[Dietary and serum fatty acid compositions among six Japanese populations]

Dietary and serum fatty acid composition and their relations were investigated in men aged 40-59 years from six geographical and occupational populations: fishermen, three farming populations, urban clerical and manual workers. 1. Mean dietary intake of saturated, monounsaturated and polyunsaturated fatty acids were higher in urban workers than in the other populations. Mean dietary intake of omega 3 polyunsaturated fatty acids was higher in fisherman than in other populations. There were no differences in dietary compositions of saturated, monounsaturated and polyunsaturated fatty acids among six populations. However, the proportion of dietary omega 3 polyunsaturated fatty acids to total fatty acids varied: 10% for fishermen, 7-8% for farming populations and 6% for urban workers. 2. There were no differences in serum compositions of saturated, monounsaturated and polyunsaturated fatty acids among six populations. However, the proportion of serum omega 3 polyunsaturated fatty acids to total fatty acids varied: 15% for fishermen, 9-10% for farming populations and 8-9% for urban workers. 3. Significant associations were observed between population means of the proportion of dietary and serum polyunsaturated fatty acids. Within each population, individual dietary intake of omega 3 polyunsaturated fatty acids was significantly associated with the proportion of serum omega 3 polyunsaturated fatty acids. Significant associations were also obtained for omega 6 polyunsaturated fatty acids. 4. Fishermen showed a higher population means of dietary and serum omega 3 polyunsaturated fatty acids and a higher incidence rate of cerebral infarction compared with the other populations. This result did not support the hypothesis that dietary and serum omega 3 polyunsaturated fatty acids contribute to prevent cerebral infarction.