Tea Against Cholesterol
Studies in several countries have found all three kinds of tea to have some effect in reducing cholesterol in blood fats, though oolong seems to get the best results. Triglycerides and cholesterol are the two important fat substances in the bloodstream. These are essential for many things, but cholesterol also builds up on the walls of the arteries, causing them to narrow and restrict blood flow, a condition known as atherosclerosis.
As far back as 1967 British researchers noted that black tea reduced cholesterol. Around 1980, tests in Japan indicated that regular drinking of oolong tea reduces cholesterol and neutral fats, and gives some help in cases of hypertension and coronary heart disease.
A University of California survey found less atherosclerosis among tea drinkers than coffee drinkers. This is borne out by findings at the Fujian Institute. Rabbits that drank oolong tea while on a high cholesterol diet had smaller, more scattered, and less severe sclerosis spots on the aorta wall than the control group, which drank water.
Japanese researchers, testing with green tea, concluded that it is the catechinc that act to cut cholesterol, and increase the excretion of total lipids and cholesterol in the feces. Fibrinogen is a globulin in the blood which turns into fibrin to help in normal clotting. But in patients with abnormally high fibrogen levels, fibrin joins with arterial wallcholesterol to form plaque. One catechin isolated from green tea helps dissolve fibrin. Six years of treatment with a medicine made from oxidized tea polyphenols on 214 cardiovascular patients with a high fibrinogen level brought it back to normal for 81 percent of them.
Chow, K. and Kramer, I. (1990). All the Tea in China. San Francisco: China Books.