Ultra-processed foods (UPF) have been subject to heavy criticism over the past decade, with many consumers now believing they’re damaging to health and the environment.
This is further exacerbated by the World Health Organization likening their consumption to smoking and drinking alcohol.
And added to that, the food and beverage industry has failed to sway public opinion back in UPF’s favour.
Now, scientists have found further evidence to suggest ultra-processed foods are damaging to health.
Could ultra-processed foods cause Parkinson’s disease?
Research, published in Neurology, found that people who eat a diet high in ultra-processed foods may be more likely to develop early signs of Parkinson’s disease.
The study did not prove that ultra-processed foods directly cause Parkinson’s. Instead, it showed a strong link between a high intake of these foods and beverages, and early warning signs of the disease.
What is Parkinson's disease?
Parkinson's disease is a progressive brain disorder caused by a loss of nerve cells in part of the brain.
Symptoms include shaking (tremors), slow movements and stiffness.
Current treatments for Parkinson's disease include therapies to aid movement, medication, and in some cases surgery.
Scientists focused on what’s known as prodromal Parkinson’s disease. This is the earliest phase of the condition, when subtle changes in the brain begin to take place, but symptoms such as tremors, balance issues, and slowed movement have not yet begun. Early signs can develop for years before a diagnosis is made.
“Eating a healthy diet is crucial as it has been associated with a lower risk of neurodegenerative diseases and the dietary choices we make today can significantly influence our brain health in the future,” says study author Dr Xiang Gao. “There’s growing evidence that diet might influence the development of Parkinson’s disease. Our research shows that eating too much processed food, like sugary sodas and packaged snacks, might be speeding up early signs of Parkinson’s disease.”
The research team followed 42,853 people, with an average age of 48, over a 26-year period. Participants did not have Parkinson’s disease at the beginning of the study. They had regular medical exams and completed health questionnaires.
Researchers reviewed the results to determine if anyone was showing early signs of Parkinson’s, including rapid eye movement sleep behavior disorder, constipation, depressive symptoms, body pain, impaired colour vision, excessive daytime sleepiness, and reduced ability to smell.
All those taking part completed a food diary every two-to-four years, listing what they ate and how often.
What are ultra-processed foods?
The researchers categorised ultra-processed foods as:
- Sauces, spreads, and condiments
- Packaged sweets, snacks, and desserts
- Artificially or sugar-sweetened beverages
- Processed meat and fish products
- Yoghurt or dairy-based desserts
- Packaged savoury snacks
Researchers then calculated each participant’s average daily intake of these foods.
Participants were then divided into five groups. The highest group ate 11 or more servings of ultra-processed food per day on average, while the lowest group ate an average of fewer than three servings per day.
After adjusting for factors such as age, physical activity and smoking, researchers found that participants who ate 11 or more servings of ultra-processed foods per day had a 2.5 times higher chance of having three or more early signs of Parkinson’s disease, compared to those consuming fewer than three servings per day.
When looking at individual early signs of Parkinson’s disease, researchers also found that eating more ultra-processed foods was tied to an increased risk for nearly all symptoms, except constipation.
“Choosing to eat fewer processed foods and more whole, nutritious foods could be a good strategy for maintaining brain health,” said Dr Gao. “More studies are needed to confirm our finding that eating less processed food may slow down the earliest signs of Parkinson’s disease.”
The research team highlighted that the study was limited by the fact that food intake was self-reported, leaving room for inaccuracies.
What does this mean for food and beverage?
The food and beverage industry is at somewhat of a crossroads. On the one hand shelf life, food security, and affordability are all major benefits to processing methods. But on the other, mounting health concerns are increasingly scaring shoppers.
So, which route will manufacturers choose? Will they stick to their guns and risk losing customers to health fears or will they reformulate now and pay the literal price in increased production costs?
The weight of opinion seems to be moving towards acting now.
“With so many different and often short-lived health trends currently bouncing around on social media, it would be tempting to think that the current UPF furore will also quickly die down,” says Alice Pilkington, senior global food and drink analyst at Mintel. “However, that many Europeans do not think it’s just another healthy eating fad, demonstrates the need for food and drink brands to take this seriously. Indeed, it would be arguable that the UPF focus marks a watershed moment for the industry.”
But there is also the need for better consumer education on the different types of ultra-processing methods and their effects, and this must come from the industry. One of the reasons so many consumers have a negative view of all ultra-processed foods is because the industry has failed to effectively communicate the reasons they exist in the first place.
“There is a wide and confusing array of information on ultra-processed food, some of which is conflicting and some that is simply misinformation,” says Klaus Grunert, director of EIT Food Consumer Observatory. “To compound this issue, there is no sector-wide consensus on what foods constitute as UPF, how to include UPF into a balanced diet, and what processing levels relate to the overall healthiness of a product. This is leaving consumers without the information they need on which foods are healthy and which they should avoid, preventing them from making informed choices.”
Source: Neurology “Long-Term Consumption of Ultraprocessed Foods and Prodromal Features of Parkinson Disease”. Published Date: 7 May 2025. DOI: 10.1212/WNL.0000000000213562. Authors: Peilu Wang, Xiao Chen, Muzi Na, Mario H Flores-Torres et al.
