In 2025, X. Zhang and a team analyzed 467,200 adults aged 37–73 from the UK Biobank, tracking them for Parkinson’s disease (PD). They defined metabolic syndrome (MetS) as having at least three of: big waist (≥40 inches men, ≥34.6 inches women), high blood pressure, low HDL cholesterol, high triglycerides, or high blood sugar. They checked medical records for 3,222 PD cases.

Researchers at the University of the Basque Country (2025) have discovered that saliva contains hundreds of DNA methylation markers linked to major diseases—including cancer, coronary artery disease, type 2 diabetes, and Parkinson’s.