Study Links Tea, Berries and Dark Chocolate to Lower Parkinson's Risk

A diet rich in flavonoid-containing foods may be linked to a modestly lower risk of Parkinson's disease (PD), according to a new study published in Frontiers in Nutrition.

Researchers from China analyzed health and dietary data from 123,655 UK Biobank participants to investigate whether regularly consuming flavonoid-rich foods was associated with developing PD. Flavonoids are plant compounds with antioxidant and anti-inflammatory properties and are found in foods such as berries, citrus fruits, tea, apples, grapes, onions, sweet peppers and dark chocolate.

The researchers assessed participants’ intake of 11 flavonoid-rich foods and identified 796 new hospital-recorded Parkinson’s disease cases during follow-up.

Participants with the highest overall flavonoid diet scores had a lower incidence of hospital-recorded PD compared with those with the lowest scores.

However, researchers did not find a statistically significant protective association for any individual food or flavonoid subclass after accounting for multiple comparisons. The overall association also became weaker after adjusting for coffee consumption, which is independently associated with a lower risk of Parkinson’s disease.

The team additionally explored possible biological pathways using plasma protein and gene-expression data. The exploratory findings pointed toward processes involving immune responses, cell adhesion and transport, with some relevant molecular signatures found in immune cells, microglia and astrocytes. However, no individual protein remained significant after stricter statistical correction, meaning these findings do not establish a specific biological mechanism.

The study was observational, so it cannot prove that flavonoid-rich foods prevent Parkinson’s disease. Dietary information was self-reported, and hospital records may have missed milder cases managed outside hospitals. The participants were also predominantly of European ancestry and generally healthier than the wider population.

The researchers say future studies using diverse populations, repeated dietary measurements and experimental approaches are needed to determine whether flavonoid-rich diets have a causal role in reducing PD risk.

REFERENCE: Yang W, Chen Z, Zhang Y, Peng C, Chen B. 2026. Flavonoid-rich dietary patterns and incident hospital-recorded Parkinson's disease: a prospective UK Biobank study. Frontiers in Nutrition, 13:1893517. DOI: 10.3389/fnut.2026.1893517