What does glutathione do?
Glutathione is probably one of the greatest heroes among your body's peptides. Its protective functions are so essential that your life would look very different without it.
Drugs would be more toxic, aging would start earlier and we would probably think twice about spending time in the sun.
Despite all that barely anybody has ever heard of glutathione.
In a nutshell
Glutathione is a small protein - or peptide - consisting of the three amino acids cysteine, glutamic acid, and glycine. It is produced in our liver cells and then distributed to all tissues and cells in the body.
One of its most important tasks is to scavenge free radicals and peroxides that are naturally produced in our metabolism. It can also minimize harmful oxidation caused by external factors such as solar radiation, smoking, and inflammation. Finally, it plays an important role in detoxification processes.
Oxidative stress is mainly caused by reactive oxygen radicals (ROS), which are produced during cellular energy production in the mitochondria. These radicals are produced constantly, thus, the body has a defense system that neutralizes them consisting of multiple enzymes and molecules.
However, when stress exceeds a natural and healthy amount, proteins, lipids, and DNA can be damaged. When this happens, our metabolism does not run as smoothly.
- Premature cellular aging
How can oxidation increase?
External factors: radiation, drugs, smoking, alcohol, not enough sleep
Internal factors: aging, inflammation, infections
Fruit and vegetables activate radical scavenging
Many secondary substances that are just as important for our health as the vitamins and minerals that are found in "healthy foods." Most of these substances belong to the polyphenol group have antioxidant properties that ensure reactive molecules are neutralized.
Another reason why these substances are good for us is that they are likely to trigger our body's own antioxidant machinery1, which may be able to deal with the dangers of oxidation even more efficiently than plant substances.
Glutathione is a central oxidation switch
Small sulfur-containing proteins such as glutathione, thioredoxin, glutaredoxin, and peroxiredoxin take over the majority of the body's antioxidation and protect us from their negative, disease-causing consequences.
Glutathione is produced by the enzymes γ-glutamylcysteine synthetase and glutathione synthetase in the liver. In general, it occurs in two opposite states, the "reduced" and "oxidized" form. However, "reduced“ does not mean that it is incomplete.
"Reduced“ refers to the ability of the molecule to balance oxidants by being oxidized itself. Oxidized glutathione can then be converted back to the reduced - "active" - state by another enzyme called glutathione reductase.
In this way, it acts as a switch in our cells controlling reduction/oxidation (redox) balance.
Glutathione as a health indicator
The status of oxidative stress can be determined by the ratio of reduced (GSH) and oxidized glutathione (GSSG). This ratio has already been proposed as a clinical marker to better assess the course of some diseases in which oxidation plays a role.
In general, in chronic diseases of the urinary, digestive or cardiovascular system, glutathione concentration is significantly reduced2.
Glutathione and detox?
Glutathione helps in the detoxification of xenobiotics. These are substances that are foreign to the body, usually because they are artificially produced drugs.
The body has no way to break them down. Luckily, glutathione can bind them during the process of biotransformation and ensure that they are excreted.
Helping the immune system
Reduced glutathione is also of great importance for the immune system. It helps in the activation of T-lymphocytes and other white blood cells, which are actively involved in the defense against pathogens.
The peptide is also involved in the production of cytokines. These signaling molecules ensure efficient communication between immune cells and thus a defense system that is armed against attacks.
Supplementing cysteine can boost glutathione synthesis in the elderly
Older people usually have lower glutathione levels. A study published in the American Journal of Clinical Nutrition3 examined the effect of glutathione building blocks (cysteine and glycine) on a group of 60 to 75 year-olds.
The aim was to find out whether the increased oxidative stress and reduced glutathione synthesis in older people can be compensated for by dietary supplementation with cysteine and glycine.
A 14-day supplementation was able to increase the cellular glutathione concentration, which was overall comparable to the concentration in the younger control group. A reduction in oxidative stress, which increases with age, was also observed.
Can you naturally increase glutathione activity?
- A sufficient supply of protein can guarantee that enough new glutathione is produced. Additional intake of the precursor's cysteine, glycine, and glutamic acid can also help to boost synthesis.
- Make sure to consume enough sulfur-rich foods. This includes, for example, beef, fish, poultry but also broccoli, brussel sprouts, cauliflower, and kale. Vegetables from the Allium family such as onions, shallots or garlic are also good sources of sulfur.
- Do not give your radical defense system a harder time than necessary! A healthy lifestyle ensures that scavengers like glutathione can take care of the really important things. Sufficient sleep, a low psychological stress level, a balanced diet, low alcohol consumption and the like ensure that glutathione concentrates on what it does best: keeping your metabolism in perfect balance.
The bottom line
Glutathione is an important antioxidant in our body. While our bodies produce this peptide on our own, research shows that when we experience an excessive amount of oxidative stress from natural processes (like aging) or external factors (like pollution and diet), glutathione can help keep up healthy and thriving.
 Jan Ø Moskaug, Harald Carlsen, Mari CW Myhrstad, Rune Blomhoff, Polyphenols and glutathione synthesis regulation, The American Journal of Clinical Nutrition, Volume 81, Issue 1, January 2005, Pages 277S–283S, https://doi.org/10.1093/ajcn/81.1.277S.
 Lang CA, Mills BJ, Mastropaolo W, Liu MC. Blood glutathione decreases in chronic diseases. J Lab Clin Med 2000;135:402–5.
 McCarty, Mark F, and James J DiNicolantonio. “An increased need for dietary cysteine in support of glutathione synthesis may underlie the increased risk for mortality associated with low protein intake in the elderly.” Age (Dordrecht, Netherlands) vol. 37,5 (2015): 96. doi:10.1007/s11357-015-9823-8.