Interaction of smoking and dietary habits modifying the risk of coronary heart disease in women: results from a case-control study

BACKGROUND/OBJECTIVES: Smoking is a strong risk factor for coronary heart disease particularly in women. The risk may be aggravated by dietary habits, though.

SUBJECTS/METHODS: The Coronary Risk for Atherosclerosis Study (CORA) compares dietary, lifestyle, biochemical, and clinical factors in 200 consecutive pre- and postmenopausal women with incident coronary heart disease to those of 255 age-matched population-based controls. A mixed logistic regression model was used to assess the possible interactions between smoking habits and dietary patterns.

RESULTS: Each increase of 100 kcal energy intake per day was positively associated with coronary risk (OR 1.10, 95% CI 1.03-1.17; p = 0.006). Doubling the intake of alcohol and vegetables was negatively related with coronary risk (alcohol: OR 0.61, 95% CI 0.50-0.73; p < 0.001; vegetables: OR 0.50, 95% CI 0.032-0.080; p = 0.003). In contrast, doubling the intake of meat was associated with an increase of coronary risk, but only in smoking women (OR 2.61, 95%CI 1.58-4.29; p < 0.001). In smoking women a high meat-over-vegetable-ratio indicated an even higher risk (ratio of 2.0: OR 5.77, 95% CI 2.13-15.67; p < 0.001), while a low meat-over-vegetable-ratio did not have a significant impact on coronary risk (ratio of 0.5: OR 1.28, 95% CI 0,78-2.09).

CONCLUSIONS: This explorative analysis of the CORA-study indicates that a high intake of meat is significantly associated with an increase in coronary risk particularly in smoking women, and may account for part of the unadjusted risk of smoking.