Amino Acid Supplement May Help People With HIV

Scientists at the Children's Nutrition Research Center in Houston, Texas, may help settle a controversy: can people with HIV improve their antioxidant status with supplements of the amino acid cysteine?

They might, according to a soon-to-be published study from the Houston center, a cooperative research facility of the Agricultural Research Service and Baylor College of Medicine. Nutrition scientists at ARS, the chief scientific agency of the U.S. Department of Agriculture, have long studied food antioxidants and their role in human health.

Medical researchers know that people with HIV can develop lower levels of the antioxidant glutathione (GSH). HIV patients with low glutathione levels get more secondary infections and cancers and have a higher mortality rate.

Some scientists have shown that a form of cysteine called NAC (N-acetylcysteine) boosts GSH levels. Other studies have suggested NAC is ineffective. A large industry is built around selling GSH and NAC supplements.

In the Houston study, HIV-infected volunteers who took NAC increased their glutathione- making efficiency and the amount of glutathione in blood cells. This confirms other findings in the U.S. and in Brazil, Mexico and Germany that NAC is helpful.

The study also provides an explanation of why people with HIV have low glutathione. It suggests that the HIV-infected volunteers sometimes were producing the antioxidant too slowly--rather than using it too quickly. The scientists arrived at this conclusion after comparing GHA synthesis rates in five HIV-infected research volunteers and five healthy participants.

Although the study was small, the researchers used one of the most in-depth methods available to study how the body synthesizes GHA. They used amino acids tagged with stable isotopes--easily traced, non-radioactive forms of elements--to measure the speed of glutathione synthesis.

The research has been accepted for publication in the American Journal of Physiology.

Scientific contact: Farook Jahoor, USDA-ARS Children's Nutrition Research Center at Baylor College of Medicine, Houston, Texas, phone (713) 798-7084, fax (713) 798-7119, fjahoor@bcm.tmc.edu.