Green Tea May Fight Eye Diseases

(February 19, 2010) - Go ahead and drink up, green tea that is. Scientists say they have confirmed that the healthful substances found in green tea - renowned for their powerful antioxidant and disease-fighting properties - penetrate into tissues of the eye. Their new report, the first documenting how the lens, retina and other eye tissues (Read about "The Eye") absorb these substances, raises the possibility that green tea may protect against glaucoma (Read about "Glaucoma") and other common eye diseases. The study appears in the Journal of Agricultural and Food Chemistry.

Researchers say that so-called green tea "catechins" have been among a number of antioxidants thought capable of protecting the eye. Those include vitamin C, vitamin E, lutein and zeaxanthin. (Read about "Vitamins & Minerals") Until now, however, nobody knew if the catechins in green tea actually passed from the stomach and gastrointestinal tract into the tissues of the eye.

The research resolved that uncertainty in experiments with laboratory rats that drank green tea. Analysis of eye tissues showed beyond a doubt that eye structures absorbed significant amounts of individual catechins. The retina, for example, absorbed the highest levels of gallocatechin, while the aqueous humor tended to absorb epigallocatechin. The effects of green tea catechins in reducing harmful oxidative stress in the eye lasted for up to 20 hours. "Our results indicate that green tea consumption could benefit the eye against oxidative stress," the report concludes.