Glutathione, the master antioxidant
Date: 2015-03-09
Author: Jennifer Joseph
Access: Public

What are antioxidants, how do they work, what do they do to keep our bodies healthy and which one should you be taking?

While everyone has heard the term antioxidants used in magazine articles, news reports and even on food packaging, many of us may be confused as to their benefits.

Put simply, antioxidants are substances usually sourced from fresh fruit and vegetables, that counteract the damaging effects of “free radicals” in the body. Free radicals are highly reactive molecules which can be produced naturally by our body simply by breathing in oxygen. As the free radicals interact with other molecules in the body, they can cause oxidative damage that can impact normal liver detoxification processes.

For the most part, our body’s natural antioxidants can manage the detoxification of these free radicals. However, even when you’re trying to be your healthiest, you may face increased environmental factors and toxins that can combat the positive effects of your body’s natural antioxidants. An increase in damaging factors can occur through smoking, weight gain, pollution, stress, an unhealthy diet and even exercise; and this production of free radicals can become excessive, resulting in a need for additional antioxidants.

Which antioxidant is for me?

Boosting your antioxidant intake can help provide added protection for your body.

Nature provides us with a wide range of antioxidants, and because they are so varied, different antioxidants provide benefits to different parts of the body. 

For example, if you’re looking to keep your eye health in check, betacarotene (and other carotenoids) are beneficial; lycopene helps maintain prostate health; flavonoids are especially beneficial for heart health; and proanthocyanidins are your go-to antioxidant for urinary tract health.

Glutathione, known as the king of antioxidants, is the most abundant endogenous antioxidant that plays a pivotal role in regulating oxidative stress, detoxification and immune function.[1]

Produced by the body with precursors from the diet, glutathione is most concentrated in the liver, spleen, kidneys, intestines, lung fluid, lens, erythrocytes and leukocytes; the liver being the largest glutathione reservoir[2] where it is involved in detoxification.

Glutathione levels naturally decline with age, beginning to weaken around age 45 and declining quickly after 60 years.[3] Intense physical exercise also reduces glutathione levels in blood, muscle and the liver.[4,5]

Oxidative stressors that can deplete glutathione include: ultraviolet and other radiation; viral infections; environmental toxins, household chemicals and heavy metals; surgery, inflammation, burns, septic shock; age; intense exercise; and dietary deficiencies of GSH precursors and enzyme cofactors.[2]

It seems that even when we are trying to live a healthy lifestyle, we may be in short supply of glutathione—and that means we’re missing a critical piece of the body’s natural defense mechanism. 

As glutathione levels may be difficult to increase through the diet alone, it is more important than ever to make this powerful antioxidant part of your daily health regimen.


  1. Richie JP, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr 2014:DOI 10.1007/s00394-014-0706-z
  2. Glutathione, reduced (GSH) monograph. Alt Med Rev 2001;6(6):601-607.
  3. Vojdani A, Mumper E, Granpeesheh D, et al. Low natural killer cell cytotoxic activity in autism: the role of glutathione, IL-2 and IL-15. J Neuroimmunol 2008;205:148-154.
  4. Lang CA, Naryshkin S, Schneider DL, et al. Low blood glutathione levels in healthy aging adults. J Lab Clin Med 1992;120(5):720-725.
  5. Duthie GG, Robertson JD, Maughan RJ, et al. Blood antioxidant status and erythrocyte lipid peroxidation following distance running. Arch Biochem Biophy 1990;282(1):78-83.