gms | German Medical Science

Background: Previous investigations have provided evidence supporting a potential risk-increasing link between dairy product consumption and Parkinson’s disease, yet conflicting findings exist. We aimed to determine the relationship between dairy products, dietary calcium and vitamin D intake and the risk of Parkinson’s disease in a large European cohort.

Methods: The present study was conducted among 183,250 participants of the NeuroEPIC4PD cohort, a sub-cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). Data from 12 EPIC centers across 6 European countries were included in the analysis. Dietary intake was assessed at baseline using food-frequency questionnaires and validated through a 24-hour dietary recall (24-HDR) interview. Dietary intakes of calcium and vitamin D were estimated from country-specific databases which were combined in the EPIC Nutrient Database to improve standardization. Non-dietary data was collected using lifestyle questionnaires administered at baseline. The ascertainment of Parkinson’s disease involved a three-step procedure. Cox proportional hazards model was employed in order to examine a potential relationship between baseline dietary intake of dairy, calcium and vitamin D with incident Parkinson´s disease risk.

Results: During a median follow-up time of 17.59 years, 602 incident Parkinson’s disease cases were diagnosed (311 in men, 291 in women) with a median age at diagnosis of 70 years. Baseline dietary intakes of total dairy, yogurt, cheese, calcium and vitamin D were significantly different between men and women, whereas no difference could be observed for milk consumption. After confounder adjustment, no relationship was observed between dairy consumption (highest vs. lowest intake quartile HR 1.07, 95 % CI 0.82-1.39), individual dairy products (milk: HR 0.95, 95 % CI 0.73-1.23; yogurt: HR 1.03, 95 % CI 0.82-1.29; cheese: HR 1.14, 95 % CI 0.86-1.51), or vitamin D (HR 1.07, 95 % CI 0.79-1.45) with Parkinson’s disease risk. However, the present study observed a risk-increasing association with higher vitamin D intakes (HR 1.33, 95 % CI 1.0-1.78, p for trend = 0.031), which was more pronounced in men (HR 1.50, 95 % CI 1.00-2.24, p for trend = 0.045) and in ever smokers (HR 1.64, 95 % CI 1.06-2.53, p for trend = 0.014).

Conclusions: The present study did not find convincing evidence for an association between dietary intakes of dairy products or vitamin D and the risk of developing Parkinson’s disease. However, a positive association between dietary calcium intakes and PD risk in men and in participants ever having smoked was evident. Further high-quality research within comparable as well as different populations is needed in order to verify the associations seen in our study

The authors declare that they have no competing interests.

The authors declare that a positive ethics committee vote has been obtained.