Amino Acid Supplement May Help People With
By Jill Lee
September 21, 1998
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
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, firstname.lastname@example.org.