Plasma estradiol levels and antidepressant effects of omega-3 fatty acids in pregnant women.

BACKGROUND: Omega-3 polyunsaturated fatty acids (PUFAs) reduce depressive symptoms through an anti-inflammatory effect, and injection of both omega-3 PUFAs and estradiol (E2) induces antidepressant-like effects in rats by regulating the expression of inflammatory cytokines. The aims of this study were to examine the association of increased E2 during pregnancy with depressive symptoms and with inflammatory cytokines in women who were and were not supplemented with omega-3 PUFAs.

METHODS: Pregnant women with Edinburgh Postnatal Depression Scale scores ≥9 were recruited at 12-24 weeks of gestation. The participants were randomly assigned to receive 1800 mg omega-3 fatty acids (containing 1206 mg eicosapentaenoic acid [EPA]) or placebo for 12 weeks. E2, omega-3 PUFAs, high-sensitivity C-reactive protein, interleukin-6, and adiponectin were measured at baseline and at the 12-week follow-up. Multivariable regression analyses were conducted to examine the association of the changes of E2 and omega-3 PUFAs with the changes in depressive symptoms and with the changes of inflammatory cytokines at follow-up by intervention group.

RESULTS: Of the 108 participants in the trial, 100 (92.6%) completed the follow-up assessment including blood sampling. Multivariable regression analyses revealed that the increase of EPA and E2 was significantly associated with a decrease in depressive symptoms among the participants assigned to the omega-3 group, but not among those assigned to the placebo group. Neither E2 nor any PUFAs were associated with a change in inflammatory cytokines.

CONCLUSION: Supplementation with EPA and increased levels of E2 during pregnancy might function together to alleviate antenatal depression through a mechanism other than anti-inflammation.