Dr. Weeks’ Comment: Chocolate and health – the science is delightful!
“…higher chocolate intake is associated with a lower risk of future cardiovascular events…”
Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women.
To examine the association between chocolate intake and the risk of future cardiovascular events.
We conducted a prospective study using data from the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort. Habitual chocolate intake was quantified using the baseline food frequency questionnaire (1993-1997) and cardiovascular end points were ascertained up to March 2008. A systematic review was performed to evaluate chocolate consumption and cardiovascular outcomes.
A total of 20,951 men and women were included in EPIC-Norfolk analysis (mean follow-up 11.3±2.8 years, median 11.9 years). The percentage of participants with coronary heart disease (CHD) in the highest and lowest quintile of chocolate consumption was 9.7% and 13.8%, and the respective rates for stroke were 3.1% and 5.4%. The multivariate-adjusted HR for CHD was 0.88 (95% CI 0.77 to 1.01) for those in the top quintile of chocolate consumption (16-99 g/day) versus non-consumers of chocolate intake. The corresponding HR for stroke and cardiovascular disease (cardiovascular disease defined by the sum of CHD and stroke) were 0.77 (95% CI 0.62 to 0.97) and 0.86 (95% CI 0.76 to 0.97). The propensity score matched estimates showed a similar trend. A total of nine studies with 157,809 participants were included in the meta-analysis. Higher compared to lower chocolate consumption was associated with significantly lower CHD risk (five studies; pooled RR 0.71, 95% CI 0.56 to 0.92), stroke (five studies; pooled RR 0.79, 95% CI 0.70 to 0.87), composite cardiovascular adverse outcome (two studies; pooled RR 0.75, 95% CI 0.54 to 1.05), and cardiovascular mortality (three studies; pooled RR 0.55, 95% CI 0.36 to 0.83).
Cumulative evidence suggests that higher chocolate intake is associated with a lower risk of future cardiovascular events, although residual confounding cannot be excluded. There does not appear to be any evidence to say that chocolate should be avoided in those who are concerned about cardiovascular risk.
“…chocolate consumption seem to be associated with a substantial reduction in the risk of cardiometabolic disorders…”
Chocolate consumption and cardiometabolic disorders: systematic review and meta-analysis.
To evaluate the association of chocolate consumption with the risk of developing cardiometabolic disorders.
Systematic review and meta-analysis of randomised controlled trials and observational studies.
Medline, Embase, Cochrane Library, PubMed, CINAHL, IPA, Web of Science, Scopus, Pascal, reference lists of relevant studies to October 2010, and email contact with authors.
Randomised trials and cohort, case-control, and cross sectional studies carried out in human adults, in which the association between chocolate consumption and the risk of outcomes related to cardiometabolic disorders were reported.
Data were extracted by two independent investigators, and a consensus was reached with the involvement of a third. The primary outcome was cardiometabolic disorders, including cardiovascular disease (coronary heart disease and stroke), diabetes, and metabolic syndrome. A meta-analysis assessed the risk of developing cardiometabolic disorders by comparing the highest and lowest level of chocolate consumption.
From 4576 references seven studies met the inclusion criteria (including 114,009 participants). None of the studies was a randomised trial, six were cohort studies, and one a cross sectional study. Large variation was observed between these seven studies for measurement of chocolate consumption, methods, and outcomes evaluated. Five of the seven studies reported a beneficial association between higher levels of chocolate consumption and the risk of cardiometabolic disorders. The highest levels of chocolateconsumption were associated with a 37% reduction in cardiovascular disease (relative risk 0.63 (95% confidence interval 0.44 to 0.90)) and a 29% reduction in stroke compared with the lowest levels.
Based on observational evidence, levels of chocolate consumption seem to be associated with a substantial reduction in the risk of cardiometabolic disorders. Further experimental studies are required to confirm a potentially beneficial effect of chocolateconsumption.
Chocolate consumption is inversely associated with calcified atherosclerotic plaque in the coronary arteries: the NHLBI Family Heart Study.
BACKGROUND & AIMS:
While a diet rich in anti-oxidant has been favorably associated with coronary disease and hypertension, limited data have evaluated the influence of such diet on subclinical disease. Thus, we sought to examine whether chocolate consumption is associated with calcified atherosclerotic plaque in the coronary arteries (CAC).
In a cross-sectional design, we studied 2217 participants of the NHLBI Family Heart Study. Chocolate consumption was assessed by a semi-quantitative food frequency questionnaire and CAC was measured by cardiac CT. We defined prevalent CAC using an Agatston score of at least 100 and fitted generalized estimating equations to calculate prevalence odds ratios of CAC.
There was an inverse association between frequency of chocolate consumption and prevalent CAC. Odds ratios (95% CI) for CAC were 1.0 (reference), 0.94 (0.66-1.35), 0.78 (0.53-1.13), and 0.68 (0.48-0.97) for chocolate consumption of 0, 1-3 times per month, once per week, and 2+ times per week, respectively (p for trend 0.022), adjusting for age, sex, energy intake, waist-hip ratio, education, smoking, alcohol consumption, ratio of total-to-HDL-cholesterol, non-chocolate candy, and diabetes mellitus. Controlling for additional confounders did not alter the findings. Exclusion of subjects with coronary heart disease or diabetes mellitus did not materially change the odds ratio estimates but did modestly decrease the overall significance (p = 0.07).
These data suggest that chocolate consumption might be inversely associated with prevalent CAC.
WHAT ABOUT STROKE RISK?
“…significant inverse association between chocolate consumption and risk of developing stroke…”
Chocolate consumption and risk of stroke among men and women: A large population-based, prospective cohort study.
BACKGROUND AND AIMS:
Chocolate consumption may have a beneficial effect on cardiovascular health, but evidence from prospective cohort studies is still limited. We aimed to examine the prospective associations between chocolate consumption and risk of stroke among men and women in a large population-based cohort.
A total of 38,182 men and 46,415 women aged 44-76 years, and free of cardiovascular disease, diabetes, and cancer at baseline in 1995 and 1998, were followed up until the end of 2009 and 2010, respectively. We obtained data on chocolate consumption for each participant using a self-administrated food frequency questionnaire that included 138 food and beverage items. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) of stroke in relation to chocolate consumption.
During a median follow-up of 12.9 years, we identified 3558 incident strokes cases (2146 cerebral infarctions and 1396 hemorrhagic strokes). After adjustment for age, body mass index, life styles, dietary intakes, and other risk factors, chocolateconsumption was associated with a significant lower risk of stroke in women (HR = 0.84; 95% CI, 0.71-0.99). However, the association in men was not significant (HR = 0.94; 95% CI, 0.80-1.10). In addition, the association did not vary by stroke subtypes in either men or women.
Findings from this large Japanese cohort supported a significant inverse association between chocolate consumption and risk of developing stroke in women. However, residual confounding could not be excluded as an alternative explanation for our findings.