Cholesterol is always indicted as the "bad guyn for causing a wide range of diseases in adults. But it is a chemical present in all animals and crucial in human bodies for such important processes as the manufacture of cell membranes and the adhesion of cells. There are two types of cholesterol: one is the so-called bad cholesterol (LDL and VLDL- cholesterol) that accumulates in tissues and the other is the "good, cholesterol (HDL-cholesterol) that collects excessive cholesterol from the tissues. If the amount of bad cholesterol in the blood increases too much, it is deposited on the walls of blood vessels and can lead to atherosclerosis. Atherosclerosis in conjunction with high blood pressure can cause myocardial infarction and cerebral infarction. Good cholesterol, however, prevents atherosclerosis and must exist in a proper balance with bad cholesterol for proper health.
Prof. Muramatsu,(#7) has demonstrated in experiments with rats that green tea catechin restricts the excessive buildup of blood cholesterol. When rats were fed a diet high in fat, the amount of bad cholesterol in the blood increased rapidly. But the addition of only 1% catechin to the food checked the increase of bad cholesterol (LDL) with only minimal effect on the amount of good cholesterol (HDL). In another series of experiments, rats fed normal food with catechin exhibited no decrease in blood cholesterol and remained unaffected by the supplement. We can see from these results that green tea catechin acts to limit the excessive rise in blood cholesterol. Recently Dr. Goto(#8) reported similar results for human blood cholesterol.

(#7) K. Muramatsu and Y. Hara, J. Nutr. Sci. Vitaminol, 32, 613 (1986). (#8) K. Goto, S. Kanaya and Y. Hara, Proc. of the International Symp. on Tea Science, 314 (Shizuoka, Japan;August,1991)