Omega-3 polyunsaturated fatty acid supplementation and the risk of fatal myocardial infarction among Norwegian women: a prospective cohort

Abstract

<p>Background: In 2015, around 17.9 million people died from cardiovascular disease worldwide, with myocardial infarction being the most common manifestation. Contemporary research suggests that omega-3 (n-3) polyunsaturated fatty acid (PUFA) interventions have less useful cardiovascular outcomes than previously thought. This study aims to examine the association between n-3 PUFA intake frequency and the risk of fatal myocardial infarction (FMI) by using food frequency questionnaires and adjust for confounding factors. <p>Method: The Norwegian Women and Cancer (NOWAC) study is a population-based cohort that utilizes self-reported data obtained from already existing population registries and questionnaires, in which four out of a total of eight pages contained questions regarding dietary habits. Data from 101,316 eligible Norwegian women (mean age: 52.24 years, range: 41–76 years) were analyzed. A total of 22,395 subjects were excluded according to predefined criteria, such as prevalent disease. Data on FMI were obtained from the Norwegian Cause of Death Registry. The participants were divided into three n-3 PUFA intake frequency groups: never, intermittent, and daily. The relationship between n-3 PUFA supplement intake and FMI was assessed using a Cox proportional hazards model. A stratified model was constructed according to the median intake of fatty fish (11 g/day) to assess the separate effect within groups of high and low fatty fish intake. <p>Results: Over an average of 18.41 years of follow-up, 256 cases of FMI were reported. The crude incidence rate was found to be 17 per 100,000, and a nonsignificant inverse association was observed. The estimates for intermittent and daily intake (compared to never) according to the multivariate-adjusted model were respectively hazard ratios (HRs) of 0.95 (95% confidence interval [CI]: 0.72-1.26) and 0.85 (95% CI: 0.60-1.20). The estimates of the association between n-3 PUFA supplement intake and FMI among those with low intake of fatty fish, according to the multivariate-adjusted model, were an HR of 0.65 (95% CI: 0.39– 1.09). Hence, the multivariate-adjusted model was statistically insignificant. <p>Conclusions: More frequent intake of n-3 PUFA supplements is not associated with a lower risk of FMI among women in the NOWAC study.