Stanford Report, October 4, 2000
|Dietary supplement helps to keep immune system
BY KRISTIN WEIDENBACH
Stanford researchers have found that giving patients who are infected with the human immunodeficiency virus (HIV) a daily dose of a dietary supplement can boost their levels of glutathione a nutrient essential for proper functioning of the immune system. Restoring glutathione levels to those found in healthy people may help HIV-infected patients fight the AIDS-causing virus and fend off other diseases.
"The importance here is that glutathione is a central component of all cells, and glutathione deficiency is associated with poor prognosis in many, many diseases," said Leonore (Lee) Herzenberg, PhD, professor of genetics. She is senior author of a paper describing the new study, published in the October 1 issue of the European Journal of Clinical Investigation.
Lee Herzenberg and her colleagues conducted a clinical trial in which 31 HIV-infected patients were given daily doses of N-acetylcysteine (NAC) a substance that is turned into glutathione in the body. Thirty others were given a benign sugar pill. At the start of the trial all patients had glutathione deficiency some patients had only half the amount found in healthy people. At the end of the two-month trial, those taking NAC had increased the amount of glutathione in their bodies to near-normal levels.
"What we've proven is that giving people NAC replenishes the glutathione stores," said Lee Herzenberg.
At the completion of the eight-week trial, most patients chose to take NAC for the following six months while the researchers continued monitoring the safety of the supplement. They found that patients suffered no ill effects that could be attributed to daily NAC ingestion.
Glutathione is not an anti-retroviral drug, stressed genetics professor Leonard (Len) Herzenberg, PhD. It does not decrease the amount of virus in patients' blood or increase their number of virus-fighting T cells, but it does restore the immune system, the researchers said.
Previous findings by the Herzenbergs and others show that T cells perform better in HIV-infected patients when their glutathione levels are replenished. Reversal of glutathione deficiency is also associated with improvement in many other diseases including diabetes, influenza and cystic fibrosis.
"The level of glutathione is tightly regulated in cells. If nature has gone to the trouble of maintaining those levels, logic says it should be restored to that level if you can," said Lee Herzenberg. "It's like a vitamin deficiency. Any vitamin deficiency would immediately be corrected, and we believe that this is equivalent to a vitamin deficiency."
The Herzenberg team hopes that the benefits of maintaining normal glutathione levels will encourage people suffering from long-term diseases to avoid lifestyle factors that deplete glutathione, such as exposure to ultraviolet light and alcohol consumption. They also recommend limited use of acetaminophen the active ingredient in common painkillers such as Tylenol because the risk of liver damage is increased for those with low glutathione levels.
The Herzenbergs are confident that the new findings will speed the introduction into the U.S. market of medicinal-quality NAC that AIDS patients and others can take to maintain normal glutathione levels. According to the researchers, medicinal-quality NAC can be purchased in Europe but currently can be found in the United States only as an unregulated food supplement.
Delaware-based BioAdvantex Pharma Inc. plans to begin distributing medicinal-quality NAC to the U.S. market in October under the brand name PharmaNAC.
"We have been pushing hard for this and we are pleased that Bioadvantex plans to broadly release the European-produced NAC, which is made under good manufacturing practices," said Lee Herzenberg.
Stanford co-authors of the new study are research associate Stephen De Rosa, MD; postdoctoral fellow Amoni Green, MD; research assistant Iwan Tjioe; senior software engineer Wayne Moore; consultant Stephen Ela, PhD; study coordinator J. Gregson Dubs, PhD (deceased); and research associate and director of the Stanford Shared FACS Facility, David Parks, PhD. Researchers at the University of California; the Comprehensive Cancer Center, Birmingham, Ala.; the Medical Institute of India; the University of Tokyo; and Kyoto University also contributed to the study.
Funding was provided by the National Cancer Institute, the National Institutes of Health, the Elan Pharmaceutical Corporation (Gainesville, Ga.), the University of California AIDS Research Program, Project Inform (San Francisco, Calif.) and the Unicorn Foundation (Chicago, Ill.).