Habitual chocolate consumption and risk of cardiovascular disease among healthy men and women
- Chun Shing Kwok1,2,
- S Matthijs Boekholdt3,
- Marleen A H Lentjes4,
- Yoon K Loke5,
- Robert N Luben4,
- Jessica K Yeong6,
- Nicholas J Wareham7,
- Phyo K Myint1,
- Kay-Tee Khaw4
- 1Epidemiology Group, Division of Applied Health Sciences, School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK
- 2Cardiovascular Institute, University of Manchester, Manchester, UK
- 3Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands
- 4Department of Public Health & Primary Care, University of Cambridge, Cambridge, UK
- 5Department of Public Health & Primary Care, Norwich Medical School, University of East Anglia, Norwich, UK
- 6Lancashire Teaching Hospital NHS Foundation Trust, Preston, UK
- 7Medical Research Council Epidemiology Unit, Cambridge, UK
- Correspondence to Dr Chun Shing Kwok, School of Medicine & Dentistry, University of Aberdeen, c/o Professor Phyo Kyaw Myint, Room 4:013, Polwarth Building, Foresterhill, Aberdeen AB25 2ZD, UK;
- Received 22 October 2014
- Revised 25 March 2015
- Accepted 20 April 2015
- Published Online First 15 June 2015
Objective To examine the association between chocolate intake and the risk of future cardiovascular events.
Methods 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.
Results 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).
Conclusions 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.