Monday, January 31, 2011

TEAS AND CORONARY RISK

There is an ongoing belief that tea drinking washes away the fats that we eat and so reduces fat accumulation in arteries and lowers the incidence of CAD. Is this true? Many Chinese believe that after a fatty meal, drinking tea is essential.
Well, it is not entirely wrong, I think.
The Jan 19 issue of the American Journal of Clinical Nutrition carried an article from China on this topic. Dr Ze-Mu Wang and colleagues from the First Affiliate Hospital of the Medical University of Nanjing did a meta-analysis of 18 clinical trails involving the drinking of black tea and risk of CAD, and another 5 studies of the drinking of green tea and the risk of heart disease. They found that the drinking of black tea was not associated with any reduction in risk of CAD. But the drinking of green tea seem to confer some protection against CAD.
The theory is that tea contains a substance called " catechins " which has the effect of inhibiting oxidation, and reducing inflammation, two words that are very important in the initiation of CAD. The amount of catechins in the tea depends on the fermentation process and green tea contains more catechins.
I suppose there is nothing wrong with drinking green tea, as there is no downside, besides cost, I suppose. Whether it helps or not, will need much more work. Remember that this is a meta-analysis, with all its deficiencies. The samples and cohorts, may not all be properly matched and the studies may have slightly different endpoints, although they all have to do with the use of green tea in the reduction of CAD. As always, it is best to take meta-analysis ( a cheaper way of doing research ), with a small pinch of salt.
Be that as it may, if you wish to drink tea, no harm choosing green tea. It may help. At worse, it does no harm, and it is quite nice to drink. I like it. As for white tea, there is almost no data.

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