Can Green Tea Prevent Heart Disease?

The animal study, published in the American Heart Association Journal, Circulation (2004, vol 80, issue 3), investigated the effect of epigallocatechin gallate (EGCG), the major antioxidant in green tea, on both new and established plaque in mice fed a high cholesterol diet and bred to rapidly develop atherosclerotic plaque. Researchers at the Atherosclerosis Research Center, Cedars-Sinai Medical Center, administered EGCG or a control substance five days a week to mice following right carotid artery injury at 28 weeks of age. Arterial injury induced the formation of new plaque in the mice. Researchers examined the arteries of the mice after 21 and 42 days.

Researchers found that the EGCG-treated mice had significantly reduced new plaque formation at the injury site, compared to the control mice. Findings revealed that EGCG reduced atherosclerotic plaque size at 21 and 42 days by 55% and 73%, compared with the control treatment. However, EGCG had no beneficial effect on established plaque. "This differential effect highlights the importance of time of initiation of antioxidant therapy for atherosclerosis suppression," the study authors conclude. These results suggest that green tea antioxidant treatment is effective in the early but not later stages of plaque formation.