More Evidence for Green Tea Use

by CP Staff

A recently published study investigated the possible mechanism in which green tea exerts numerous health benefits. The researchers in this study evaluated the effect of green tea on DNA damage. DNA, the genetic material in a cell, may be damaged by free radicals, which may result in cellular dysfunction. In this new study, researchers evaluated the effect of green tea on DNA damage both in vitro and in vivo.

In the first part of the study, investigators treated cultured human lymphocytes (white blood cells) with green tea, washed the cells and then treated the cells with hydrogen peroxide to induce oxidation. In the second part of the study, 18 healthy subjects were supplemented with one of two types of green tea or water as the control group for 4 weeks’ duration. The subjects received each of the 3 treatments (2 different teas or water) with 6 weeks in between changing the treatments administered to the groups.

Blood and urine samples were collected from each subject before and after receiving each intervention. The blood samples were used to test the resistance of lymphocyte DNA to the hydrogen-peroxide-induced challenge. The urine samples were used to evaluate 7,8-dihydro-2-deoxyguanosine, a marker of whole-body oxidative stress.

The results showed that in vitro, the cells treated with green tea were more resistant to oxidation-induced DNA damage. Similarly, the lymphocytes from the blood samples also showed increased resistance to oxidative damage from hydrogen peroxide. In fact, DNA damage was decreased in these cells by greater than 20 percent.

The researchers concluded, “The results indicate that green tea has significant genoprotective effects and provide evidence for green tea as a ‘functional food.’”

Reference:

Han KC, Wong WC, Benzie IF. Genoprotective effects of green tea (Camellia sinensis) in human subjects: results of a controlled supplementation trial. Br J Nutr. 2010 Sep 1:1-8. Published Online Ahead of Print.