Abstract
BACKGROUND: Several studies have investigated the effects of dietary one-carbon metabolism (OCM) nutrients, such as methionine, folate, vitamin B6, and vitamin B12, on Parkinson's disease (PD). However, current evidence remains insufficient to definitively establish a link between OCM intake, PD incidence, and genetic risk.</p>
METHODS: Among 202171 individuals aged 37-73 in the UK Biobank, we assessed dietary OCM nutrient intake via repeated 24-hour recalls, determined PD incidence via validated ICD-10 codes, and quantified genetic risk with polygenic risk scores. Employing Cox proportional hazards models supplemented by sensitivity analyses, we evaluated the associations and potential interactions among OCM nutrient intake, genetic risk, and PD incidence.</p>
RESULTS: Over a median 12.27-year follow-up of 202171 participants, 1037 incident PD cases occurred. In multivariable-adjusted Cox models, compared with participants in the lowest quartile, those in the highest quartile of methionine, vitamin B6, folate, and vitamin B12 had a lower risk of PD [HR (95% CI)=0.83 (0.69-1.00), 0.75 (0.62-0.90), 0.71 (0.59-0.85), and 0.79 (0.65-0.94)]. Genetically-stratified analyses showed folate inversely associated with PD risk in the low-risk group [HR (95% CI)= 0.65 (0.48-0.88)] (P for interaction = 0.48); vitamin B12 linked to lower risk in the high-risk group [HR (95% CI)= 0.78 (0.63-0.99)] (P for interaction = 0.83); and vitamin B6 inversely associated across both strata [high-risk HR (95% CI)= 0.77 (0.62-0.97); low-risk HR (95% CI) = 0.59 (0.44-0.80)](P for interaction = 0.08).</p>
CONCLUSIONS: Higher OCM nutrient intake might be inversely associated with PD risk. However, evidence regarding the independent contributions of dietary and genetic factors remains inconclusive.</p>