Glutathione: How to Boost Your Levels of this Critical AntioxidantPrint
Have you ever heard of glutathione? If not, I’d suggest you educate yourself on this important antioxidant. This natural antioxidant is protective from damage and regulates many important functions, including cell proliferation and apoptosis (death). It is, in fact, our cells’ most abundant antioxidant. Glutathione also assists in the synthesis of genetic material and proteins and activates gene expression.
While glutathione is obviously needed for many vital life functions, there are few ways to accurately measure intra-cellular glutathione levels. Baylor University College of Medicine researchers recently developed a fluorescent probe—called the RealThiol—that measures real-time changes in glutathione concentration in living cells, giving scientists another window to investigate the antioxidant’s role in aging, health and diseases such as cancer, Alzheimer's and Parkinson's, among others.
But can we do anything in the interim while we wait for this new technology to become widely available? How can we maintain healthy levels of this critical antioxidant, the principal compound for detoxifying environmental stresses, air pollutants, heavy metals, pharmaceuticals and many other toxic insults, but which also declines with age, setting the stage for any number of age-related health problems?
Supporting Glutathione Production
Turns out a new study, published in the peer-reviewed journal Redox Biology, may yield some answers. It seems a compound called N-acetyl-cysteine (NAC)—an altered form of the amino acid cysteine used in supplements—can help increase glutathione levels. Amino acids are the building blocks of proteins and our bodies convert NAC to cysteine, and then to glutathione.
N-acetyl cysteine has dozens of medical applications. It’s used, among other things, to counteract acetaminophen (Tylenol) and CO2 poisoning, to treat chest pain and bile duct blockage in infants, and as therapy for amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease. It’s currently used in cases of emergency medical detoxification such as the ingestion of toxic levels of heavy metals. The researchers found that at much lower levels, NAC might help maintain glutathione levels, preventing any number of age-associated metabolic declines. The study findings shed some insights into why animal health declines with age, but specifically points to a compound—NAC—that might help prevent some of the toxic processes involved.
It’s the decline of these detoxification pathways that might trigger cardiovascular disease, diabetes and cancer, among many others. The study helped highlight how cells from younger animals are far more resistant to stress than those from older animals. In young animal cells, stress doesn't cause such a quick glutathione loss. Older animal cells subjected to stress, on the other hand, quickly lost glutathione and died twice as fast. Turns out that pre-treatment with NAC increased glutathione levels in the older cells, largely offsetting stress’ effects.
In this study, scientists tried to identify the resistance the young cells’ toxin resistance, compared to those of older cells. Under stress, the younger cells lost significantly less of their glutathione than did older cells, never dropping to below 35 percent of their initial level, whereas in older cells, glutathione levels plummeted to 10 percent of their original level.
NAC, the researchers said, can boost glutathione’s metabolic function and increase its rate of synthesis. NAC is considered safe, even at extremely high levels, explaining why a low dose might be helpful for maintaining glutathione levels and improving health.
Food Sources of Cysteine
The next obvious question, of course, is how can we safely add NAC to our daily regimen? Though NAC is not found naturally in food sources, cysteine, along with the other ten essential amino acids, is present in most high protein foods. However, it requires the essential amino acid methionine to facilitate the conversion to NAC, explaining why cysteine is considered an essential amino acid as well. Pork, chicken, sausage, turkey, duck, fish, ricotta cheese, cottage cheese, yogurt and eggs all contain cysteine. Granola, oat flakes, broccoli, red pepper and onion are significant, meatless cysteine sources, along with garlic, soy beans, linseed and wheat germ.
If you don’t feel you’re getting enough dietary cysteine, NAC is available in supplement form. There is also some data showing that mixtures of various herbs, such as Ashwagandha, Bucopa, milk thistle, green tea, and curcumin can "induce” glutathione production. Remember, it’s always a good idea to first consult with a qualified healthcare professional! Anything powerful enough to heal is also powerful enough to harm. Too much cysteine and methionine can cause health problems. A 2009 Temple University study found an association between methionine levels and Alzheimer’s disease in animal models. NAC may also raise another amino acid associated with heart disease.
The Bottom Line
The study findings are a welcome development. Overall, taking glutathione or its precursors like NAC in reasonable amounts appears to be quite safe. I’m optimistic there could be a major role for NAC in preventive medicine as well, where it’s used as a prophylactic instead of an intervention to increase glutathione levels and prevent the increased toxicity we all face with aging.
(Author: Stewart Lonky, M.D.)