Oily Fish Intake and Cardiovascular Diseases: A Mendelian Randomization Study

Studies have shown a link between oily fish intake and a lower risk of cardiovascular disease (CVD). The potential causal relationship is unclear. The purpose of this study was to investigate the association between oily fish intake and eight CVDs, including coronary heart disease (CHD), heart failure (HF), myocardial infarction (MI), atrial fibrillation (AF), essential primary hypertension (EH), stroke, deep venous thrombosis (DVT), and peripheral artery disease (PDA), through a two-step Mendelian randomization (MR). Genome-wide association study (GWAS) statistics for oily fish intake and CVD were collected from the UK Biobanks and the European Bioinformatics Institute. Single nucleotide polymorphisms (SNP) are used as instrumental variables. In this analysis, the methods for evaluating causality were the inverse-variance weighted, weighted median, and simple median. To evaluate the consistency and dependability of the findings, sensitivity analyses and heterogeneity tests are carried out. MR analysis indicated that genetically predicted oily fish intake is associated with reduced risk of CHD (OR = 0.43, 95% CI, 0.27–0.71, p = 0.0009) and HF (OR = 0.79, 95% CI, 0.65–0.97, p = 0.0245).However, there was no association observed between oily fish intake and MI (OR = 1.00, 95% CI, 0.99–1.01, p = 0.9089), AF (OR = 0.95, 95% CI, 0.79–1.14, p = 0.5475), stroke (OR = 0.99, 95% CI, 0.99–1.00, p = 0.0116), EH (OR = 1.00, 95% CI, 1.00–1.00, p = 0.0009), DVT (OR = 1.00, 95% CI, 0.99–1.01, p = 0.5407), and PAD (OR = 1.00, 95% CI, 0.99–1.00, p = 0.2819). This MR study found a causal connection between oily fish intake and a lower incidence of CHD and HF, but did not affect MI, AF, stroke, EH, DVT, or PAD.