Groene thee tegen oogziektes*
Uit een studie weliswaar met ratten blijkt dat catechinen, de bioactieve stoffen in
groene thee gemakkelijk zowel lens, retina en andere oogweefsels kunnen binnendringen en daar wel 20 uur actief zijn tegen mogelijke oxidatieschade die bijv. glaucoom en andere oogziektes veroorzaken.
New Evidence That Green Tea May Help Fight Glaucoma And Other Eye Diseases
Scientists have confirmed that the healthful substances found in green tea - renowned for their powerful antioxidant and disease-fighting properties - do penetrate into tissues of the eye. Their new report, the first documenting how the lens, retina, and other eye tissues absorb these substances, raises the possibility that green tea may protect against glaucoma and other common eye diseases. It appears in ACS's bi-weekly Journal of Agricultural and Food Chemistry.
Chi Pui Pang and colleagues point out 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. 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.
Pang and his colleagues 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.
Article: "Green Tea Catechins and Their Oxidative Protection in the Rat
Eye"
CONTACT:
Chi Pui Pang, Ph.D.
Department of Ophthalmology and Visual Sciences
The Chinese University of Hong Kong
Hong Kong Eye Hospital
Kowloon, Hong Kong
Source:
Michael Bernstein
American Chemical Society
(April 2010)
