Reacción a "Study suggests eating ultra-processed foods may accelerate early Parkinson's symptoms"

Firstly, the outcome term 'early symptoms of Parkinson’s disease' is a bit misleading as symptoms such as constipation, and body pain here found to be associated with consumption of Ultra Processed Foods (UPF) are quite common in ageing and are not necessarily indicative of Parkinson’s disease.
 
Even the most likely predictor of Parkinson’s disease – probably REM sleep disorder – is seen in 65% of Parkinson patients but also in 10% of controls, with low (65%) sensitivity for Parkinson's disease, even when people already have this disease (Kakazu, 2024). This symptom only shows relations with the highest intake of UPF.
 
Other symptoms like reduced sense of smell, daytime sleepiness, impaired colour vision and depression by themselves seem not related to consumption of UPF.
 
With regards to the UPF outcome, 30% of food consumption assessed by questionnaire was not agreed on and while experts apparently re-assessed these, it is not clear how they agreed on categorisation of foods, so whether they were UPF or not.
 
It seemed strange that non-UPF food included beef, pork, lamb chicken or turkey sandwich (all processed meats); cream; pancakes or waffles; pie, home-baked or readymade; popcorn; potato or
corn chips; soy milk; and tomato sauce, as well as distilled alcohol and dairy coffee.
 
Individual foods such as UPF breads or cereals and indeed microwaveable meals were by themselves not associated with the 'early Parkinson disease symptoms' while sauces, sweets, artificial sweetened drinks and desserts were as well as savoury snacks, animal and dairy products including yogurts.  Such foods are associated with diabetes mellitus and vascular (heart) disease, respectively, which can impact on brain disease because of their sugar and trans fat contents, respectively.
 
However, it is not the first study to show associations of UPF and brain disease.  We early wrote a piece on studies investigating dementia risk and processed meat consumption.  A healthy varied whole food diet is associated with prevention of many diseases including dementia.
 
Lastly, these two cohorts were mainly white health professionals so the results do not necessarily translate to everyone.
 
So this study may be affected by UPF categorisation as a predictor, where also not all UPF foods showed an association; the limited study group associations were assessed in (only mainly white health professionals and nurses) and also by the outcome, as these symptoms are not necessarily predictive of Parkinson’s disease, nor were these symptoms individually all associated with UPF consumption.