Does Fish Oil Reduce the Risk of Cardiovascular Events and Death? Recent Level 1 Evidence Says Yes: PRO: Fish Oil is Useful to Prevent or Treat Cardiovascular Disease

Abstract

Over the past decade there has been a considerable debate whether fish oil supplementation works to prevent and/or treat cardiovascular disease. This is due to the fact that previous studies testing fish oil in Italy and Japan found significant reductions in all-cause mortality, sudden cardiac death, and cardiovascular events, whereas more recent studies have in general been considered negative. We will discuss the reasons for these discrepancies and pave a better path forward when it comes to interpreting studies testing fish oil for the prevention or treatment of cardiovascular disease.

Figure 1

Pooled results from meta-analysis. The figure shows the pooled estimate of relative risk and 95% confidence interval, as well as the number of studies and combined number of participants. CHD, coronary heart disease; CVD, cardiovascular disease; MI, myocardial infarction.

Figure 2

Associations of circulating long-chain n-3 PUFA levels with all-cause mortality: nonlinear dose-response meta-analysis in the Fatty Acids and Outcomes Research Consortium. HR and cohort-specific quantiles are presented in the vertical and horizontal axis, respectively. The best estimates and their CI are presented as black lines and gray-shaded areas, respectively. The 10th percentile was selected as a reference level and the x-axis depicts 5th to 95th percentiles. Potential nonlinearity was identified for EPA (p = 0.0004) but not for the others (p > 0.05). All HRs are adjusted for age, sex, race, field center, BMI, education, occupation, marital status, smoking, physical activity, alcohol intake, prevalent diabetes, hypertension, and dyslipidemia, self-reported general health, and the sum of circulating n-6 PUFA (linoleic plus arachidonic acids).