The big controversy with glutathione supplementation has been whether taking glutathione orally is absorbed and effectively raises glutathione levels. New research has now firmly established that it is able to produce these benefits. The latest study demonstrates impressive results in improving liver health.
Background Data
Glutathione's benefits can be divided into four vitally important functions:
- Antioxidant. Glutathione is not only the major antioxidant produced by the cell, it is also critical to the recycling and proper utilization of other antioxidants such as vitamins C and E.
- Critical to cellular function. Glutathione is required for the manufacture of many cellular proteins, the synthesis and repair of DNA, and the activation and regulation of cellular enzymes involved in overall cell function.
- Detoxifying compound. Glutathione is the body's most effective detoxifying agent. Glutathione binds undesirable toxins, pollutants, cancer-causing chemicals, heavy metals, and drug metabolites and excretes them through the urine or the gut.
- Immune system effects. Glutathione is critical in modulating the immune system. It boosts functions with the immune system is underactive and brings it back into balance when it is overactive.
Low levels of glutathione are linked to almost every chronic disease, especially those associated with aging like cognitive decline. Glutathione levels tend to drop as we age, as well as when we are exposed to toxins, drugs, environmental pollution and any other compound that causes oxidative damage. Even something as simple as taking acetaminophen (e.g., Tylenol) can cause glutathione levels to plummet.
Diet can contribute to raise glutathione levels to an extent. A healthy diet rich in fresh fruit and vegetables may provide about 150 mg of glutathione per day. Asparagus, avocado, and walnuts are particularly rich dietary sources of glutathione.
Prior to recent studies, there was some controversy with glutathione as a dietary supplement because it was thought that glutathione may not be absorbed when taken orally. One study is often cited to show lack of absorption. In the study, a single dose of 3,000 mg of glutathione failed to increase glutathione levels in the blood. However, it turns out there is another reason. Researchers were looking for free glutathione levels and because glutathione is so valuable it is quickly bound to transport proteins to carry to cells. That is why it did not show up as free glutathione in the blood.
The first study showing significant oral absorption was conducted at Kyoto University in 2014. The study was different because it looked not only at free, unbound glutathione in the blood, but also the level of glutathione bound to protein. The results showed that while there was no significant difference in free glutathione levels, the level of glutathione bound to protein increased significantly after glutathione supplementation. This study was groundbreaking because it explained the shortcomings of previous absorption studies.
The next study, conducted at Penn State University published in 2015 in the European Journal of Nutrition, showed again quite clearly that glutathione is absorbed orally and increases the tissue concentration of glutathione. A total of 54 healthy, non-smoking adults were randomized to placebo or oral glutathione at a dosage of 250mg or 1000mg per day for 6 months. The results showed that glutathione levels increased significantly from baseline in whole blood and red blood cells at 3 months and 6 months at both dosages. After 6 months, taking 250 mg glutathione per day increased glutathione levels by 17% in whole blood and by 29% in red blood cells. Taking 1,000 mg glutathione per day increased glutathione levels by 31% in whole blood and by 35% in red blood cells. Even more impressive was that glutathione levels increased by 250% in the cells that line the inner cheek in the 1,000 mg per day group.
New Data
There is a growing epidemic in the United States of people suffering from non-alcoholic fatty liver disease (NAFLD). It has become a source of serious concern. When the liver is damaged, it leads to the depositing of fat within the liver. This process typically occurs with liver damage caused by alcohol, but with NAFLD it is tightly linked with obesity and insulin resistance. NAFLD ranges in severity from a rather benign impairment to an inflammation of the liver called non-alcoholic steatohepatitis (NASH), which may advance to cirrhosis and eventually liver failure. NAFLD is thought to affect roughly 20-30% of Americans and NASH affects roughly 2-3%.
In a recent multi-center clinical study, the oral administration of glutathione (tradename Optitac) was shown to be effective against the onset and progression of NAFLD. In the study, 31 subjects with NAFLD were administered 300 mg daily of Optitac glutathione over a period of four months. Each subject was evaluated before and after using a process known as transient elastography with the aid of ultrasound to quantify the amount of fatty deposits and fibrosis of the liver. In addition, a variety of laboratory assessments of liver function were also performed.
Results showed that fatty infiltration of the liver was significantly improved as were blood measurements of liver enzymes, LDL cholesterol, triglycerides, free fatty acids, and ferritin levels.
Researchers concluded that the major clinical parameters and transient elastography were significantly improved by the treatment with glutathione. The hope is that this pilot study will lead to a large-scale clinical trial in future.
Commentary
This new study utilized Optitac, a reduced form of L-glutathione produced by Kohjin Life Sciences, Tokyo. It is produced naturally by a fermentation process from torula yeast. Optitac has been qualified for Generally Recognized As Safe status by the U.S. Food and Drug Administration (U.S. FDA GRAS notified GRN000293).
Reference
Kessoku T, Sumida Y, Imajo K, et al. Efficacy of Glutathione for the Treatment of Non-Alcoholic Fatty Liver Disease: An Open-Label, Multicenter, Prospective Study. J Hepatology 2016;64(2):S500.
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