The association between dietary exposures and anxiety symptoms: A prospective analysis of the Australian Longitudinal Study on Women’s Health cohort

BACKGROUND: Nutrition is a potentially modifiable risk factor for mental disorders. Since anxiety is the most common mental disorder globally and most commonly impacts women, understanding its relationship with dietary exposures may elucidate important prevention and treatment approaches. We aimed to explore the association between dietary exposures and incident anxiety in women. METHODS: We used prospective longitudinal dietary data from 20,307 women enrolled in the Australian Longitudinal Study on Women's Health from 1973 to 1978 (young cohort between waves 3-5) and 1946-1951 (mid cohort between waves 3-7). Dietary exposures were defined according to the Global Burden of Disease framework (from wave 3). The primary outcome, anxiety and secondary outcome, depression were measured using subscales of the Goldberg Anxiety and Depression Scale (from wave 4). Generalized estimating equation Poisson regression models estimated risk ratios with 95 % confidence intervals, adjusting for age, socioeconomic status, and energy intake. RESULTS: Higher intakes of vegetables (adjusted risk ratio aRR: 0.94, 95%CI: 0.93-0.96 per serve increase), fruits (aRR: 0.93, 95%CI: 0.92-0.94), nuts and seeds (aRR: 0.93, 95%CI: 0.89-0.98 per serve), milk (aRR: 0.98, 95%CI: 0.96 to 0.99 per serve), fiber (aRR: 0.76, 95%CI: 0.72 to 0.81 per 30-g) and calcium (aRR: 0.88, 95%CI: 0.84 to 0.91 per gram) were associated with lower risk of incident anxiety. Conversely, higher intake of processed meat (aRR: 1.02, 95%CI: 1.00-1.05 per serve) and sodium (aRR: 1.15, 95 % CI: 1.09-1.22 per 2-g) was associated with higher anxiety risk. CONCLUSIONS: Higher intake of plant-based foods and lower intake of processed foods may help reduce the risk of anxiety. Further prospective and intervention studies should confirm these associations and underlying biological mechanisms.