How Do the Phytonutrients in Green Tea Benefit Health?

This is part of our ongoing The Best Kept Secrets to Healthy Aging spotlight. Each day, we will be posting some of the great information that’s packed into our book, The Best Kept Secrets to Healthy Aging.

Today’s topic:
How Do the Phytonutrients in Tea Benefit Health?

In general, the catechins act throughout the body as very efficient antioxidants. The ability of these beneficial phytonutrients to detoxify free radicals and other harmful chemicals has been demonstrated beyond any doubt. In fact, the results of a study published recently in the Journal of Agricultural and Food Chemistry proved that the greater the catechin content of a dietary supplement, the greater its antioxidant capacity (measured in units of its “oxygen radical absorbance capacity” or “ORAC value”, which is a standard measure of in vitro antioxidant capacity).2

Other research has shown that the catechins and the theaflavins all possess about the same capacity to act as antioxidants.3 However, the total catechin content of green tea is about 2 to 3 times the total catechin plus theaflavin content of black tea (because some of the catechins are destroyed during the fermentation process). Therefore, when consumed in equal amounts, green tea should be 2 to 3 times more effective than black tea as an antioxidant (though black tea has unique benefits all its own). This has been confirmed in experiments on hamsters that were fed diets containing very high levels of cholesterol – adding green tea to the diet of these hamsters was about twice as effective in preventing the oxidation of the cholesterol in their blood as was adding black tea.4 Furthermore, men and women who smoke cigarettes typically exhibit a vastly accelerated rate of oxidative damage to the DNA in their bodies; when they drink 4 cups of green tea daily, they experience a large decrease in DNA free radical damage.5,6

Next Best Kept Secrets to Healthy Aging topic:
Healthy Blood Pressure with Tea

References:
2. Seeram NP, Henning SM, Niu Y, Lee R, Scheuller HS, Heber D. Catechin and caffeine content of green tea dietary supplements and correlation with antioxidant capacity. J Agric Food Chem 2006;54:1599-1603.
3. Leung LK, Su Y, Chen R, Zhang Z, Huang Y, Chen ZY. Theaflavins in black tea and catechins in green tea are equally effective antioxidants. J Nutr 2001;131:2248-2251.
4. Vinson JA, Dabbagh YA. Effect of green and black tea supplementation on lipids, lipid oxidation and fibrinogen in the hamster: Mechanisms for the epidemiological benefits of tea drinking. FEBS Lett 1998;433:44-46.
5. Hakim IA, Harris RB, Brown S, Chow HH, Wiseman S, Agarwal S, Talbot W. Effect of increased tea consumption on oxidative DNA damage among smokers: A randomized controlled study. J Nutr 2003;133:3303S-3309S.
6. Hakim IA, Harris RB, Chow HH, Dean M, Brown S, Ali IU. Effect of a 4-month tea intervention on oxidative DNA damage among heavy smokers: Role of glutathione S-transferase genotypes. Cancer Epidemiol Biomarkers Prev 2004;13:242-249.


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