Combined Higher Frequency Fish Consumption and Healthy Lifestyle May Lower the Triglyceride/HDL-C Ratio in Middle-Aged Japanese Males: Anti-Atherosclerotic Effect of Fish Consumption

Background: Fish consumption may be associated with a low risk of coronary artery disease. We aimed to investigate whether higher fish consumption results in improved lifestyle behaviors and thus lower triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratio - a predictor of atherosclerotic cardiovascular disease (ASCVD). Methods and Results: This cross-sectional study included 2,947 middle-aged Japanese males with no history of ASCVD or lipid-modifying therapy, who presented at the Health Planning Center of Nihon University Hospital between April 2018 and March 2019. We performed an analysis of variance using fish consumption as a categorical variable (0-2 days, 3-4 days, or 5-7 days per week). The serum TG/HDL-C ratio in the 5-7 days fish consumption group was significantly lower than those in the 0-2 and 3-4 days fish consumption groups (p < 0.0001 and p < 0.01, respectively). Multiple regression stepwise analysis revealed that weekly fish consumption negatively and independently determined the TG/HDL-C ratio (β = -0.061, p = 0.001). As fish consumption increased, the proportion of subjects with smoking habits decreased (p = 0.014), those engaging in aerobic exercises and aggressive daily physical activity increased (p < 0.0001 for both), and those with alcohol habit increased (p < 0.0001). In addition, we developed the risk stratification for ASCVD by combining the serum HDL-C level and the serum TG/HDL-C ratio with fish consumption. Conclusion: Increased frequency of fish consumption and improved lifestyle behaviors due to daily fish intake may work additively to lower the serum TG/HDL-C ratio. These associations may explain why high fish consumption is associated with a lower risk of ASCVD. Our findings may help physicians and nutritionists in treating patients with heart diseases and metabolic conditions by recommending a high fish diet in middle-aged Japanese males.