Sex, BMI, and APOE4 increase plasma PL-EPA response during an omega-3 fatty acids supplementation: a secondary analysis.

UNLABELLED: The brain is concentrated in omega-3 fatty acids (ω3 FAs) and these FAs must come from the plasma pool. The two main ω3 FAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), must be non esterified (NEFA) or esterified in phospholipid (PL) to reach the brain. We hypothesized that the plasma levels of these ω3 FAs can be modulated by sex, body mass index (BMI), age, and the presence of the apolipoprotein E epsilon 4 allele (APOE4) in response to the supplementation. This secondary analysis aimed to determine the concentration of EPA and DHA within plasma PL and NEFA after an ω3 FAs or a placebo supplementation and to investigate whether the factors change the response to the supplement.

METHODS: A randomized, double-blind, placebo-controlled trial was conducted. Participants were randomly assigned to either an ω3 FAs supplement (DHA 0.8g and EPA 1.7g daily) or to a placebo for six months. Fasting plasma fatty acids were extracted and subsequently separated in PL and NEFA by solid-phase extraction. DHA and EPA levels plasma PL and NEFA were quantified using gas chromatography.

RESULTS: EPA and DHA levels in the NEFA pool significantly increased by 31%-71% and 42%-82%, respectively, after one to 6 months of ω3 FAs supplementation. No factors influenced plasma DHA and EPA responses in NEFA. In the PLs plasma pool, DHA increased by 83%-109%, and EPA by 387%-463% one to 6 months after the ω3 FAs supplementation. APOE4 carriers had higher EPA levels than non-carriers, females had higher EPA levels than males, and individuals with a BMI ≤ 25 kg/m2 had higher EPA than those with a BMI > 25 kg/m2 .

CONCLUSIONS: The concentration of EPA in plasma PLs are modulated by APOE4, sex, and BMI. These factors should be considered when designing clinical trials involving ω3 FAs supplementation.

REGISTRATION NUMBER: NCT01625195 in https://clinicaltrials.gov.