The relationship between dietary lipophilic index and load with depression, anxiety, and stress symptoms

BACKGROUND: Dietary fatty acids can affect brain health by modifying neuronal membrane fluidity. Dietary lipophilic index (LI) and load (LL) may be related to cell membrane fluidity. This study aimed to determine the relationship between dietary LI and LL with symptoms of depression, anxiety and stress. METHODS: In this cross-sectional study, taken from the YaHS (Yazd Health Study) population-based cohort, the data of 2,982 individuals was extracted. Several questionnaires- a 178-item Food Frequency Questionnaire (FFQ), Depression, Anxiety and Stress Scale 21 (DASS 21), and International Physical Activity Questionnaire (IPAQ)- were used to obtain information on dietary intake, mental status, and physical activity, respectively. LI and LL were calculated using dietary intake and the melting point of each fatty acid. RESULTS: The analysis was performed on 2982 individuals. The odds ratio of depression in the second tertile of dietary LI compared to the first tertile was 0.815 (95% CI 0.66–1.00, P = 0.051, P(trend) = 0.017) and after adjusting confounders was 0.793 (95% CI 0.63–0.99, P = 0.043, P(trend) = 0.011). Also, LL was related inversely with anxiety (0.771, 95% CI 0.63–0.93, P = 0.003) that after multiple regression, OR of anxiety was 0.762 (95% CI 0.53–1.07, P = 0.045). The odds of stress in the third tertile of LL was 1.064 but not statistically significant (95% CI 0.88–1.28, P = 0.729). CONCLUSION: This study showed an inverse association between dietary LI and depression symptoms. Anxiety and stress did not show a significant relationship with LI or LL. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12888-023-05161-5.