A new study has raised serious concerns about a staple of modern diets: ultraprocessed foods.

According to researchers, consuming high amounts of these everyday convenience items may significantly increase the risk of developing early signs of Parkinson’s disease—a progressive neurological condition that affects movement.

The large-scale study, published Wednesday in the journal Neurology, tracked over 42,000 participants for up to 26 years. Scientists found that people who consumed 11 or more servings of ultraprocessed food daily were 2.5 times more likely to show early Parkinson’s symptoms than those who consumed three or fewer servings.

Even those who consumed just three servings per day had a 60% higher risk, depending on the type of food. One serving is defined as one can of soda, one hot dog, a tablespoon of ketchup, or a slice of packaged cake.

“Eating too much processed food, like sugary sodas and packaged snacks, might be speeding up early signs of Parkinson’s disease,” said study author Dr. Xiang Gao of Fudan University in China.

Ultraprocessed foods (UPFs) include packaged sweets, sodas, savory snacks, processed meats, sauces, and even some items often mistaken for healthy choices, like pre-packaged salads or sliced meats.

The early symptoms tied to these foods include sleep issues, fatigue, constipation, depression, and a reduced sense of smell. While subtle, these signs can occur decades before diagnosis and may signal changes in the brain’s ability to produce dopamine, the neurotransmitter responsible for movement.

The study’s authors suggest that artificial additives—like emulsifiers, sweeteners, and preservatives—may promote inflammation and oxidative stress, which damage dopamine-producing neurons. These additives can also disrupt the gut microbiome, leading to further inflammation in the brain. “Choosing to eat fewer processed foods and more whole, nutritious foods could be a good strategy for maintaining brain health,” Dr. Gao advised.

Outside experts have urged caution, emphasizing that the study does not prove a direct link between UPFs and Parkinson’s disease diagnoses.

“The symptoms examined… are possible early signs of Parkinson’s disease, not definitive indicators,” said Dr. Daniel van Wamelen, a neurologist at King’s College London. “Many of these symptoms, like constipation or sleep problems, are also common in the general population.”

Another limitation? Participants self-reported their food intake, which may not have been entirely accurate.

“People often inaccurately self-report what their diet comprises,” noted Dr. Katherine Fletcher of Parkinson’s UK. “The study group also lacked ethnic and socio-economic diversity, which is vital when studying health risks.”

Still, the study adds to growing evidence that diet plays a powerful role in brain health.

Parkinson’s affects nearly 90,000 Americans each year and 18,000 people annually in the UK, primarily those over 45. While aging and environmental toxins are known contributors, lifestyle choices like diet and smoking are increasingly under scrutiny.