Association of daily fish intake with serum non-high-density lipoprotein cholesterol levels and healthy lifestyle behaviours in apparently healthy males over the age of 50 years in Japanese: Implication for the anti-atherosclerotic effect of fish consumption

Background and aim: Higher fish consumption has been reported to be associated with a lower incidence of coronary artery disease (CAD). We hypothesized that higher fish intake may be associated with lower serum level of non-high-density lipoprotein cholesterol (non-HDL-C) levels, representing the entire dyslipidemia spectrum, and a healthy lifestyle. Methods and results: This cross-sectional study was conducted in a population of 1270 apparently healthy males over the age of 50 years without lipid-modifying therapy at the Health Planning Center of Nihon University Hospital between April and August 2018. The average number of days of fish intake per week was 2.6 ± 1.4. We performed analysis of variance using fish consumption as a categorical variable (0–1 day, 2–3 days, 4–5 days, or 6–7 days per week). The serum non-HDL-C levels in the 6–7 days fish intake group were significantly lower than those in the 0–1 and 2–3days fish intake groups. Furthermore, with increasing frequency of fish intake per week, the proportion of subjects with cigarette smoking decreased (p = 0.026), that of subjects engaging in habitual aerobic exercises increased (p = 0.034), and the sleep duration of the subjects increased (p < 0.0001). Conclusions: These results suggest that a high frequency of fish intake, that is a fish intake of 6–7 days per week, was associated with healthier lifestyle behaviours as well as lower non-HDL-C levels, and thus may represent a component of a healthy lifestyle associated with a lower risk of CAD in Japanese males over the age of 50. Clinical trial registration: UMIN (http://www.umin.ac.jp/). Study ID: UMIN000035899.