Objectives: To examine the association between high intakes of ultra-processed foods (UPF) and recurrence of depressive symptoms (DepS) in a Western non-Mediterranean country and its contribution to the overall diet-depression relationship.
Methods: Analyses were carried out on British participants from the Whitehall II cohort. Present analyses were restricted to white participants N = 4554 (74% men, mean age = 61; SD = 5.9). UPF consumption was estimated from a 127-item food frequency questionnaire using the NOVA classification, and cumulative average of UPF intakes (g/day) over 11 years of exposure (1991/1994-2002/2004) was computed. Recurrent DepS after measurement of UPF was defined as having two or more episodes of DepS (the Center for Epidemiologic Studies Depression Scale (CES-D) score ≥ 16 or antidepressants use) during four phases of follow-up (2002/2004-2015/2016).
Results: Over the follow-up, 588 (12.9%) cases of recurrent DepS were observed. After adjusting for socio-demographic factors, health behaviours and health status, participants in top quintile of UPF intakes [mean 33% of total daily intakes in grams] had 31% higher odds of recurrent DepS (odds ratio 1.31; 95% CI 1.04-1.64) compared to participants in the four lowest quintiles of UPF [mean 18.1% of total daily intakes in grams]. Additional analyses showed that associations between adherence to several diet quality measures and recurrent DepS were partially attenuated (17-27%) by UPF intakes.
Conclusion: In this British population, high intakes of ultra-processed foods were associated with increased odds of recurrent depressive symptoms and contributed to the overall diet quality-depressive symptoms association.
Keywords: Depressive symptoms; NOVA classification; diet quality; nutritional epidemiology; nutritional psychiatry; prospective cohort; ultra-processed foods.