The purpose of this study is to investigate the effect of habitual oily fish intake, sex, age, BMI, and APOE genotype on plasma long chain n-3 fatty acid composition.

The marine long chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial to cardiovascular and cognitive health and the concentration of EPA and DHA present in blood and tissue lipids is positively correlated with these effects.

As a result, national and global authorities recommend regular consumption of oily fish in order to provide approximately 500 mg EPA+DHA per day in a healthy population. However, the associations between EPA and DHA intake and blood and tissue status, and therefore physiological benefits, are highly variable and the factors influencing this heterogeneity are not well understood.

This study aims to investigate the effect of habitual oily fish intake as well as sex, age, BMI, and Apolipoprotein E (APOE) genotype on LC n-3 PUFA status in plasma phosphatidylcholine, non-esterified fatty acids, cholesteryl esters and triacylglycerols in order to obtain greater knowledge of the determinants of LC n-3 PUFA status with the potential to develop more robust, and perhaps subgroup specific, recommendations for EPA and DHA intake.

Exclusion Criteria:

• Diagnosed endocrine dysfunction including diabetes
• Fasting glucose concentration > 6.5 mmol/L
• Myocardial infarction in the previous 2 years
• The use of medication that may interfere with lipid metabolism
• Fasting total cholesterol of > 8.0 mmol/L
• TG of > 3.0 mmol/L
• Currently following a weight loss diet
• Taking n-3 fatty acid supplements

Individuals residing in Southampton, East Anglia, Glasgow and Newcastle