Does an inflammatory diet affect mental wellbeing in late childhood and mid-life? A cross-sectional study.

Abstract

Inflammatory diets are increasingly recognized as a modifiable determinant of mental illness. However, there is a dearth of studies in early life and across the full mental wellbeing spectrum (mental illness to positive wellbeing) at the population level. This is a critical gap given that inflammatory diet patterns and mental wellbeing trajectories typically establish by adolescence. We examined associations of inflammatory diet scores with mental wellbeing in 11-12 year-olds and mid-life adults. Throughout Australia, 1759 11-12 year-olds (49% girls) and 1812 parents (88% mothers) contributed cross-sectional population-based data. Alternate inflammatory diet scores were calculated from a 26-item food frequency questionnaire, based on prior literature and prediction of inflammatory markers respectively. Participants reported negatively- and positively-framed mental wellbeing via psychosocial health, quality of life and life satisfaction surveys. We used causal inference modelling techniques via generalized linear regression models (mean differences and risk ratios (RR)) to examine how inflammatory diets might influence mental wellbeing. In children and adults respectively, a one standard deviation (SD) higher literature-derived inflammatory diet score conferred between a 44% (RR 95%CI:1.2-1.8) to 57% (RR 95%CI:1.3-2.0) and 54% (95%CI: 1.2-2.0) to 86% (RR 95%CI:1.4-2.4) higher risk of being in the worst mental wellbeing category (i.e. <16th percentile) across outcome measures. Results for inflammation-derived scores were similar. Body mass index (BMI) mediated effects (21-39%) in adults. Inflammatory diet patterns were cross-sectionally associated with mental wellbeing at age 11-12 years, with similar effects observed in mid-adulthood. Reducing inflammatory dietary components in childhood could improve population-level mental wellbeing across the lifecourse.