Low-fat dairy, but not whole-/high-fat dairy, consumption is related with higher serum adiponectin levels in apparently healthy adults

Although previous studies suggested that higher low-fat dairy consumption lower the risk of type 2 diabetes, the mediating factors are not well understood. Higher baseline adiponectin levels are related with a lower risk of type 2 diabetes. This study evaluated whether low-fat dairy is related with adiponectin in apparently healthy adults. We investigated a cross-sectional (n = 938) and one-year longitudinal (n = 759) relationship between low-fat and whole-/high-fat dairy (both including cow's milk and yogurt) and adiponectin. Dairy consumption was assessed with a validated food frequency questionnaire. Serum adiponectin was measured by using a specific sandwich enzyme-linked immunosorbent assay. In the cross-sectional analysis, the geometric means (95 % confidence intervals [95 % CIs]) of log-transformed adiponectin related with the low-fat dairy categories were 7.27 (6.80-7.77) for the lowest category, 7.67 (7.09-8.31) for the middle category, and 8.40 (7.73-9.13) for the highest category (p < 0.001) after adjustment for potential confounders (including all lifestyle factors). In the longitudinal analysis, repeated-measures ANCOVA adjusted for confounding factors showed a significant time-by-categories (categories of low-fat dairy) interaction in the change of adiponectin. In contrast, no significant relationship was found between the whole-/high-fat dairy categories and adiponectin. This study has shown that higher consumption of low-fat dairy, but not of whole-/high-fat dairy, is related with higher levels of adiponectin and with the change of adiponectin level at the one-year follow-up. These results suggest that the consumption of low-fat dairy may have a beneficial effect on serum adiponectin levels.