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Department of Nutrition, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115
Dear Sir:
Our article drew no conclusions regarding chocolate consumption and risk of coronary heart disease (CHD). There was no discrepancy between the results from quintile analyses of individual saturated fatty acids and those from analyses treating each fatty acid as a continuous variable (1). In the quintile analyses, the relative risks (RRs) of CHD and results of tests for trends were not significant after multivariate adjustment, although there was a suggestion of increased risk with higher intake of each long-chain saturated fatty acid. In the analyses using continuous variables, somewhat stronger and significant associations were observed for stearic acid and the sum of all long-chain saturated fatty acids. This was likely due to greater statistical power and better control for confounding in the latter analyses. Nevertheless, the increased risk of CHD associated with higher consumption of these fatty acids was modest in both analyses. In contrast, we found a strong and significant inverse association between the ratio of polyunsaturated to saturated fatty acids and risk of CHD, which is consistent with the results of numerous metabolic studies (2, 3) and our previous findings (4). These data support the strategy of replacing saturated fat with unsaturated fat in reducing CHD risk.
The relation between chocolate consumption and risk of CHD is highly controversial. On one hand, chocolate is potentially harmful because of its stearic acid content, as pointed out by Connor (5). On the other hand, chocolate contains potentially beneficial nutrients, such as antioxidant phenols. Few epidemiologic data are available on the direct relation between chocolate consumption and risk of CHD. In the Harvard Alumni Study, Lee and Paffenbarger (6) found a lower risk of overall mortality in candy consumers than in nonconsumers (RR: 0.73; 95% CI: 0.60, 0.89). However, there was no dose-response relation between the amount of consumption and mortality; compared with nonconsumers, the RR was 0.64 for a consumption frequency of 1–3 times/mo, 0.73 for 1–2 times/wk, and 0.84 for 3 times/wk. In addition, the study did not differentiate between consumption of sugar candy and chocolate.
In the Nurses' Health Study, we assessed chocolate consumption [chocolate bars or pieces, 1-oz (28 g) serving size] in 1980, 1984, 1988, and 1990. After adjustment for coronary risk factors and intakes of meats and dairy products, we found no significant association between moderate chocolate intake and the incidence of CHD between 1980 and 1994. The RRs across categories of consumption (almost never, <1 time/mo, 1 time/wk, and 3–4 times/wk) were 1.0, 1.15 (95% CI: 0.96, 1.37), 1.08 (0.88, 1.32), and 1.11 (0.92, 1.34); P for trend: 0.28. These data suggest that moderate chocolate consumption is unlikely to have major adverse or beneficial effects on CHD risk. However, the effects of higher levels of consumption require further investigation.
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