What does Glutathione do for the body

Glutathione (GSH) is a tripeptide compound containing a sulfhydryl group,consisting of glutamic acid,cysteine, and glycine.Among them,cysteine?is the rate-limiting substance for the production of glutathione. Sufficient supplementation Cysteine?helps increase the body's glutathione.Glutathione has important physiological activities in the human body,such as activating the redox system,activating thiolase, and detoxifying.Widely distributed in various organs of the human body, it mainly plays a role in maintaining the biological function of cells and protecting the integrity of cell membranes.It is clinically used in the treatment and adjuvant treatment of various diseases, including chemotherapy patients, radiation therapy patients, various hypoxemia, liver diseases, drug toxicity,etc.Glutathione is an important antioxidant in cells.During oxidative phosphorylation in the mitochondria of cells,the respiratory chain of the ATP production process leaks electrons to form the free radical ROS.Cells have their own antioxidants,including superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT). Glutathione is the figure below (appeared and analyzed in "Autoimmune Thyroiditis (Part II): Hashimoto's Can Supplement Inositol and Selenium, Various Auxiliary Nutrients", and it will be analyzed again here), which simplifies the removal of ROS free radicals in cells. In the process, when the superoxide of free radicals appears, the first pass is SOD, which converts superoxide into less toxic hydrogen peroxide (H2O2), and then GPx (with glutathione as a substrate) and CAT The hydrogen peroxide is then converted into harmless oxygen and water molecules.This is the antioxidant process that neutralizes free radicals in cells.Glutathione is continuously oxidized and reduced in cells,and reduced glutathione (GSH) is converted into oxidized glutathione (GSSG) after producing antioxidant effects in cells. 

GSH is oxidized under the enzymatic action of glutathione peroxidase (GPx), while neutralizing free radical H2O2 to form harmless water and oxygen molecules.While GSSG is rapidly reduced to GSH under the action of glutathione reductase (GR),the ratio of GSH/GSSG in cells shows the oxidative stress state of cells.Since too much GSSG is cytotoxic,the GSSG that cannot be reduced rapidly is sent out. cells, causing the reduction of glutathione in the cells, and increasing the reduced glutathione in the cells helps reduce oxidative stress.Oxidative stress is the result of an imbalance between the production and scavenging of oxygen free radicals in cells,leading to human aging and metabolic diseases, autoimmune diseases and mental health problems.Glutathione cooperates with other antioxidants to achieve antioxidant effects.For example, vitamin E neutralizes lipid oxides, and oxidized vitamin E is reduced by vitamin C,while glutathione reduces and oxidizes vitamin C,making vitamin C And vitamin E can be recycled to produce antioxidant effects.While increasing vitamin C and vitamin E cannot directly increase GSH, they can share the antioxidant effect of glutathione,increase the ratio of GSH/GSSG,and reduce oxidative stress.

Direct glutathione supplementation

Although glutathione is widely present in cells, the effect of oral glutathione is not ideal.There are ¦Ã-glutamyl transpeptidase (GGT) in the liver and cells.GGT can degrade glutathione.GGT degrades glutathione outside the cell and provides a substrate for the production of reduced glutathione in the cell ( Cysteine), so whether it is oral or injected glutathione,it will inevitably be "killed" by GGT outside the cell, and there is not much GSH left in "survival".Oral GSH will be hydrolyzed in the intestine.As early as 1992, a clinical study has found that a one-time oral 3g glutathione does not increase the body's glutathione level.A single time is ineffective, how about supplementing it every day? In 2011, there has been a double-blind control group to test whether oral glutathione can increase the concentration of glutathione in cells.40 healthy subjects were supplemented with 500mg x 2 of glutathione per day for 4 consecutive weeks.The results showed that the subjects After the test period,oxidative stress did not improve,neither reduced glutathione nor oxidized glutathione changed in the subjects, and the study concluded that oral glutathione had little effect on healthy adults.

4 weeks doesn't work, what about 6 months? In a double-blind control clinical study published in 2015, 61 healthy subjects were divided into 3 groups to receive the test, and the two intervention groups were respectively orally supplemented with 250 mg or 1 g of glutathione per day for 6 consecutive months. The results showed that supplementing 250mg per day did not change the glutathione in blood and cells during the test period, while supplementing 1g per day increased glutathione levels in blood and cells.It is worth noting that although it is 1g a day,oral glutathione does not seem to reach saturation after 6 months of supplementation,indicating that the effect of glutathione supplementation is not only proportional to the time of supplementation,but the effect may take longer. time produces.

Whitening effect of glutathione

Many people are concerned about whether glutathione can whiten or not. A meta-analysis published in 2019, including five clinical studies,found that glutathione improved melanin markers in uncovered skin,but not in sun-exposed skin.So glutathione still has a certain effect on tanning-related whitening.Looking at the specific clinical research, a double-blind control group clinical study published in 2012,60 subjects were tested,the intervention group took 500 mg of glutathione per day,and the melanin index of the intervention group was significantly reduced after 4 weeks.The conclusion of the study is that oral administration Glutathione may have a whitening effect in some subjects.Is injectable glutathione more effective than oral glutathione? In a controlled clinical study published in 2016, 32 female subjects aged 25 to 47 completed the trial,and the intervention group received an intravenous infusion of glutathione (1.2 g) and vitamin C twice a week for 6 weeks After the trial period, 37.5% of the subjects in the intervention group improved significantly, and 18.7% of the subjects improved but not better than the control group. After stopping glutathione, the whitening effect gradually disappeared, and after 6 months, only The next subject also maintained the whitening effect. Notably, 8 of the subjects (50 subjects enrolled) developed liver dysfunction after receiving the glutathione intervention and had to discontinue the trial. Intravenous glutathione is not safe.

Glutathione precursors and other nutrients

NAC (N-Acetyl Cysteine) is an effective way to supplement glutathione. After oral administration of NAC, NAC is absorbed through the intestinal tract and metabolized in the liver to produce cysteine, which is the rate-limiting substrate of glutathione. Unless liver function is impaired, NAC supplementation can effectively increase the body's glutathione Peptide levels.Excessive exercise can cause oxidative stress to the body and reduce glutathione levels in the body. In a double-blind control group clinical study published in 2018, the subjects were divided into 3 groups according to the level of glutathione in the body. The subjects were supplemented with 600mg x 2 of NAC every day for 30 consecutive days. After the test period, it was found that NAC could increase glutathione, but only for the subjects in the low-level glutathione group.The conclusion of the study is that NAC can increase glutathione levels in people deficient in glutathione, and achieve the effect of reducing oxidative stress.In addition to glutathione precursors, supplementation with NAD+ precursors can also increase glutathione levels.A controlled clinical study in 2020 found that NR supplementation with an NAD+ premise increased glutathione levels in subjects.The trial, which involved two groups of subjects, young and old, found that older adults had higher oxidative stress and lower glutathione levels, and that NAD levels were significantly higher in both young and older adults after NR supplementation, but Only the elderly increased glutathione, only the elderly showed a significant reduction in oxidative stress, and little help in the young.The conclusion of the study is that NR may only help people who are deficient in antioxidants.

Glutathione and Anti-Aging

In addition to glutathione having a certain effect in whitening,glutathione can also improve skin aging.In a double-blind control clinical trial in 2017, the intervention group was supplemented with 250mg of reduced glutathione (GSH) per day, and In the same dose of oxidized glutathione (GSSG) group,after 12 weeks of the trial period,it was found that both GSH and GSSG could improve the skin condition of the intervention group.Compared with the control group, all subjects had less UV-induced dark spots, and some After subjects were charged with glutathione, skin wrinkles were reduced and elasticity was increased.People with HIV experience premature aging, which results in states of aging, including cognitive decline,even in young adults. In a clinical study published in 2020, HIV patients were supplemented with glutathione precursors:NAC and glycine for 12 consecutive weeks. After the trial period,the subjects' glutathione levels increased and the symptoms of cognitive deterioration improved.