body to absorb the compound as free tocopherol. Several studies indicate the rate of absorption of these forms of tocopheryl esters and free tocopherol have similar bioavailability.

Alpha-tocopherol

Current literature suggests the primary role in the body of Vitamin E is to function as a major lipid antioxidant for free radicals formed from normal cellular metabolism. Free radicals are destructive to the cell membrane and other body components.

Vitamin E acts as an antioxidant, a molecule capable of inhibiting the oxidation of other molecules, which makes the free radicals unable to damage your cells. Other antioxidants, such as Vitamin C, are capable of regenerating the antioxidant capacity of alpha-tocopherol. Additionally, alpha-tocopherol also protects the fats in low-density lipoproteins (LDL) from oxidation, possibly reducing risk of cardiovascular disease in the process.

Gamma-Tocopherol

Gamma-tocopherol is the major form of Vitamin E ingested in the U.S. diet. It was previously assumed that this form was not important as the body naturally has much higher concentrations of the alpha form. The blood levels of gamma-tocopherol are generally 10-times lower than those of alpha-tocopherol.

However, more recent studies suggest that gamma-tocopherol picks up the slack left by the alpha form. It appears to scavenge different types of free radicals which can damage proteins, lipids, and even your DNA.

Additionally, gamma-tocopherol can inhibit inflammation by reducing cyclooxygenase activity. Studies have also shown higher plasma concentrations of gamma-tocopherol are associated with reduced incidences of prostate cancer.

Tocotrienols

Studies on on tocotrienols indicate they may have significant antioxidant and anti-cancer effects. Tocotrienols appear to act on a specific enzyme called HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A reductase) that’s involved in cholesterol production in the liver. Tocotrienols suppress the production of this enzyme, which may result in less cholesterol being manufactured by liver cells.

The Benefits of Vitamin E in Skincare

Some potential skin benefits of Vitamin E include:

Vitamin E is Moisturizing

Researchers have found that products containing Vitamin E can very effectively moisturize the skin. A few studies have shown that the topical application of Vitamin E can improve the skin’s water-binding capacity after two to four weeks of use.4,5  The research also found that Vitamin E can be more moisturizing than other common ingredients used in skincare.

Vitamin E Can Help Fight UV-Related Skin Damage

Oregan State University highlights several studies suggesting that Vitamin E could fight skin damage from sun exposure. Though it’s been shown that it’s possible that adding Vitamin E to sunscreen provides some additional skin benefits, it is important to note that Vitamin E itself is not an effective sunscreen.

Multiple studies have found that the combination of Vitamin C and Vitamin E protects the skin against UV damage.6 Human subjects orally co-supplemented with Vitamins C and E show increased Minimal Erythemal Dose (MED), which is a measure of photoprotection from UV light on the skin.7

Vitamin E Can Promote Wound Healing

The author of a review article in the International Wound Journal suggests that Vitamin E can promote wound healing. The theory is that because Vitamin E deficiencies can slow wound healing, a good amount of this nutrient could have the opposite effect.8

Vitamin E Possesses Anti-Inflammatory Properties

Inflammation is the body’s reaction to an injury or infection; it can cause pain, discoloration, and swelling. Many common skin conditions cause inflammation, including acne. A 2020 study reviewed 26 clinical trials and found evidence that Vitamin E can reduce inflammation in adults.9

Vitamin E May Reduce Hyperpigmentation

Dark patches on your skin can be caused by too much melanin, which is triggered by hormones or other causes. Called Melasma, this condition is believed to be treatable through the use of topical Vitamin E. Studies show that hyperpigmentation may be only moderately affected by using topical Vitamin E oil, but the most effective way to use Vitamin E to treat hyperpigmentation is to pair it with Vitamin C.10

Vitamin E May Prevent Aging And Wrinkles 

Vitamin E affects blood circulation, which is why many people notice a difference in the firmness and structure of their skin after the topical use of Vitamin E. A 2013 review tells us that Vitamin E and other natural ingredients rich in antioxidants are generally accepted as a treatment for delaying wrinkles due to photoaging.11

Foods Vitamin E Is Found In

Numerous foods provide Vitamin E. Nuts, seeds, and vegetable oils are among the best sources of alpha-tocopherol, and significant amounts are available in green leafy vegetables and fortified cereals. 

Here are 10 foods that contain large amounts of Vitamin E: 

Sunflower Seeds (Vitamin E per 1 oz handful:( 7.4 mg or 49% DV), Vitamin E per 100g (26.1 mg or 178% DV) Vitamin E per 200 calories (9 mg or 60% DV)

 

Almonds (Vitamin E per 1 oz handful:( 7.3 mg or 49% DV), Vitamin E per 100g (25.6 mg or 171% DV) Vitamin E per 200 calories (8.9 mg or 59% DV)

 

Avocados (Vitamin E per 1 oz avodaco):( 4.2 mg or 28% DV), Vitamin E per 100g (2.1 mg or 14% DV) Vitamin E per 200 calories (2.7 mg or 17% DV)

 

Spinach (Vitamin E per cup cooked):( 3.7 mg or 25% DV), Vitamin E per 100g (2.1 mg or 14% DV) Vitamin E per 200 calories (18.1 mg or 121% DV)

 

Butternut Squash (Vitamin E per 1 cup cooked)l:( 2.6 mg or 18% DV), Vitamin E per 100g (1.3 mg or 9% DV) Vitamin E per 200 calories (6.5 mg or 43% DV)

 

Kiwifruit (Vitamin E per cup:( 2.6 mg or 18% DV), Vitamin E per 100g (1.5 mg or 10% DV) Vitamin E per 200 calories (4.8 mg or 32% DV)

 

Broccoli (Vitamin E per cup cookedl:( 2.3 mg or 15% DV), Vitamin E per 100g (1.5 mg or 10% DV) Vitamin E per 200 calories (8.3 mg or 55% DV)

 

Trout (Vitamin E per fillet:( 2 mg or 13% DV), Vitamin E per 100g (2.8 mg or 19% DV) Vitamin E per 200 calories (3.3 mg or 22% DV)

 

Olive Oil (Vitamin E per tablespoon:( 1.9 mg or 13% DV), Vitamin E per 100g (14.4 mg or 96% DV) Vitamin E per 200 calories (3.2 mg or 22% DV)

 

Shrimp (Vitamin E per 3 oz:( 1.9 mg or 12% DV), Vitamin E per 100g (2.2 mg or 15% DV) Vitamin E per 200 calories (3.7 mg or 25% DV)

The Health Benefits of Vitamin E

Vitamin E plays many roles in your body. While it’s best known for its antioxidant effects, Vitamin E is also needed for proper immune function and cellular signaling. Here are a few potential health benefits of Vitamin E:

Vitamin E May Reduce Markers Of Oxidative Stress And Improve Antioxidant Defenses

Oxidative stress is a condition that occurs when there’s an imbalance between your body’s antioxidant defenses and the production and accumulation of compounds called reactive oxygen species (ROS). This can lead to cellular damage and increased disease risk.12

Because Vitamin E acts as a powerful antioxidant in the body, studies have shown that supplementing with high doses of it can reduce markers of oxidative stress and boost antioxidant defenses in some populations.13

For example, a 2018 study in 54 people with diabetic nephropathy — kidney damage caused by high blood sugar — found that supplementing with 800 IU of Vitamin E per day for 12 weeks significantly increased levels of glutathione peroxidase (GPx) compared with a placebo.14 GPx is a group of antioxidant enzymes that protect your cells from oxidative damage.

Vitamin E May Reduce Heart Disease Risk Factors

Having high blood pressure and high levels of blood lipids such as LDL cholesterol and triglycerides may increase your risk of developing heart disease. Promisingly, research suggests that Vitamin E supplements may help reduce heart disease risk factors such as these in some people.

A 2019 review of 18 studies found that, compared with placebo treatments, Vitamin E supplements significantly reduced systolic but not diastolic blood pressure — the top and bottom numbers of blood pressure readings, respectively.15

Some studies also show that taking Vitamin E with omega-3 supplements may reduce LDL and triglyceride levels in people with metabolic syndrome — a cluster of conditions, including high blood fat levels, that increases the risk of heart disease and other health conditions.16

Vitamin E May Benefit Those With Nonalcoholic Fatty Liver Disease (NAFLD)

NAFLD includes a number of conditions that cause an accumulation of fat in the liver in people who drink little or no alcohol. According to research findings, Vitamin E may improve some aspects of health in people with NAFLD.

A 2021 review of eight studies found that supplementing with Vitamin E reduced levels of the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST), decreased blood lipid levels, and improved liver health in people with NAFLD.17

Elevated AST and ALT levels can indicate liver inflammation and damage in people with NAFLD, so lower levels are favorable.

Vitamin E May Help Manage Dysmenorrhea 

Dysmenorrhea is a condition characterized by severe and frequent menstrual pain, such as cramps and pelvic pain. Promisingly, research suggests Vitamin E rich foods and supplements may reduce pain in women with this condition.

In a 2018 study of 100 women with dysmenorrhea, taking 200 IU of Vitamin E daily relieved menstrual pain more than a placebo. The effects were even better when the vitamin was combined with an omega-3 supplement containing 180 mg of EPA and 120 mg of DHA.18

Additionally, a 2021 study showed that supplementing with a combination of Vitamin E and Vitamin C daily for 8 weeks helped reduce the severity of pelvic pain and dysmenorrhea in women with endometriosis.19

Vitamin E’s Other Potential Health Benefits

Vitamin E had also been linked to several other health benefits:

  • Vitamin E may improve lung function. Studies have shown that Vitamin E supplements could improve lung function and certain symptoms of asthma in children and adults.20
  • Vitamin E may benefit older adults. Because Vitamin E plays an important role in health, such as reducing inflammation and improving immune function, supplements may benefit people who have increased needs or don’t get enough in their diets, such as some older adults. 21
  • Vitamin E may benefit cognitive health. Maintaining optimal Vitamin E levels and taking supplements may help protect against cognitive decline, but it’s still unclear whether the supplements benefit people with cognitive conditions like Alzheimer’s disease.22

The Humanist Beauty Herban Wisdom® Facial Oil Features Vitamin E

The Herban Wisdom Facial Oil

Tocopherol plus Vitamin E rich plant extracts are integrated into the Humanist Beauty Herban Wisdom® Facial Oil for their antioxidant, anti-inflammatory, photo-protecting, and moisturizing properties. Cranberry, Coriander Seed, Cucumber Seed, and Rosehip Oil combine to defend skin from oxidative damage and bind moisture to the skin.

The Humanist Beauty Herban Wisdom® Facial Oil is non-irritating and well tolerated; it’s suitable for all skin types. It supports overall skin wellness and may assist with its healing.

You can shop the Humanist Beauty Herban Wisdom® Facial Oil here.

 

References:

https://lpi.oregonstate.edu/mic/vitamins/vitamin-E [1] [3]

https://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/#:~:text=Naturally%20occurring%20vitamin%20E%20exists,recognized%20to%20meet%20human%20requirements [2]

https://pubmed.ncbi.nlm.nih.gov/9706379/?dopt=Citation [4]

https://pubmed.ncbi.nlm.nih.gov/17256076/?dopt=Citation [5]

https://pubmed.ncbi.nlm.nih.gov/9448204/?dopt=Citation [6]

https://pubmed.ncbi.nlm.nih.gov/15675947/?dopt=Citation [7]

https://onlinelibrary.wiley.com/doi/full/10.1111/iwj.12295 [8]

https://www.nature.com/articles/s41598-020-73741-6 [9]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976416/ [10]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3789494/ [11]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5551541/ [12]

https://pubmed.ncbi.nlm.nih.gov/29891745/ [13]

https://pubmed.ncbi.nlm.nih.gov/29891745/ [14]

https://pubmed.ncbi.nlm.nih.gov/30846828/ [15]

https://pubmed.ncbi.nlm.nih.gov/31405672/ [16]

https://pubmed.ncbi.nlm.nih.gov/32810309/ [17]

https://pubmed.ncbi.nlm.nih.gov/29542390/ [18]

https://pubmed.ncbi.nlm.nih.gov/34122682/ [19]

https://pubmed.ncbi.nlm.nih.gov/24338254/ [20]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6140432/ [21]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645610/ [22]

A Look at Skincare Clays

Made from volcanic ash, and created deep within the earth as ancient-rich deposits of minerals, clay is renowned as one of the purest natural skin beautifiers in the world. It’s been celebrated for centuries, across many different cultures and civilizations, for its anti-inflammatory, purifying, and nourishing properties — and relied upon to detoxify, beautify, and refresh when applied as a facial mask since the times of Cleopatra. In this blog, we’ll explore the history using clay for skincare, why clay is used, the types of clay commonly used in skincare, and a few clean products containing clay to take note of.

The History of Using Clays for Skincare

From “band-aids” made from wet clay placed over a wound to mud baths frequented socially in ancient Rome and Greece, the topical use of clay for soothing and healing skin leaves its mark throughout ancient history. Aristotle even recommended the consumption of clay for internal medicinal uses as far back as the 4th century BCE.

Five thousand years ago in India, according to ancient Ayurvedic tradition, clay was used in the form of face and body masks as a skin treatment and during Indian religious rituals and weddings. Clay was also popular in Egyptian skincare as Cleopatra used it twice a week on her face to draw out impurities.

In ancient China, Yang Guifei, a notorious beauty and concubine of the great Tang emperor Xuanzong, often mixed pearls, jadeite, lotus root, and ginger into clay mud masks. These masks are among the first clay mud masks reported in history.

Clay has also been used by cultures spanning the Australian aboriginals, South and North American natives, and Central African tribesmen as an external and internal cleanser, known colloquially by names such as “the mud that heals.”

In more modern times, before the French Revolution, mud masking was featured in the famous health spas of Europe frequented by the rich and noble. In the 1920s, clay masks became even more popular when the first commercially-manufactured cosmetic face mask gained widespread use.

Today, backed with clinically-tested scientific proof, this ancient skin remedy remains a beauty staple and go-to detoxifier.

Science-Backed Benefits of Clay for the Skin

Clay is one of the most cleansing and detoxifying ingredients you can use on your skin. Rich in minerals, the benefits help to clear blemishes, draw out impurities, and leave you with a brighter complexion. Here’s a deeper look:

Clay Is an Anti-Bacterial

Hydrated clay binds with not just toxins but also harmful bacteria and pathogens. When hydrated clay is applied to the skin and left to dry, as in the case of a clay mask, it binds to bacteria on the surface of the skin and deep in the pores. It brings the dried-up bacteria to the surface of the skin to then be washed away.1, 2

This act reduces the overpopulation of pathogenic bacteria to friendly microflora, which is responsible for bacterial skin problems, acne, and even poison ivy. In other words, clay works as a natural antibiotic that can heal skin infections and even remedy issues like eczema, dermatitis, and psoriasis. It’s known to be even more effective than most antibiotics, as it will not entirely wipe out the colonies of friendly bacteria that promote healthy skin immunity.3, 4

Clay Can Detoxify and Purify the Skin

Clay has a strong negative electrical charge, which binds to negatively charged toxins and pulls them from the skin when used topically. Any form of an environmental pollutant, nanoparticles, cacogenic, heavy metal, chemical, and essentially any unnatural impurity you could think of – can be eliminated from the body with the use of clay.5

Clay Can Oxygenate the Cells

Clay can not only pull toxins out of the skin’s pores but also hydrogen from the skin cells, which allows more room for oxygen to benefit the skin tissues and rejuvenate them. This leads to improved circulation and overall healthier skin.

Clay Can Regulate Sebum Production

The skin naturally produces oil, known as sebum, to protect and moisturize it. When the immune system is over-activated, be it from an infection, autoimmunity, stress, or toxic overload, the skin can overproduce sebum. This overproduction can result in acne, blackheads, whiteheads, and other skin blemishes.

While treating the root cause of sebum imbalances is an internal job accomplished via diet and lifestyle, clay is an incredible remedy for oily and acne-prone skin. Clay can “soak” up excess sebum and clean out clogged pores.

Clay Can Leave Your Skin Soft, Smooth, and Glowing

Clay is loaded with an essential beautifying nutrient known as silica. This trace mineral is one of the most abundant minerals in the body; it’s responsible for manufacturing connective tissues such as the muscle, tendons, ligaments, cartilage, collagen, skin, and bone. Silica also happens to make your skin very soft and smooth.

Clay Can Rejuvenate and Regenerate the Skin

Clay can be used to rebuild damaged skin fibers as well as promote youthful skin and prevent or eliminate wrinkles. Bentonite Clay specifically has been shown to promote blood circulation to the skin, thus increasing the healing and regenerating of skin tissue. 

Clay Is Completely Natural

Many skincare products today contain very harsh ingredients. These ingredients like BPA, synthetic fragrances, parabens, phthalates, and other unnatural, toxic substances are linked to everything from chronic disease to skin irritation. Clay is a completely natural way to detoxify, cleanse, purify, exfoliate and beautify your skin without any negative side effects.

Types of Clay and Their Benefits

Depending on your skin type, one clay may be better suited for you than another. Here’s a look at a few of the most commonly used clays in skincare, along with their mineral type and specific benefits:

Bentonite Clay

Pictured: Bentonite Clay   Source: Jindeal 

Bentonite Clay is formed from the weathering of volcanic ash in seawater, which converts the natural glass present in the ash to clay minerals. It produces a negative electrical charge upon contact with fluid which bonds to the positive charge of many toxins, heavy metals, impurities, and chemicals.

Mineral Profile: Calcium, Magnesium, Iron, Copper, and Zinc

Benefits: Bentonite Clay is particularly impressive due to its ability to absorb up to 700% of its mass in water from your skin. It’s perfect for absorbing deep oils and dirt and is the best clay for oily skin types. Bentonite’s antibacterial and anti-inflammatory properties also can help heal breakouts. 

Kaolin Clay

Kaolin Clay

Pictured: Kaolin Clay  Source: Those Graces

Kaolin Clays are some of the most commonly used clays for face masks. In its purest form, it has a bright white color, though other varieties include shades of red, pink, brown, and yellow. This color change owes itself to the mineral content and where it’s from globally. 

Mineral Profile: Kaolinite, Quartz, Mica, Iron, Muscovite, Illite, and Feldspar

Benefits: Kaolin Clay is one of the best options for sensitive, dry, or acne-prone skin. White Kaolin Clay is exceptionally mild and great for absorbing oils and deep impurities without causing irritation or redness. Longer-term, routine use of Kaolin Clay can restore the skin elasticity and reduce fine lines.

Rhassoul Clay

Rhassoul Clay

Pictured: Rhassoul Clay   Source: Farnatchi Spa

Meant for oily or acne-prone skin that also suffers from mild pigmentation, the cleansing action of Rhassoul Clay can almost be described as industrial-strength. In fact, it’s often used in kitty litter and to absorb oil spills on pavements; hence the reason it’s perfect for those who suffer from excessively oily skin. 

Mineral Profile: Magnesium, Sodium, Zinc, Iron, Phosphorus, and Potassium

Benefits: Rhassoul clay draws out oils, dirt, dust, and pollutants deep within pores while reducing redness and inflammation. Long-term use can also help balance sebum production. Rich in magnesium and potassium, some studies show that the skin’s absorption of these minerals can help form a barrier to prevent breakouts.

Product Spotlight

There are an array of products on the market that utilize different clays for their benefits. From cleansers to masks to shampoo bars, the options are endless, making it easier than ever to add products formulated with clay to your regime. Here are a few to take note of:

NENA Natural Face Wash

To shop the NENA Natural Face Wash, click here

Honest Beauty Magic Gel-to-Milk Cleanser

To shop the Honest Beauty Magic Gel-to-Milk Cleanser, click here

ERIGERON All-In-One Pink Clay Shampoo Bar

To shop the ERIGERON All-In-One Pink Clay Shampoo Bar, click here

C’est Moi Mellow Marshmallow White Clay Cloud Mask

You can shop the C’est Moi Mellow Marshmallow White Clay Cloud Mask, click here

To shop the Acure Brightening Facial Scrub, click here

The Humanist Beauty Handcrafted Bar Soap Features ClayHumanist Beauty Handcrafted Bar Soap

Elevate your mood as you cleanse your skin. Humanist Beauty’s 100% vegan botanical bar soaps are artisan-crafted, essential oil-infused, and eco-conscious with no plastic wrapping or labels. While there are five different aromatherapeutic recipes to choose from, two are formulated with Kaolin Clay, Rhassoul Clay, and Bentonite Clay. 

Humanist Beauty Detox Handcrafted SoapThe Humanist Beauty Detox Handcrafted Soap is a purifying melange of crisp eucalyptus, rosemary, lemon, and activated charcoal. Formulated with Rhassoul Clay and Kaolin Clay, the Detox Soap acts as a gentle cleanser and can help absorb excess sebum, purify and detoxify pores, soothe sensitive, irritated skin, and gently exfoliate dead surface cells

Humanist Beauty Soothe Handcrafted Soap

The Humanist Beauty Soothe Handcrafted Soap can vaporize away the feeling of sore achy muscles and congestion with cooling notes of cedarwood, peppermint, balsam, and menthol. Formulated with Bentonite Clay, the Soothe Soap can help remove excess oil and toxins from the skin, address acneic conditions, gently exfoliate, and fight bacteria. 

You can shop the Humanist Beauty Handcrafted Soap here

 

References:

https://pubmed.ncbi.nlm.nih.gov/11376396/ [1]

https://pubmed.ncbi.nlm.nih.gov/9850994/ [2]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2413170/ [3]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904249/ [4]

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5632318/#:~:text=Bentonite%20clay%20has%20been%20shown,negative%20charge%20toxins%20(7). [5]