Glutathione is made from three amino acids: cysteine, glycine, and glutamic acid. Present in humans, animals, plants, and fungi, it helps to protect cells from environmental and chemical oxidative damage that occurs through day-to-day living. Glutathione also helps the liver to detoxify our blood and helps the body “recycle” vitamins E and C.

Studies show that higher blood levels of glutathione are associated with a reduced risk for illness, especially among the elderly. Conversely, lower blood levels of glutathione have been associated with increased risks for cancer, heart disease, diabetes, dementia, infectious diseases, and much more, according to a 2007 study. 

There are many ways to increase glutathione levels, using both diet and nutritional supplements. Consuming the following sulfur-rich foods can help optimize blood glutathione levels. 

Sulfur-rich vegetables and fruits:

• Avocado
• Broccoli
• Cabbage
• Cauliflower
• Garlic
• Grapefruit
• Kale
• Onions
• Tomatoes

Cysteine-rich foods, such as chicken, turkey, yogurt, cheese, eggs, sunflower seeds, and legumes can also help raise blood levels of glutathione. When this is not enough, the following supplements can be considered. 

NAC (N-Acetyl L-Cysteine (NAC)

N-acetyl cysteine (NAC), a potent antioxidant, is a derivative of the naturally occurring amino acid l-cysteine. Aside from using it to treat those who overdose on paracetamol (acetaminophen) and to break down mucus in the lungs, most doctors pay NAC little attention. 

NAC is the nutritional supplement normally consumed to help increase glutathione levels. When ingested, the body converts the more stable NAC to the less stable glutathione molecule. It can be taken orally once or twice per day. 

Whey Protein 

Whey protein powder is popular and frequently used as a meal replacement. It is a common supplement used by athletes and those who exercise routinely. Because it is satiating, it is also often used by those trying to lose weight. 

Whey protein is rich in branched-chain amino acids and essential amino acids, including the proteins required to make glutathione. If you drink milk or eat cheese, you probably consume whey protein regularly — the protein in cow’s milk is 20-percent whey, 80-percent casein. 

A 2020 study in Nutrition demonstrated that whey protein could improve glutathione levels for diabetics while reducing markers of oxidative damage. In addition, a 2019 study in the Journal of Wound Care using whey protein showed improved glutathione levels in test subjects.

Omega-3 Fatty Acids

Omega-3 fatty acids, also known as polyunsaturated fatty acids or PUFAs, play an important role in human health. Consisting primarily of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), they are believed to have numerous benefits for the heart, brain, gut, and joints, thanks to resolvins, active metabolites that, help reduce inflammation, according to studies.

A 2017 double-blind, placebo-controlled trial was conducted among 60 subjects with diabetes. Subjects were given 2,000 mg of EFA or a placebo. Those who took the EFA saw a decrease in inflammation (CRP) and an increase in blood glutathione levels. 

Further, a 2019 study in Phytotherapy Research showed that both omega-3 fish oil and flaxseed oil at a dose of 1,000 mg twice per day raised blood levels of glutathione.  

A 2014 study in Nutrition Journal showed that a majority of people do not consume enough essential fatty acids in their diet. However, these important nutrients can be found in a large variety of food sources, including fish (mackerel, cod, and salmon are among the richest), walnuts, chia seeds, flax seeds, hemp seeds, and avocado.

Usual dose: 1,000-2,000 mg once or twice per day. 

B Vitamins

There are eight B vitamins, and they all play important roles in overall health and in energy metabolism. They are specifically important in the metabolism of fats, carbohydrates, sugar, and proteins and help the body transform these important nutrients into usable energy. 

All B vitamins are water-soluble, which means that any unused or excess amount present in the blood is excreted in the urine. 

A 2014 study discusses the importance of vitamin B12 (also known as cyanocobalamin) and the role it plays in glutathione metabolism. Further, a vitamin B12 deficiency was associated with lower levels of glutathione in the blood, according to a 2017 study in Molecular Neurobiology. 

Suggested dose:  B-complex vitamin as directed on the label. 

Vitamin C (Ascorbic Acid) 

Essentially, all species of animals, including most mammals, can make vitamin C — exceptions are humans, monkeys, and guinea pigs. Many scientists believe that at one time the human body had the ability to make vitamin C, but lost the capacity. 

The brain and adrenal glands have the highest concentrations of vitamin C at 15 to 50 times higher than those found in the blood. With its antioxidant properties, the vitamin is also an enzyme “co-factor” in at least eight important biochemical reactions. 

A 2009 study in The American Journal of Clinical Nutrition found that over seven percent of people age six and older were vitamin C deficient when their blood was tested. More than half of those surveyed consumed low amounts of foods rich in vitamin C. I personally have diagnosed three patients with scurvy, a disease that was diagnosed in British sailors in the 1800s, who had limited access to fresh fruit.  

A 1993 study evaluated the effect of 500 mg to    2,000 mg of vitamin C on red blood cell (RBC) glutathione levels. Researchers found that 500 mg was sufficient to raise glutathione levels in RBC and that a dose of  2000 mg per day was no more efficient than 500 mg per day. 

A 2000 study showed the levels of vitamin C in the blood were correlated with glutathione levels in white blood cells. White blood cells help protect against infection. 

Lastly, a 2003 study evaluated the effect of vitamin C supplementation in healthy adults. Half the test subjects in the study were given 500 to 1000 mg of vitamin C while the other half were given a placebo pill.  After three months, those who supplemented with vitamin C had higher levels of glutathione in their white blood cells than those who took a placebo pill.

Suggested dose: 500 to 1,000 mg once or twice per day.

Vitamin E

Vitamin E is a potent antioxidant with numerous health benefits. Supplementation with vitamin E, even in the form of a multivitamin, can help optimize blood glutathione. A 2013 study showed that those given a vitamin E supplement had increased blood levels of glutathione compared to those who took a placebo.  Suggested dose: As directed on the label.  

Alpha Lipoic Acid (ALA)

Alpha lipoic acid is a naturally occurring compound made by the human body. It is also a potent antioxidant. 

A 2016 study demonstrated that a food supplement which contained alpha lipoic acid could help improve glutathione levels while reducing overall oxidative damage. 

A 2019 study of diabetics also confirmed that ALA could help increase blood glutathione levels in those with diabetes. 

Selenium

A trace mineral with important functions in overall health, selenium plays a role in immunity, reproduction,   and anti-oxidation. Food sources of selenium include beef, chicken, brazil nuts, sunflower seeds, chia seeds, and mushrooms. 

Selenium is overall considered safe and can be taken as an individual supplement or in the form of a quality multivitamin.

Probiotics

Probiotics are commonly consumed for intestinal health. However, they also appear to help support healthy cellular levels of glutathione. A 2013 study in patients with diabetes showed that a diverse probiotic supplement that contained lactobacillus, bifidobacteria, and streptococcus thermophilus could help raise blood levels of glutathione. Suggested dose: 5 billion to 60 billion units once or twice per day.

Green Tea

Excluding water, green tea is the second most common beverage consumed worldwide, second only to coffee.   A 2013 study shows that green tea consumption (four cups per day or more) increased blood glutathione levels in test subjects when compared to those who only drank water (four cups per day). Green tea extract is also available in a supplement.

Other Herbs Which Increase Glutathione

Other herbs which have been shown to increase blood glutathione levels include the following:

• Turmeric
• Milk thistle
• Ginkgo biloba