Low circulating levels of long chain omega-3 polyunsaturated fatty acids (LC omega-3 PUFA) have been linked to major depressive disorder (MDD) and preterm birth (PTB), and prenatal depression associates with PTB. This study hypothesized that low Omega-3 intake would associate with higher MDD and PTB rates on the country-level. Country-level estimates for omega-3 intake, MDD prevalence, PTB rate, and per capita income for 184 countries in 2010 were obtained. Penalized splines indicated that MDD and PTB rates decreased linearly with increasing LC omega-3 PUFA. Adjusted linear regression models revealed that a one standard deviation increase in LC omega-3 PUFA (380 mg/day) was associated with an MDD decrease of 5 cases/1000 people and a PTB decrease of 15 cases/1000 livebirths. Low intake of LC omega-3 PUFA and its precursors may be elevating MDD and PTB rates in 85% of the countries studied.

Timothy H. Ciesielski, Scott M. Williams