September 30 — A new Italian study has shown, for the first time, that consuming moderate amounts of dark chocolate can significantly reduce levels of C-reactive protein (CRP) . Dr Romina di Giuseppe (Catholic University, Campobasso, Italy) and colleagues report their findings in the October 2008 issue of the Journal of Nutrition.
The results are the first to come out of a large epidemiological study, the Moli-sani Project, which is aiming to recruit 25,000 individuals living in the Molise region of Italy to investigate environmental and genetic factors responsible for cardiovascular disease and cancers.
"The reduction induced by moderate consumption of dark chocolate corresponds in clinical terms to a significant reduction in the risk of cardiovascular disease," senior author Dr Licia Iacoviello (Catholic University, Campobasso, Italy) told heartwire. "The lowering of CRP that we saw corresponds to a shift from medium risk of cardiovascular disease to low risk and is the first time an association between consumption of dark chocolate and inflammation has been found in a population study," she added.
But don't eat too much
Of 4849 subjects in good health and free of risk factors in the Moli-sani Project, the researchers identified 1317 who did not eat any chocolate and 824 people who ate dark chocolate regularly. They related the levels of CRP in their blood to their usual chocolate intake.
After adjustment for age, sex, social status, physical activity, systolic blood pressure (BP), body-mass index (BMI), waist/hip ratio, food groups, and total energy intake, dark-chocolate consumption was inversely associated with CRP (p=0.038). Mean serum CRP concentrations were 1.32 mg/L in nonconsumers of dark chocolate and 1.10 mg/L in those who ate dark chocolate (p<0.0001).
The 17% average reduction observed may appear small, but it is enough to decrease the risk of cardiovascular disease for one-third in women and one-fourth in men, the researchers say.
But they stress that a J-shaped curve was observed between dark-chocolate consumption and CRP concentrations: those who ate up to 1 serving (20 g) every 3 days had CRP concentrations significantly lower than those who ate none or those who ate larger amounts.
This moderate amount corresponds to a small square of chocolate two or three times a week, the researchers note, stressing that, beyond these amounts, the beneficial effect tends to disappear. "If you increase the consumption, the protection is lost, similar to the effects of wine," Iacoviello said.
"It could be that if you increase the amount of chocolate by too much, the increase in lipids and calories overcomes the effects of the antioxidants," she speculates.
The present study adds to previous work that has shown that moderate amounts of dark chocolate appear to have a beneficial effect on blood pressure, the researchers note, and "adds new insight into the relationship between flavonoid-rich foods, inflammation, and cardiovascular protection."
Nevertheless, "additional studies are necessary to explain the mechanisms linking dark-chocolate consumption and regulation of serum CRP concentrations," they conclude.
The authors have disclosed no relevant financial relationships. The Moli-sani Project is supported by research grants from Pfizer Foundation (Rome).
1. Di Giuseppe R, di Castelnuovo A, Centritto F et al. Regular consumption of dark chocolate is associated with low serum concentrations of C-reactive protein in a healthy Italian population. J Nutr 2008; 138: 1939-1945