Dietary Phytochemical Index in Relation to Metabolic Health Status, Serum Adropin, and Brain-Derived Neurotrophic Factor Levels in Adults

BackgroundLittle is known about the relationship between dietary intake of phytochemicals with metabolic health status and underlying mechanisms. We hypothesized that dietary phytochemical index (DPI) improves metabolic health status by ameliorating serum levels of brain-derived neurotrophic factor (BDNF) and adropin.MethodsA cross-sectional study was performed on 527 adults (286 males and 241 females). Dietary intakes of participants were collected by a 168-item food frequency questionnaire and DPI was estimated as percentage of energy intake derived from phytochemical-rich foods. Anthropometric variables, blood pressure, glycemic and lipid profiles, and biochemical variables were assessed. The metabolically unhealthy (MU) phenotype was determined based on the definition presented by Wildman et al.ResultsThe MU phenotype was identified in 51.4% of male and 32.0% of female participants. Participants in the third tertile of DPI had 59% lower odds of MU compared to those in the first tertile (OR=0.41, 95% CI: 0.19-0.87), after considering potential confounders. Stratified analysis by sex and body mass index indicated that DPI was inversely related to MU phenotype in females (OR=0.28, 95% CI: 0.08-0.97) and normal-weight individuals (OR=0.11, 95%CI: 0.02-0.62). PDI was also inversely associated with hyperglycemia, hypertriglyceridemia and chronic inflammation. Non-significant reduced odds of low BNDF (OR=0.87, 95%CI: 0.42-1.84) and adropin (OR=0.75, 95%CI: 0.31-1.79) were observed in individuals in the top tertile of DPI compared to those in the bottom tertile.ConclusionThis study showed that individuals with higher dietary intake of phytochemicals had lower odds of MU, particularly females and normal-weight individuals. No significant relationship was observed between serum BDNF and adropin with phytochemical intake.