Abstract

Over 300 female farmers from 18 regions in various parts of Japan were examined for high density lipoprotein cholesterol (HDL) in the serum. Based on the HDL levels, three examinees with the highest HDL and another three with the lowest HDL were selected from each region to form the high HDL group (high group, 54 subjects) and the low HDL group (low group, 54 subjects), respectively, so that any geographical effects on HDL could be excluded. The 108 subjects were examined for serum lipid biochemistry, anthropometry, and nutrient intake (by collection and analyses of 24-hour duplicates of the diet). While the HDL level in the high group (64.8 +/- 11.2 mg/100 ml, mean +/- SD) was significantly (p less than 0.01) higher than in the low group (31.4 +/- 5.6 mg/100 ml), the low group had a higher serum triglyceride level and was more obese than the high group. Nutritional analyses of the diets taken by each group member revealed that the diets of both groups were typically Japanese (ie, low calorie intake at ca 2000 kcal/day, higher dependency on carbohydrate, equal amounts of protein from animals and vegetables, and large fish intake) and essentially similar (p less than 0.05) in nutritional constituents, such as total energy, carbohydrate, fibre, saturated/unsaturated fatty acid ratio or sodium chloride, except that members of the high group took significantly (p less than 0.01 approximately 0.05) more protein and fat (thus more of both saturated and unsaturated fatty acids). None of the nutritional items studied appeared to explain the different HDL levels in the two groups.