Association of platelet count and mean platelet volume with fish intake frequency: Implication for the cardioprotective effect of fish intake

Introduction: Mean platelet volume (MPV) measures platelet activity, and high values indicate increased atherosclerotic cardiovascular disease (ASCVD) risk. Intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) found in fish can lower platelet count (PLC) and platelet activity, potentially reducing the risk of ASCVD. We aimed to investigate the relationship of fish intake with PLC, MPV, and n-3 PUFA intake. Methods: This cross-sectional study was conducted among 9870 participants (average age: 47.5 ± 12.9 years; 55.9% men). N-3PUFA intake was calculated based on fish intake frequency (days/week) and information from the Nutritional Health Survey of Japan. Results: The average fish intake frequency was 2.14 ± 1.26 days/week. As fish intake frequency increased, PLC decreased (p < 0.0001) and MPV increased (< 0.034). Multi-regression analysis showed that PLC was an independent determinant of MPV (β = -0.081, p < 0.0001). Naturally, though, n-3 PUFA intake significantly increased with increased fish intake frequency (p < 0.0001). Conclusion: Higher fish intake was associated with lower PLC and larger MPV. The anti-platelet effect of n-3PUFAs, which intensifies with higher fish intake, may suppress platelet activity with larger MPV. Further studies are required to clarify the causal relationship between these factors.