Abstract
BACKGROUND: Suicide attempts (SAs) are a major public health issue, with many cases being preventable. However, the impact of dietary patterns remains inadequately studied. Currently, the rising consumption of ultraprocessed foods (UPFs) has been linked to various health issues, including mental health disorders that may increase risk of SA. OBJECTIVES: This study aimed to investigate the association between UPF consumption and SA, and explore the mediating role of SA-related inflammatory index levels. METHODS: This study included 208,938 participants from the UK Biobank cohort, recruited from 2006 to 2010. Cox proportional hazards models were used to assess the association between the weight proportion of UPF intake and incident SA. Substitution analyses were conducted to evaluate risk of SA when replacing UPF with unprocessed or minimally processed foods (UNPFs). Causal mediation analyses were further conducted to estimate the mediating effects of inflammatory index levels in this association. RESULTS: Over a median follow-up of 13.1 y, 545 SA events were identified. Compared with participants in the lowest quintile of UPF consumption, those in the highest quintile had a 1.63 times higher risk of developing SA [hazard ratio (HR): 1.63, 95% confidence interval (CI): 1.23, 2.15]. Additionally, each SD increase in UPF consumption was associated with a 20% higher risk of SA (HR: 1.20, 95% CI: 1.11, 1.29). Notably, replacing 20% of UPF weight with UNPF was linked to a 23% reduction in SA risk (HR: 0.77, 95% CI: 0.69, 0.85). Furthermore, in causal mediation analyses, inflammatory index levels mediated 0.7%-1.5% of the association between UPF consumption and SA. CONCLUSIONS: Higher UPF consumption is associated with an increased risk of SA, partially mediated by inflammatory index levels. Replacing UPF with UNPF significantly reduces SA incidence, highlighting potential benefits of transitioning to a diet with higher UNPF consumption.