Dairy intake in relation to metabolic health status, serum levels of brain-derived neurotrophic factor and adropin: a cross-sectional study on Iranian adults

Objective Findings of previous studies on associations between dairy consumption and metabolic health status were inconsistent. This study aimed to assess the link between consumption of dairy foods and metabolic health status, brain-derived neurotrophic factor (BDNF) and adropin levels in adults. Design Cross-sectional. Setting An observational study in Isfahan, Iran. Participants Adults (n=527) selected by multistage cluster random sampling. Dietary intakes were assessed via a validated 168-item food frequency questionnaire. Primary outcome and secondary outcome measures Anthropometric indices, blood pressure and biochemical parameters were assessed. The criteria proposed by Wildman et al were used to categorise participants into metabolically healthy and metabolically unhealthy (MU). Results Participants had a mean age of 42.66 years (45.7% women). Moderate consumption of total dairy was, respectively, linked to 58% lower odds of MU (OR T2 vs T1 =0.42; 95% CI 0.18 to 0.96), after taking all confounders into account. Participants in the middle versus low tertile of low-fat dairy intake showed 51% marginally lower odds of MU (OR T2 vs T1 =0.49; 95% CI 0.22 to 1.08; p=0.08). No significant association was discovered between high-fat dairy intake and MU chance. However, higher total dairy intake was associated with lower odds of hypertension (OR T3 vs T1 =0.36; 95% CI: 0.14 to 0.93). No significant associations were observed between dairy intake and BDNF or adropin levels. Conclusion Moderate consumption of total and low-fat dairy was associated with lower odds of being metabolically unhealthy in Iranian adults, but high-fat dairy intake was not. Hypertension was less common among individuals with higher dairy intake. No association was found between dairy intake and serum levels of BDNF or adropin.