In the past, there has been evidence pointing to a potential link between dairy product consumption and an increased risk of Parkinson’s disease. To prove or disprove this link, the scientists analyzed 25 years’ worth of data from more than 120,000 adults.
Of the 120,000 men and women studied, only a little over 1,000 of them developed Parkinson’s disease. When analyzing the diet habits of these 1,000 Parkinson’s patients, the researchers found that those who consumed low-fat dairy had a significantly higher risk of developing the disorder. In the case of those who consumed three or more servings of low-fat milk/dairy per day, the risk of Parkinson’s was 34% higher than those who only had one daily serving of dairy.
Compared to the adults who drank less than one serving of low-fat dairy per week, the adults who consumed one daily serving of low-fat milk or dairy products had a 39% higher risk of Parkinson’s. Even frozen yogurt and sherbet led to an increase in Parkinson’s risk, albeit a moderate one. On the flip side, the potential danger of full-fat milk caused no increased risk of Parkinson’s disease.
Now, to be clear, the study was intended to be observational, merely discovering the link between low-fat dairy, but not finding the cause of it. Further research is required to determine precisely why low-fat milk could increase Parkinson’s risk. Potential factors include pesticides present in milk and the way low-fat milk affects gut bacteria differently than full-fat milk.
“Our study is the largest analysis of dairy and Parkinson’s to date,” said Katherine C. Hughes, ScD, of the Harvard T.H. Chan School of Public Health in Boston. “The results provide evidence of a modest increased risk of Parkinson’s with greater consumption of low-fat dairy products. Such dairy products, which are widely consumed, could potentially be a modifiable risk factor for the disease.”
It is important to note that the risk of developing Parkinson’s was still very low. Of the 5,830 people who consumed at least three servings per day of low-fat dairy at the start of the study, only 60 people, or 1 percent, developed the disease over the study period. In comparison, of the 77,864 people who consumed less than one serving per day of low-fat dairy, 483 people, or 0.6 percent, developed Parkinson’s.
“Frequently consuming low-fat dairy products was associated with a modest increased risk of Parkinson’s disease,” said Hughes.
One limitation of the study was that early Parkinson’s symptoms may have affected the dietary behaviors and questionnaire responses of study participants.
More research is needed before recommendations can be made about dairy consumption.
1. Katherine Hughes of Harvard Chan School, et al. “Does Consuming Low-Fat Dairy Increase the Risk of Parkinson’s Disease?” American Academy of Neurology. Neurology, Published online 7 June 2017.