Changes in the Eicosapentaenoic Acid to Arachidonic Acid Ratio in Serum over 10 Years in a Japanese Community: The Hisayama Study

Aim: Circulating omega-3 and omega-6 polyunsaturated fatty acids may to contribute to cardiovascular health at the population level. Over a decade, we investigated changes in the serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio, and in serum concentrations of the individual fatty acids, in a Japanese community. Methods: Community surveys took place in 2002-2003 and 2012-2013 in a rural area of Japan. The community surveys included 3,194 and 3,220 community dwellers aged >= 40 years who did not take EPA medication in 2002-2003 and 2012-2013, respectively. Fatty acid fractionations in serum were measured using a gas chromatography method. Changes in the serum EPA/AA ratio over time were examined using linear mixed models. Results: Overall, the average serum EPA/AA ratio decreased over the 10 years. A decreasing trend in the serum EPA/AA ratio occurred in all age groups except participants aged >= 80 years, with larger decreases in the younger age groups. A similar decline in serum EPA/AA ratio occurred in participants with and those without lipid -lowering therapy. Serum EPA concentrations were slightly increased in the whole population but remained stable or even decreased in participants aged 40-69. In contrast, the average serum AA concentrations increased in all age groups. Conclusion: In a Japanese community, the serum EPA/AA ratio decreased over 10 years at the population level, especially in middle-aged participants.