Nutr Metab (Lond)

Chocolate and Prevention of Cardiovascular Disease: A Systematic Review.

Ding EL, Hutfless SM, Ding X, Girotra S.

ABSTRACT: BACKGROUND: Consumption of chocolate has been often hypothesized to
reduce the risk of cardiovascular disease (CVD) due to chocolate’s high levels
of stearic acid and antioxidant flavonoids. However, debate still lingers
regarding the true long term beneficial cardiovascular effects of chocolate
overall. METHOD: We reviewed English-language MEDLINE publications from 1966
through January 2005 for experimental, observational, and clinical studies of
relations between cocoa, cacao, chocolate, stearic acid, flavonoids (including
flavonols, flavanols, catechins, epicatechins, and procynadins) and the risk of
cardiovascular disease (coronary heart disease (CHD), stroke). A total of 136
publications were selected based on relevance, and quality of design and
methods. An updated meta-analysis of flavonoid intake and CHD mortality was
also conducted. RESULTS: The body of short-term randomized feeding trials
suggests cocoa and chocolate may exert beneficial effects on cardiovascular
risk via effects on lowering blood pressure, anti-inflammation, anti-platelet
function, higher HDL, decreased LDL oxidation. Additionally, a large body of
trials of stearic acid suggests it is indeed cholesterol-neutral. However,
epidemiologic studies of serum and dietary stearic acid are inconclusive due to
many methodologic limitations. Meanwhile, the large body of prospective studies
of flavonoids suggests the flavonoid content of chocolate may reduce risk of
cardiovascular mortality. Our updated meta-analysis indicates that intake of
flavonoids may lower risk of CHD mortality, RR=0.81 (95% CI: 0.71-0.92)
comparing highest and lowest tertiles. CONCLUSIONS: Multiple lines of evidence
from laboratory experiments and randomized trials suggest stearic acid may be
neutral, while flavonoids are likely protective against CHD mortality. The
highest priority now is to conduct larger randomized trials to definitively
investigate the impact of chocolate consumption on long-term cardiovascular
outcomes.