Lipid metabolism, intestinal fermentation and mineral absorption in rats consuming black tea

Black tea polyphenols are associated with beneficial health effects such as prevention of cardiovascular diseases and cancer, mainly due to their antioxidative and hypocholesterolemic activity. In the present report, lipid peroxidation and metabolism in rats consuming liquid black tea were studied. Furthermore, faecal excretion of cholesterol and bile acids, formation of volatile fatty acids and mineral absorption were measured. Rats consuming black tea showed significantly decreased TBARS concentrations in urine as well as lowered esterified and total cholesterol contents in plasma as compared with a control group. However, TBARS contents in liver and plasma and cholesterol levels in liver were not affected by tea consumption. The lowered plasma cholesterol concentration in the tea group could not be explained by increased faecal excretion of cholesterol or bile acids. On the other hand, a relationship between decreased plasma cholesterol and significantly higher acetate concentrations in caecum, colon and portal blood of rats consuming black tea was assumed. Furthermore, Cu absorption was significantly increased by black tea consumption, while Fe absorption was not affected.