Glutathione (GSH) is the most abundant endogenous antioxidant, which means the body produces it itself from cysteine, glutamic acid and glycine. Glutathione levels can drop when cysteine is in short supply, and GSH depletion has been linked to a range of detrimental conditions, from impaired immune function to increased risk of chronic disease.
The antioxidant may be destroyed in the stomach acid and suppliers have sought ways to protect it after oral consumption and ensure delivery to the intestine. A new study by scientists from Penn State University College of Medicine explored the potential of liposomes, a well-researchered drug delivery system, to boost glutathione levels in the body.
“While liposomal GSH preparations are commercially available, there have been few clinical reports on their effectiveness and no data on their ability to enhance body GSH stores,” wrote the scientists in the European Journal of Clinical Nutrition.
Results of their small study indicated that the liposomal glutathione did indeed increase GSH levels in healthy adults, with improvements also observed for immune function markers.
“The results of this pilot study demonstrate for the first time increased body stores of GSH after oral administration of liposomal GSH in humans. Liposomal GSH appeared to be effective at two doses (500 and 1000 mg/d) and the effects were seen as early as 1 week,” they wrote.
Led by Dr Raghu Sinha, an associate professor at Penn State’s Department of Biochemistry and Molecular Biology, the researchers recruited 12 healthy non-smokers aged between 50 and 80 who were not taking any antioxidant supplements, and randomly assigned them to one of two groups: A low dose (500 mg) or a high-dose (1,000 mg) liposomal glutathione regimen for four weeks. The product used in the study was Tri-Fortify Orange by Researched Nutritionals (Los Olivos, CA) which uses phosphatidylcholine liposomes. Researched Nutritionals funded the study.
Results showed that glutathione levels were increased after only one week, with maximum levels being observed after two weeks. These increases were accompanied by decreases in markers of oxidative stress, with levels of plasma 8-isoprostane falling 35% and the ratio of oxidized to reduced GSH decreasing by 20%.
Natural killer (NK) cell cytotoxicity, a measure of immune function, increased by up to 400% by two weeks, said the researchers. In addition, lymphocyte proliferation increased by up to 60% after two weeks.
“Collectively, these preliminary findings support the effectiveness of daily liposomal GSH administration at elevating stores of GSH and impacting the immune function and levels of oxidative stress,” wrote the researchers.
Dr Sinha and his co-workers noted that this was only a small pilot study that did not use a placebo control, and therefore the results cannot be generalized to other healthy or diseased populations.
“While […] we would not expect significant changes to occur in the measured study outcomes, future placebo-controlled randomized trials with liposomal GSH will be required to confirm the specificity of its intervention effects,” they concluded.
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1038/ejcn.2017.132
“Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function”
Authors: R. Sinha et al.