Can Green Tea Fight AIDS?
Compound in drink prevents infection in lab tests
THURSDAY, Nov. 13, 2003 (HealthDayNews) -- Green tea is said to have near-miraculous curing powers, and new research now boosts the theory that the beverage may someday play a role as an AIDS fighter.
Experts caution that the results of a newly released laboratory study from Japan are preliminary and may not mean anything outside of test tubes. But the research does suggest heavy doses of green tea could prevent the AIDS virus from infecting the body's immune cells.
"It really hasn't been proven yet, but it's something that ought to be pursued," says Dr. William T. Shearer, a professor of pediatrics and immunology at Baylor College of Medicine and author of a commentary on the findings.
Green tea, a popular drink in Asia, has been called a potential treatment for stomach disorders, cancer and bacterial infections, among many other ailments from high cholesterol to tooth decay. Scientists suspect the ingredient behind its apparent powers is a compound known as epigallocatechin-3-gallate, or EGCG.
Researchers at the University of Tokyo examined the effects of EGCG on the process of HIV infection. They report their findings in the November issue of the Journal of Allergy and Clinical Immunology.
The researchers found the substance blocked the AIDS virus from latching onto the T-cells. When HIV successfully attacks these "spark plugs" of the immune system, the body loses its ability to fight off infection and becomes susceptible to numerous potentially deadly illnesses, Shearer says.
This is promising because existing AIDS drugs have limited powers, Shearer says. They target cells that have already been infected, but don't stop the infection of cells in the first place. "There are always new infections that are taking place every day, every hour, every minute," he says. "A drug that could prevent new infections would be a wonderful adjunct medication."
So, should AIDS patients rush out to the health-food store to stock up on green tea? Shearer and other experts don't think so. "Nobody's ready to say this proves that one ought to drink gallons of green tea every day," Shearer says.
For one, it may take quite a lot of green tea each day to have any impact. Research has suggested that two cups of green tea a day won't take patients anywhere near the blood level they may need, Shearer says.
For another thing, researchers haven't tried their theories on humans. Also, it's not clear whether too much green tea in the bloodstream could be toxic, says Frank Edward Myers III, an AIDS expert and epidemiologist at Scripps Mercy Hospital in San Diego.
Even so, researchers are hopeful about harnessing the powers of green tea into a drug. "It's very exciting," says Dr. Christopher Randolph, an associate clinical professor of allergy and immunology at Yale University, "but I'd be cautious about saying something may be applicable tomorrow."
Myers also urges caution. "Early results like these can often be encouraging but later found to be dead ends, not useful in developing treatments," he says. "A lot more testing needs done before this can be applied in patient care."