Male intake of omega-3 fatty acids and risk of intimate partner violence perpetration: a nationwide birth cohort – the Japan Environment and Children's Study

AIMS: Intake of omega-3 polyunsaturated fatty acids (PUFAs) has favourable effects on reducing aggressive and violent behaviours, but its association with perpetration of intimate partner violence (IPV) is not known. We aimed to determine the association between male intake of omega-3 PUFAs and risk of IPV perpetration. METHODS: Participants were male–female pairs in the Japan Environment and Children's Study, in which first pregnant women and then their partners were enrolled (analytic sample: n = 48 065). Male intake of omega-3 PUFAs during the past year (preconception to mid/late pregnancy) was determined using a food frequency questionnaire. IPV (physical violence and emotional abuse) during pregnancy was measured using a self-reported questionnaire completed by pregnant women in mid/late pregnancy. Generalised additive mixed-model analysis was used to examine the non-linear association between energy-adjusted male omega-3 PUFA intake and the adjusted prevalence of male IPV perpetration. RESULTS: A sharply decreasing regression curve was plotted for physical violence, with prevalence starting at 1.35% at the lowest intake level and decreasing to a minimum value of 0.76% at intake of 2.20 g/day (71.7th percentile). However, prevalence largely remained flat from there onward, with the upper limit of the error range not reaching the initial lower limit of the error range until intake exceeded 5.21 g/day (99.77th percentile). For emotional abuse, on the other hand, there was a distorted U- or V-shaped regression curve that rose slightly after reaching a minimum. The prevalence declined from 17.69% initially, reached a minimum at 12.44% at 2.13 g/day (68.3th percentile), and then rose slightly. The lower limit of the error range reached the minimum upper limit at 4.17 g/day (99.1th percentile), and the upper limit finally reached the maximum lower limit value at 4.56 g/day (99.5th percentile). CONCLUSIONS: In this nationwide birth cohort study, higher male intake of omega-3 PUFAs was associated with lower risk of physical violence and emotional abuse perpetration except for extremely high intake. Our results indicate the potential applicability of omega-3 PUFAs in reducing aggressive and violent behaviours in IPV. Trial registration: UMIN000030786.