Ultra Processed Foods Linked To Early Parkinson’s Signs

Consuming ultra-processed foods, including cold breakfast cereals, cookies, and hot dogs, can increase the risk of early Parkinson's disease symptoms, suggests a study released on May 7, 2025, in Neurology, the American Academy of Neurology's medical journal. The study does not confirm a cause-and-effect link but finds a significant correlation between increased consumption of ultra-processed foods and the occurrence of prodromal Parkinson's disease symptoms.

Prodromal Parkinson's disease is the initial phase of the condition, in which neurodegeneration begins but the typical symptoms such as tremors, balance, and slowness have yet to emerge. These preliminary signs may occur years or even decades prior to the more apparent signs of Parkinson's. Researchers wanted to investigate the relationship between diet and the onset of these early signs of Parkinson's disease.

Dr. Xiang Gao, lead author of the study and a scientist at the Institute of Nutrition at Fudan University in Shanghai, stressed the significance of a healthy diet in preserving brain function and lowering the risk of neurodegenerative diseases. He noted that mounting evidence indicates that diet may have a major role in the onset of Parkinson's disease. Gao cautioned that excessive consumption of processed food, including sugary drinks and packaged snacks, may be hastening the early symptoms of the disease.

The research included 42,853 participants, all of whom were Parkinson's disease-free at the start of the study. The volunteers, whose average age was 48, were monitored for as long as 26 years. Throughout the study, they had routine medical checkups and filled out health questionnaires. Investigators assessed whether subjects showed early features of Parkinson's disease, including rapid eye movement (REM) sleep behavior disorder, constipation, depression, pain in the body, impaired color vision, excessive daytime somnolence, and decreased ability to smell.

Participants also completed food diaries every two to four years, recording their diet and how often they ate. The scientists were interested in a number of ultra-processed food groups, including condiments, sauces, and spreads; sweets and snack foods packaged; artificially or sugar-sweetened drinks; animal-based foods; dairy- or yogurt-based desserts; and packaged savoury snacks. One serving corresponded to one can of soda, an ounce of potato chips, a piece of packaged cake, a single hot dog, or a tablespoon of ketchup.

Participants were stratified into five groups according to the average daily servings of ultra-processed foods. The highest group had 11 or more servings per day, and the lowest group had less than three servings per day. After adjusting for several factors including age, physical activity, and smoking status, the researchers found that those who ate 11 or more servings of ultra-processed foods per day had a 2.5-fold increased risk of having three or more early signs of Parkinson's disease than those who consumed fewer than three servings per day.

In addition, the research discovered that increased ultra-processed food intake was linked to higher risk of almost all the prodromal signs of Parkinson's disease, with the only exception being constipation. This could indicate that cutting down on processed food can slow the early development of the disease, but further research is required to validate these findings.

Dr. Gao suggested replacing fewer processed foods with whole, healthy options in order to induce greater brain health. He noted that further study is needed before it can be concluded that consuming fewer processed foods may delay the onset of Parkinson's disease.

One of the study limitations is that the participants self-reported what they ate, so the data could be subject to error through imperfect recall or food-reporting bias. Notwithstanding this, the research indicates a possible risk of eating a great deal of ultra-processed foods and its potential association with neurodegenerative disorders.

The study was funded by the National Institute of Neurological Disorders and Stroke, Shanghai municipal public health system, the National Natural Science Foundation of China, and the China Postdoctoral Science Foundation.

Parkinson's disease is a neurodegenerative movement disorder that presents with symptoms such as tremors, rigidity, and bradykinesia (slow movement). It occurs slowly and becomes more apparent with advancing age, even though the initial signs may appear much sooner. This study highlights diet as an element which could play a role in causing Parkinson's disease, citing increasing evidence of a link between what is eaten and brain function.

For further information regarding Parkinson's disease, as well as resources for caregivers and patients, the American Academy of Neurology provides educational resources via their Brain & Life® platform, including a magazine, podcasts, and expert tips on brain health. The American Academy of Neurology, the largest association of neurologists and neuroscience professionals globally, promotes progress in brain health and insight into neurological illness like Parkinson's disease.

This research is a significant step toward understanding the possible role of diet in Parkinson's disease, but more research is needed to completely understand how dietary habits may affect the early stages and progression of the disease.