Dietary intake and serum total cholesterol level: their relationship to different lifestyles in several Japanese populations

Serum total cholesterol level and dietary intake were surveyed 1975--1977 in six Japanese population groups with different lifestyles, including groups in both rural (Akita and Kochi) and urban (Osaka) areas. Clerical workers in Osaka, who had the most westernized lifestyle of all the study groups, had the highest mean serum total cholesterol level (202 mg/dl for men ages 40--49 and 50--59 years), while farmers in Akita had the lowest mean serum total cholesterol level (163 mg/dl for men 40--49 years old, 159 mg/dl for men 50--59 years old, 165 mg/dl for men 60--69 years old). Nutrient intake data for mean ages 40--59 years showed 23% of calories from fat for clerical workers in Osaka, the highest among the study groups, whereas farmers in Akita showed a low level of 14%. The ratio of dietary polyunsaturated to saturated fatty acids was over 1.1 for all groups. Cholesterol intake was 339--487 mg/day. Total carbohydrate as a percentage of calories was 53--65%; 75--80% of carbohydrate energy was ingested from cereals. Sugar accounted for less than 3.5% of total calories. In the cross-group correlation analysis between dietary lipid intake and serum total cholesterol, a significant strong positive correlation was found between the dietary lipid factor (phi) of Keys et al. and the mean serum total cholesterol level. A weak but significant correlation was observed between the dietary lipid factor and serum total cholesterol for individual inhabitants of Osaka.