Green tea polyphenol may protect against type 1 diabetes

Dr Stephen Hu and colleagues from research institutions in the US, China, and Japan, have discovered that epigallocatechin gallate (EGCG), a powerful antioxidant present in green tea, appears to prevent or delay the onset of type 1 diabetes in mice.

The researchers made the discovery whilst actually studying the effects of ECGC on another autoimmune disease – Sjogren's syndrome. The results showed that mice given a purified form of EGCG in their drinking water were 6.1-times more likely to be free of type 1 diabetes at 16-weeks-old and 4.2-times more likely to be free of the disease at 22-weeks-old. EGCG was also found to reduce the severity and delay the onset of Sjogren's syndrome.

"Our study is significant because we used a mouse model with the genetic defects that cause symptoms similar to human type 1 diabetes and Sjogren's syndrome, so the immune cells attack the pancreas and salivary glands until they are no longer functional," says Dr Hsu in a news release issued by the Medical College of Georgia. “Previous studies used another animal model that developed type 1 diabetes only after an injected chemical killed the insulin-producing cells. That may not accurately resemble disease development in humans, because type 1 diabetes is a genetic disease."

Gillespie K, Kodani I, Dickinson DP, et al. Effects of oral consumption of the green tea polyphenol EGCG in a murine model for human Sjogren's syndrome, an autoimmune disease. Life Sciences. 2008;83:581-588.

News release: Green tea may delay onset of type 1 diabetes. Medical College of Georgia. October 23rd 2008.