Glutathione is the most important pleiotropic antioxidant in mammalian tissues (mainly synthesized by glutamic acid, cysteine and glycine), often known as the antioxidant master.
What is glutathione? Why is it interesting?
In the human body, glutathione mainly plays the role of fighting free radicals, detoxifying exogenous substances, reducing vitamin C, protecting DNA, regulating cell proliferation and apoptosis, regulating immune function and fibrogenesis, etc., and its work is far better than that of general antioxidants.
Imbalance of glutathione is often associated with a variety of diseases, such as cancer, aging, cystic fibrosis, cardiovascular, inflammatory, immune, metabolic, and neurodegenerative diseases. Note 8
What are the recommended benefits of glutathione?
1. Beneficial immune function
The immune system is a complex combination of fine cells that protect the body from infectious pathogens (bacteria, viruses, fungi, parasites) and other harmful substances in the environment.
Once the immune function deteriorates, it will produce a poor response to the vaccine, an increase in autologous antigens, and a gradual loss of the ability to recognize foreign antigens, increasing the probability of infection and chronic diseases.
A preliminary clinical study (4-week study of 12 healthy adults) showed that taking the lipid form of liposomal GSH increased glutathione levels in the blood and cells, as well as reduced oxidative stress and increased immune performance (lymphocytes and natural killer cells). Note 1
Another controlled study (4 months, 36 postmenopausal women) showed that oral administration of acetylcysteine/N-acetylcysteine (NAC) can increase glutathione levels in white blood cells and achieve the effect of strengthening immune function. Note 2
*Conclusion: Increasing glutathione levels can increase antioxidant capacity and improve immune function, but it is still to be confirmed due to the number of samples
2. Beneficial non-alcoholic fatty liver
Nonalcoholic fatty liver disease refers to non-alcohol, drug or genetic diseases of liver metabolism, mainly related to eating habits and sedentary lifestyle, with a prevalence of about 20%–30% in Western countries
In addition to causing liver inflammation, non-alcoholic fatty liver disease also greatly increases the incidence of type 2 diabetes and cardiovascular disease
One study (4-month study of 34 patients with nonalcoholic fatty liver disease) showed that oral glutathione helped reduce alanine aminotransferase (ALT, liver function index), decay parameter control (CAP, degree of liver fat accumulation), free fatty acids, and ferritin levels. Note 3
*Conclusion: Oral glutathione may be of positive help in improving liver function and fatty liver, but the results still need to be further confirmed by large-scale clinical trials
3. Reduce the incidence of atrial fibrillation after cardiac surgery
Atrial fibrillation is a common complication after heart surgery, occurring from 10% to 65% depending on the type of surgery (especially valve surgery and coronary artery bypass grafting), significantly increasing the risk of length of hospital stay, stroke, and death.
A meta-analysis (10 randomized controlled trials with 1026 participants) showed that prophylactic use of the glutathione precursor molecule, N-acetylcysteine, helped reduce post-operative atrial fibrillation events and all-cause mortality after cardiac surgery by 44% and 60%, respectively, compared with the control group (However, there was no difference in overall length of hospital stay). Note 4
*Conclusion: The use of glutathione precursor molecule: acetylcysteine (N-acetylcysteine) can reduce the probability of postoperative atrial fibrillation and all-cause mortality in adult patients
4. Cystic Fibrosis
Cystic fibrosis is an autosomal recessive disorder caused by variants in the CFTR gene.
Common symptoms of cystic fibrosis are abnormally thick secretions in the respiratory tract and pancreatic ducts, resulting in obstruction, inflammation, tissue damage and even organ decay, of which obstructive pulmonary disease is the most fatal, and other diseases such as sweat glands, hepatobiliary ducts, male reproductive system and intestines may also be affected.
A randomized, double-blind Phase II clinical study (24 weeks in 70 patients with cystic fibrosis) noted that oral glutathione precursor molecule: acetylcysteine (N-acetylcysteine) maintained or slightly improved lung function compared with placebo. Note 5
Another randomized, double-blind controlled study (24 weeks, 70 patients with cystic fibrosis) showed that oral reduced L-glutathione improved growth status (e.g., weight, height, BMI) and intestinal inflammation. Note 6
*Conclusion: Glutathione or its precursor N-acetylcysteine may have a positive effect on cystic fibrosis
5. Beneficial for exercise muscle soreness
Post-exercise muscle soreness usually occurs 6 to 12 hours after eccentric exercise, with stiffness and loss of strength due to muscle edema, and gradually resolves after about 5 to 7 days.
A controlled study (14 days, 29 men) showed that supplementation with the glutathione precursor molecule, acetylcysteine, helped combat motile muscle soreness and partially inhibited pro-inflammatory hormones. Note 7
Are there any side effects of glutathione?
Glutathione is a relatively safe supplement for most adults, and according to currently available studies, there are no significant side effects of short-term moderate use (but the safety of long-term use is still unknown), and possible side effects that have been reported include flatulence, loose stools, and skin flushing.
Safety precautions
1. Do not use pregnant women, nursing mothers, children, liver and kidney function (due to unknown related safety)
2. Glutathione may increase the skin’s sensitivity to light because it has the effect of inhibiting the formation of melanin
3. Do not use for patients suffering from allergic rhinitis or asthma (as it may worsen symptoms)
4. Some products contain additional additives and preservatives, which may cause allergies and other symptoms, please read the product label carefully before use
Does additional glutathione supplementation work?
Glutathione is made up primarily of protein in food, and some have suggested that additional glutathione supplements do not effectively raise concentrations in cells or tissues.
In this regard, a randomized, double-blind, placebo-controlled trial (6-month trial of 54 non-smoking adults) showed that daily glutathione supplementation did increase the amount of stores in human tissues, and the increase was positively correlated with dose and duration of use. Note 9