Glutathione - the Master Antioxidant
Glutathione is the most abundant antioxidant in the body. Chemically, it is a very small molecule that is made within the body itself. It is considered to be an important antioxidant because it is located inside every cell in the body. In general, antioxidants, the most well-known of which are vitamins C and E, are important for health because they neutralize harmful free radicals which can build up in cells and cause damage. Along with its own antioxidant actions, glutathione recycles vitamin C and other antioxidants. It also helps the liver remove foreign chemicals such as drugs and toxins. It has widespread health benefits because it is present in immune cells and drives the functions of the immune system, whose job is to fight off disease and infections.
Food sources that either contain glutathione or its precursors to help the body produce more include broccoli, Brussels sprouts, cabbage, cauliflower, avocados, peaches, watermelon, cinnamon, cardamom, turmeric, tomatoes, peas, garlic, onions, red peppers as well as meat, fish and green leafy vegetables. Clearly, people who consume a varied, healthy diet get enough glutathione from their diet. On the other hand, those with poor diets may not get enough glutathione. Sufficient levels of selenium, a micronutrient found in meat, seafood, egg yolks and certain plants, and alpha-lipoic acid, another antioxidant, are both necessary to maintain glutathione levels. Glutathione production increases during exercise. However, strenuous exercise, alcohol, and drugs such as acetaminophen, deplete glutathione from the liver.
Glutathione performs many important roles in the body, including:
- Managing cell growth and division
- DNA synthesis and repair - protecting DNA when it’s being made and repairing damaged DNA
- Protein function - helping to maintain proteins in their active, functional forms
- Amino acid transport - moving many substances, including amino acids, in and out of cells as needed
- Enzyme activation and catalysis - helping enzymes transform into their active state and increasing the efficiency with which they function
- Detoxification - breaking down toxins in the liver. The enzyme glutathione S-transferase binds to toxins such as carcinogens, heavy metals, herbicides and pesticides and makes them water-soluble, so that they can be removed from the body as bile, sweat and urine. Glutathione-related enzymes also detoxify cancer-causing chemicals so that they can be eliminated without damaging the cell or DNA.
Our body is constantly under attack from harmful chemicals called ‘free radicals’ created by a process known as ‘oxidative stress’. Some free radicals are generated externally, while others are made in the body itself. When they come in contact with DNA or other cellular components, free radicals attack the nearest stable molecule and ‘steal’ its electron. A molecule that loses an electron then becomes a free radical itself and attacks the next nearest stable molecule, thus setting off a chain reaction that can potentially cascade through hundreds of molecules. Glutathione performs a vital role in repairing damaged DNA by replacing missing electrons.
Glutathione can exist either in so-called ‘reduced’ or ‘oxidized’ states. In healthy cells and tissue, more than 90% of total glutathione is in the reduced form. An increased ratio of the oxidized-to-reduced-forms is considered to be a significant marker of oxidative stress and is used to assess cellular toxicity. Oxidative stress in blood vessels is associated with many diseases. Glutathione manages the cell’s oxidative stress response.
People who have cancer, AIDS, cancer and other very serious diseases are almost invariably found to be depleted in glutathione. Although the reasons for this are not completely understood, it is clear that glutathione is extremely important for maintaining intracellular health. Laboratory studies have shown that glutathione has the potential to help fight almost any disease, particularly those associated with aging, since free radical damage is believed to be one of the major underlying causes of many of the diseases associated with old age. The body’s immune and detoxification systems cannot function without glutathione, which is an essential part of staying young, active and healthy. Within the immune system itself, glutathione enhances the activity of immune cells and also functions as an antioxidant within them. Some health experts believe that raising and maintaining glutathione levels can help minimize the risk of diseases.
There is extensive evidence that antioxidants play a protective role in cardiovascular disease, a chronic disease that is worsened by oxidative stress and inflammation. Long-term, large-scale, population-based studies have found that higher levels of glutathione, as well as vitamin E, vitamin C, and carotenoids, are associated with a lower risk of cardiovascular disease. However, results from large clinical trials do not support long-term use of single antioxidant supplements for prevention of cardiovascular disease, due to their null or even adverse effects. Overall diet quality rather than single nutrients have been shown to have protective effects.
Glutathione has been shown to increase energy levels, strength and endurance. Our energy levels are a result of many factors, including the biochemical reactions taking place within cellular mitochondria. Glutathione ensures that mitochondria remain fully charged. Clinical trials have shown that lowered or depleted glutathione in the mitochondria leads to cell death, suggesting that proper glutathione levels are vital for cellular and overall health.
While there are many strong arguments in favor of a therapeutic use of glutathione, the actual amount of research on glutathione as a supplement is very limited. Health experts disagree on who should take glutathione or its precursors. Some say everyone should take it in order to optimize overall health. Others say it should be reserved for people with cancer, or those who eat poorly and are thus unlikely to be getting much glutathione or its precursors in their diet. However, everyone agrees that people with severe diseases known to be associated with low glutathione levels, such as AIDS, heart disease and cancer are likely to benefit from glutathione supplements.