Consuming more than one low-fat but not high-fat dairy product per day was associated with a 35-40% increased risk of developing Parkinson’s disease compared to those that had less than one serving of low-fat dairy.
The overall risk of developing Parkinson’s disease was still quite low. Out of the 5,830 trial participants that consumed low-fat dairy only 1% of developed Parkinson’s. The 77,864 people who consumed less than one serving of low-fat dairy per day only 0.6% developed Parkinson’s disease.
While this is an interesting observation (particularly since the finding was limited to low-fat dairy and not high fat), there is still much more to explore. Since this was not a controlled trial and the study did not control for other confounding factors (since it was looking at baseline characteristics) it is possible that other things associated with low-fat dairy consumption may increase Parkinson’s risk. For example, people that eat low-fat dairy products also may be more likely to consume other low-fat products, many which historically have had transfats in them. More research needs to be done before any conclusions can be made.