Dark chocolate improves lipid profiles
MedWire News: Dark chocolate and cocoa have beneficial effects on total and low-density lipoprotein (LDL) cholesterol concentrations, suggests a meta-analysis of published studies.
These effects were stronger in individuals with higher risk for cardiovascular disease (CVD) and in studies with a relatively shorter duration, note the researchers.
They speculate that the observed reductions in these lipid parameters "may be attributable to flavonoids contained in cocoa and dark chocolate."
Oluwabunmi Tokede (Brigham and Women's Hospital, Boston, Massachusetts, USA) and colleagues searched the literature for randomized controlled trials assessing the effects of flavanol-rich cocoa products or dark chocolate on lipid profiles.
A total of 10 clinical trials, with 320 participants, were included in the analysis. Treatment duration ranged from 2 to 12 weeks.
The researchers report that the post-intervention reductions in mean concentrations of total and LDL cholesterol, when comparing active treatment with placebo, were a significant 6.23 mg/dl (0.16 mmol/l) and 5.90 mg/dl (0.15 mmol/l), respectively.
Corresponding reductions for high-density lipoprotein (HDL) cholesterol and triglycerides were 0.76 mg/dl (0.02 mmol/l) and 5.06 mg/dl (0.06 mmol/l), but these did not reach statistical significance.
Further subgroup analyses, which considered variables such as study duration, dosage, and health status, revealed significant differences in the mean LDL cholesterol concentrations for several variables in the dark chocolate/cocoa groups, note the authors.
Specifically, for short study duration (2 weeks) there was a significant reduction in LDL cholesterol of 8.44 mg/dl (0.22 mmol/l) compared with a nonsignificant reduction of 1.67 mg/dl (0.04 mmol/l) for medium duration (4-12 weeks).
Reductions were also greater for individuals at high CVD risk compared with those who were healthy (7.23 vs 5.77 mg/dl [0.19 vs 0.15 mmol/l], respectively) and those from Europe compared with the USA (7.13 vs 6.95 mg/dl [0.18 vs 0.18 mmol/l]).
The researchers conclude, in the European Journal of Clinical Nutrition, that "additional studies to evaluate the optimal dose of cocoa consumption and long-term effects of dark chocolate on serum lipids are needed to help appraise the net benefit of dark chocolate consumption on health."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Nikki Withers