Cross-cultural associations:

Nutrients, smoking and 25-year coronary heart disease rates in the 16 cohorts

A high saturated fat intake, a low flavonoid intake and smoking are associated with high CHD mortality rates

Three factors combined – saturated fat, flavonoids, and smoking – account for 90% of the differences in 25-year CHD mortality rates among the 16 cohorts in the Seven Countries Study. In univariable models average saturated fat intake at baseline was strongly associated with CHD mortality, while average flavonoid intake was inversely related. The prevalence of smoking at baseline was not related to CHD mortality rates. However, multivariable modeling showed that saturated fat and smoking were positively and that flavonoid intake was inversely related to CHD mortality rates.

Interpretation of the results

Based on mechanistic studies confirming these associations we conclude that saturated fat increases the cholesterol-rich LDL-lipoprotein fraction and the risk of atherosclerosis. Smoking promotes LDL oxidation that might be offset by the strong antioxidant effects of flavonoids. Trials showed that replacing saturated with polyunsaturated fat reduces CHD risk. Prospective cohort studies found that stopping smoking and a high intake of flavonoids are associated with a lowered CHD risk. These results found at the population level in the Seven Countries Study are thus in agreement with those obtained in experimental and prospective cohort studies, strengthening the interpretation of cause and prevention.