Study Links Ultra-Processed Foods to Early Parkinson’s Symptoms

A significant new study suggests that high consumption of ultra-processed foods might be associated with early signs of Parkinson’s disease. Researchers followed over 42,000 adults for up to 26 years, discovering that those who consumed 11 or more servings of such foods daily were 2.5 times more likely to exhibit multiple early symptoms of Parkinson’s.

These early indicators included issues with sleep, a diminished sense of smell, depression, and bodily pain, though no link was found with constipation. While the study doesn’t establish a direct cause-and-effect relationship, it reinforces the growing view that diet is crucial for brain health and may influence the risk of neurodegenerative diseases.

Key Findings

• Increased Risk: Participants eating 11 or more servings of ultra-processed food each day were found to be 2.5 times more likely to display early symptoms of Parkinson’s.
• Initial Symptoms: Indicators included sleep problems, reduced smell ability, and signs of depression.
• Dietary Recommendations: The results suggest benefits from reducing ultra-processed food intake to support brain health.

According to the research published in Neurology on May 7, 2025, it appears that individuals who consume more ultra-processed foods, like cold cereals, cookies, and hot dogs, may be more likely to show initial signs of Parkinson’s when contrasted with those who consume them sparingly.

Researchers investigated prodromal Parkinson’s disease, which represents the earliest stage when neurodegeneration begins, yet before more recognizable symptoms, such as tremors and movement difficulties, manifest. It’s interesting to note that these early symptoms can sometimes appear years or even decades prior to the typical manifestations.

“A healthy diet is essential as it can help lower the risk of neurodegenerative diseases. The dietary choices we make can significantly impact our future brain health,” commented Xiang Gao, MD, PhD, from the Institute of Nutrition at Fudan University in Shanghai.

Gao continued, “There’s increasing evidence that dietary habits might affect Parkinson’s disease development. Our findings indicate that high consumption of processed foods, such as sugary beverages and packaged snacks, may accelerate the onset of early Parkinson’s signs.”

The study included 42,853 participants, averaging 48 years of age, who did not have Parkinson’s at the study’s outset, tracking them for up to 26 years. They underwent routine medical exams and completed health questionnaires to identify early signs of Parkinson’s, which included disorders related to sleep, depression, body pain, and more.

For dietary assessment, participants kept a food diary every two to four years, where they recorded their intake of ultra-processed foods, which encompassed sauces, sweets, snacks, artificially sweetened drinks, and various packaged items. One serving was equated to items like a single can of soda, an ounce of chips, or a slice of packaged cake.

Upon analysis, participants were categorized into five groups based on their average daily servings, with the highest group having 11 or more servings, while the lowest group consumed fewer than three servings daily. After accounting for variables such as age and physical activity, it was found that those in the highest consumption group displayed a 2.5-fold increase in the likelihood of showing three or more early Parkinson’s symptoms compared to their counterparts in the lowest group.

Interestingly, while increased consumption of ultra-processed foods correlated with higher risks for nearly all examined symptoms, constipation remained an exception.

Gao added, “Steering clear of processed foods in favor of whole and nutritious options could be a beneficial strategy for maintaining brain health.”

However, it’s worth noting that the study had limitations, mainly that the quantity of ultra-processed food consumed was self-reported, which may lead to inaccuracies in dietary recall.

Funding: The research received support from various organizations, including the National Institute of Neurological Disorders and Stroke and others.