7 August 2009
Anthocyanins linked to improved cholesterol levels
Increased intakes of antioxidant anthocyanins may improve levels of HDL and LDL cholesterol, according to results of a new human study with 120 people.
Consumption of berry-derived anthocyanin supplements resulted in a 13.7 per cent increase in levels of HDL cholesterol, and a 13.6 per cent reduction in levels LDL cholesterol, according to findings published online ahead of print in the American Journal of Clinical Nutrition.
Chinese scientists from Sun Yat-Sen University randomly assigned 120 people aged between 40 and 65 with abnormal blood lipid levels (dyslipidemia) to receive either a daily dose of 320 mg of anthocyanins or placebo for 12 weeks.
The study builds on earlier results form animal studies, which showed beneficial effects of the antioxidant compounds on lipid levels.
High cholesterol levels, hypercholesterolaemia, have a long association with many diseases, particularly cardiovascular disease (CVD), the cause of almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated €169bn ($202bn) per year.
Using a double-blind, randomised, placebo-controlled trial design, the Chinese researchers studied the effects of a twice daily dose of 160 mg anthocyanins on the lipid levels of the participants.
After 12 weeks of supplementation, HDL cholesterol levels increased by almost 14 per cent in the anthocyanin group, compared to a rise of only 2.8 per cent in the placebo group. Furthermore, LDL cholesterol levels decreased by 13.6 per cent in the anthocyanin group, compared to an increase of 0.6 per cent in the placebo group.
The removal of cholesterol from cells, the so-called cellular cholesterol efflux, was found to increase by 20 per cent in the anthocyanin group, compared to a 0.2 per cent in the placebo group.
In terms of the potential mechanism, the activity of a protein called plasma cholesteryl ester transfer protein (CETP) was studied. CETP works by collecting triglycerides from LDL and exchanging them for cholesteryl esters from HDL, and also the reverse.
Supplements of the anthocyanins was found to reduce the activity of CETP by 6.3 per cent, while CETP activity fell by only 1.1 per cent in the placebo group, said the researchers.
“The change in HDL cholesterol was negatively correlated with the change in CETP activity,” they wrote. “The change in LDL cholesterol was positively correlated with the change in CETP mass,” they added.
“Anthocyanin supplementation in humans improves LDL- and HDL-cholesterol concentrations and enhances the cellular cholesterol efflux to serum,” wrote the researchers. “These benefits may be due to the inhibition of CETP,” they concluded.