Erythrocyte fatty acids, plasma lipids, and cardiovascular disease in rural China. Cardiovascular disease (CVD) mortality (coronary heart disease, hypertensive heart disease, and stroke), plasma lipids, and red blood cell fatty acid composition were examined in an ecologic study in 65 rural counties in the People's Republic of China. Means of plasma total cholesterol, triglyceride, low-density-lipoprotein (LDL) cholesterol, and high-density-lipoprotein (HDL) cholesterol concentrations were substantially lower and the ratio of HDL cholesterol to total cholesterol was higher in this Chinese population than in Western populations. Mortality rates for CVD in China were well below Western values. Within China neither plasma total cholesterol nor LDL cholesterol was associated with CVD. A strong inverse correlation between red blood cell oleate concentrations and CVD was observed. However, red blood cell oleate concentrations were not associated with plasma cholesterol but were strongly negatively associated with arachidonate concentrations, suggesting potential diminution of CVD by oleate through reduced platelet aggregability. The results indicate that geographical differences in CVD mortality within China are caused primarily by factors other than dietary or plasma cholesterol. 