The data of observational studies suggested that 1 cup/d of green tea rather than black tea is correlated to a 10% reduction in the risk of coronary artery diseases development. In addition, a large cohort study also found that green tea consumption, rather than black tea, is significantly associated with a decreased risk of mortality from CVD. Recently, Zhao et al. conducted a meta-analysis investigating the effect of black tea on blood cholesterol concentrations on the basis of 10 RCTs. However, the overall meta-analysis and subgroup analyses of the study were based on the combined populations with different health status, which might limit the drawing of conclusions about the specific populations. In general, this meta-analysis indicated that black tea consumption has no significant effect on blood cholesterol concentrations, while a previous meta-analysis suggested that green tea consumption can significantly lower the blood TC and LDL-C concentrations. Therefore, black tea and green tea consumption might possess inconsistent effect on cholesterol concentrations and CVD risk. The null effect of black tea on blood cholesterol may be partly because black tea contains less antioxidant compounds than green tea. Additionally, the amount and composition of catechins are substantially various between black tea and green tea due to the different degrees of fermentation. It has been reported that catechins constitute 80% to 90% of total green tea flavonoids, whereas they only constitute 20% to 30% of black tea flavonoids. This is mainly due to the fact that black tea catechins are usually converted to some complex varieties, such as thearubigins and theaflavins during the oxidation process in the manufacture of black tea. Animal studies have revealed that MK-1775 administration of catechins can significantly increase the activity of hepatic LDL-receptor and reduce plasma and liver cholesterol concentrations. In addition, Chan et al. suggested that catechins can inhibit cholesterol absorption by enhancing the cholesterol fecal excretion in hamsters. Consistent with the animal studies, a previous in vitro study has suggested that catechins can directly inhibit the biosynthesis of cholesterol by selectively inhibiting the activity of squalene epoxidase. Thus, if catechins account for the major beneficial effect of green tea on cholesterol concentrations, the comparatively lacking favorable effect of black tea on blood cholesterol concentrations is reasonable. In addition, all of the included studies selected participants with TC concentrations lower than 240 mg/dL, and most of the trials included subjects with high concentrations of HDL-C. This may also partially explain the null effects of black tea on TC and HDL-C concentrations, because TC and HDL-C concentrations may fluctuate in a certain range in the subjects with normal cholesterol conditions. Therefore, black tea consumption may not significantly affect the physiological regulation of blood cholesterol concentrations in these subjects.