The preliminary study is published in the Journal of Allergy and Clinical Immunology and was a joint project between the University of Sheffield, UK, and Baylor College of Medicine, in Texas, USA.
The research team did test tube experiments on a green tea flavonoid called epigallocatechin gallate (EGCG) and showed that it binds with CD4 immune system T-cell receptors and stops HIV from doing the same.
One of the researchers, Professor Mike Williamson of the Department of Molecular Biology and Biotechnology at the University of Sheffield said, “”Our research shows that drinking green tea could reduce the risk of becoming infected by HIV, and could also slow down the spread of HIV.”
Before people jump to conclusions that this study suggests green tea could deny HIV a foothold in the immune system, critics are cautious and say it is very early days.
Compounds that show good results at the “micro” level of cells in a test tube do not necessarily have the same effect at the “macro” level of immune systems in living organisms.
Prof Williamson was keen to point out that green tea is not a cure, and neither is it a safe way to avoid infection. The study merely suggests that EGCG ” has potential use as adjunctive therapy in HIV-1 infection”.
In other words, Prof Williamson said, “it should be used in combination with conventional medicines to improve quality of life for those infected”.
He also mentioned that further studies to find out how much effect different amounts of green tea might have are already under way.
The study was sponsored by the US National Institutes of Health, and a range of research, education and other funds.
Last September, a study from Japan was published in the Journal of the American Medical Association (JAMA) that reported high consumption of green tea was linked to reduced overall risk of death due to all causes and cardiovascular disease.
Other studies have also found positive links between green tea consumption and cancer.
“Epigallocatechin gallate, the main polyphenol in green tea, binds to the T-cell receptor, CD4: Potential for HIV-1 therapy.”
Williamson MP, McCormick TG, Nance CL, Shearer WT.
The Journal of Allergy and Clinical Immunology, December 2006 (Vol. 118, Issue 6, Pages 1369-1374).
Written by: Catharine Paddock
Writer: Medical News Today