Though a large study published in the journal Neurology, researchers have shown that consuming at least three servings of low-fat dairy a day is associated with a greater risk of developing Parkinson’s disease compared to consuming less than one serving a day. Researchers also found that drinking more than one serving of low-fat or skim milk per day is associated with a greater risk of developing Parkinson’s disease compared to drinking less than one serving per week.
Scientists are quick to warn that their findings do not suggest that dairy products are responsible for Parkinson’s disease, but their study indicates an association between the two and more study is required to establish a greater association and possible a cause relation.
Researchers analyzed approximately 25 years of data on 80,736 women enrolled in the Nurses’ Health Study and 48,610 men enrolled in the Health Professionals’ Follow-up Study. During the course of the study 1,036 people developed Parkinson’s.
Researchers examined what kinds of dairy each person consumed, including milk, cream, cheese, yogurt, ice cream, butter, margarine and sherbet. They then looked at whether full-fat dairy, as whole milk, was associated with a risk of Parkinson’s disease; there was no association. However, those who consumed at least three servings of low-fat dairy a day had a 34 percent greater chance of developing Parkinson’s than people who consumed less than one serving per day.
The study also found that in case of people who consumed skim and low-fat milk, there was a 39 percent greater chance of developing Parkinson’s for people who consumed more than one serving per day compared to those who consumed less than one serving per week. Eating sherbet or frozen yogurt also was linked to a modest increased risk.
In a meta-analysis, looking at a group of studies, the researchers found that total dairy intake was associated with an increased risk of Parkinson’s disease. The overall conclusions from these studies was that frequent consumption of dairy products was associated with a modest increased risk of Parkinson’s disease.
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.