Aquatic Food Consumption, Blood Docosahexaenoic Acid and Chronic Diseases in Chinese Rural Populations

Abstract

An epidemiological survey of 65 rural counties (6500 subjects) in China showed that fish consumption correlated significantly with the levels of omega-3 docosahexaenoic acid (DHA) in red blood cells (RBC) (r=0.640, P<0.001), selenium (r=0.467, P<0.001) and glutathione peroxidase (r=0.333, P<0.01) in plasma. A strong inverse correlation between DHA in RBC and cardiovascular disease (CVD) was found. The strongest correlation was the combination of DHA and oleic acid. RBC DHA itself also correlated negatively and significantly with most chronic diseases and appeared to be more protective than other omega-3 fatty acids. In a follow-up study, three regions (coastal, fresh-water and inland) were selected to examine the effects of contrasting diets in pregnancy and lactation. The plasma choline phosphoglyceride (CPG) DHA was not significantly different in the coastal and fresh-water areas but both were greater than found inland. A similar difference was found in the colostrum. These results demonstrate (i) Consumption of fresh-water fish has nearly the same effects on blood and colostrum omega-3 status as consumption of marine foods (ii) The lower DHA level of inland pregnant women is consistent with the higher incidence of CVD and other chronic diseases found in the 65 counties study in China.