Omega-3 polyunsaturated fatty acid intake norms and preterm birth rate: a cross-sectional analysis of 184 countries. Issue 4 (20th April 2019)

• Record Type: Journal Article
• Authors: Ciesielski, Timothy H; Bartlett, Jacquelaine; Williams, Scott M
• Is Part Of: BMJ open. Volume 9:Issue 4(2019)
• Publication Date: 2019-04-20
• Subjects: diet -- omega-3 -- poly-unsaturated-fatty-acid -- preterm birth -- prevention -- food systems; Medicine -- Research -- Periodicals; 610.72
• DOI: 10.1136/bmjopen-2018-027249
• Languages: English
• ISSNs: 2044-6055

Abstract

Abstract : Background: The preponderance of evidence now indicates that elevated long-chain omega-3 polyunsaturated fatty acid (LC omega-3 PUFA) intake is often associated with reduced risk of preterm birth (PTB). This conclusion is based on recent meta-analyses that include several studies that reported null findings. We probed the reasons for this heterogeneity across studies and its implications for PTB prevention using country-level data. Methods: We analysed the relationship between national PTB rates (<37 weeks of gestation) and omega-3 PUFA intake norms from 184 countries for the year 2010. To estimate the total LC omega-3 PUFA levels (eicosapentaenoic acid [EPA]/docosahexaenoic acid [DHA]) that these norms produce we utilised a metric that accounts for (1) seafood-based omega-3 intake (EPA/DHA) and (2) plant-based omega-3 intake (alpha-linolenic acid [ALA]), ~20% of which is converted to EPA/DHA in vivo. We then assessed the shape of the omega-3–PTB relationship with a penalised spline and conducted linear regression analyses within the linear sections of the relationship. Results: Penalised spline analyses indicated that PTB rates decrease linearly with increasing omega-3 levels up to ~600 mg/day. Income-adjusted linear regression analysis among the countries in this exposure range indicated that the number of PTBs per 100 live births decreases by 1.5 (95% CI 2.8 to 0.3) for each 1 SD increase in omega-3 intake norms (383 mg/day). Conclusions: Taken with prior evidence for a causal association on the individual level, our findings indicate that omega-3 PUFA deficiency may be a widespread contributing factor in PTB risk. Consideration of baseline omega-3 PUFA levels is critical in the design of future interventions.