NEW evidence from a large longitudinal cohort suggests that long-term consumption of ultraprocessed foods (UPF) is associated with an increased risk of multiple nonmotor symptoms that often precede a Parkinson’s disease (PD) diagnosis.
The analysis drew on data from over 42,000 participants in the Nurses’ Health Study and the Health Professionals Follow-Up Study who had no history of PD. Dietary intake was assessed repeatedly between 1984 and 2006 using food frequency questionnaires, with UPF intake categorised according to the Nova classification. Participants reported on probable REM sleep behaviour disorder (pRBD) and constipation in 2012. Between 2014 and 2015, a subgroup also reported hyposmia, impaired colour vision, excessive daytime sleepiness, body pain, and depressive symptoms. These seven prodromal features were the primary outcome, analysed cumulatively and categorised as 0, 1, 2, or ≥3 features. Multinomial logistic regression was used to explore associations, adjusting for potential confounders, and logistic regression assessed relationships with individual symptoms.
Of the 42,853 participants included (mean age 47.8 years; 58.6% women), those in the highest quintile of cumulative UPF intake had a significantly greater risk of presenting with three or more prodromal PD features compared to those in the lowest quintile (odds ratio [OR]: 2.47, 95% CI: 1.89–3.23; p-trend<0.0001). The association remained when using baseline intake (OR: 1.50, 95% CI: 1.18–1.89; p-trend=0.0009). Elevated odds were also found for combinations of all features except constipation (OR: 2.00, 95% CI: 1.29–3.11; p-trend<0.0001) and for the classic triad of constipation, pRBD, and hyposmia (OR: 2.47, 95% CI: 1.41–4.34; p-trend=0.008). Higher UPF intake was individually associated with pRBD, constipation, body pain, and depressive symptoms.
These findings support a growing body of research linking diet to neurodegenerative risk and suggest that long-term UPF consumption may contribute to prodromal PD pathology. Reducing UPF intake could offer a modifiable strategy to lower early Parkinsonian risk, though further research is needed to clarify causality.#
Reference
Wang P et al. Long-term consumption of ultraprocessed foods and prodromal features of Parkinson disease. Neurology. 2025;104(11):e213562.
