Effects of a Fish-Based Diet on the Serum Adiponectin Concentration in Young, Non-Obese, Healthy Japanese Subjects

Aim: Adiponectin has insulin-sensitizing, anti-atherogenic, and anti-inflammatory properties, and researchers have recently reported that omega-3 polyunsaturated fatty acid (PUFA) can increase the serum adiponectin concentration, suggesting that dietary factors, such as fish intake, may have an influence on the serum adiponectin concentration. In general, Japanese subjects consume twice as much fish as people in other countries. We hypothesized that incremental change in serum omega-3 PUFA levels by fish intake is an important regulator of serum adiponectin even in Japanese subjects. The aim of this study was to explore the relationship among fish consumption, serum omega-3 PUFA, such as eicosapentaenoic acid (EPA), levels, and serum adiponectin levels. Method: We recruited 17 healthy Japanese volunteers (seven men and 10 women) for an 8-week fish-diet intervention (omega-3 PUFA 3.0 g/day) without affecting total energy intake, and measured serum adiponectin concentration and fatty acid profiles. Results: Fish-diet intervention significantly increased the serum adiponectin concentration in women (from 13.5 +/- 4.6 to 15.8 +/- 5.2 mu g/mL, p < 0.01) but not in men (from 8.7 +/- 2.8 to 8.7 +/- 2.5 mu g/mL). Serum omega-3 PUFA increased more in female subjects than male subjects after the fish-diet intervention (57.3 +/- 86.6 vs 150.9 +/- 46.7 mu g/mL, p = 0.011), suggesting that changes in omega-3 PUFA concentration may explain the different response between sexes. Conclusion: A fish-based diet intervention increased the serum adiponectin concentration in young, non-obese, healthy Japanese female subjects. The increment in serum omega-3 PUFA may regulate the serum adiponectin concentration.