Ultra-processed foods may double risk of Parkinson's, study reveals

Consuming around a dozen servings of ultra-processed foods a day could more than double your risk of developing Parkinson's disease, a new study suggests.

A single serving in the study was equivalent to 8 ounces of diet or sugary soda, a hot dog, a slice of packaged cake, a single tablespoon of ketchup, or 1 ounce of French fries — a typical bag contains 1.5 ounces.

“Our research shows that eating too much processed food, such as sugary sodas and packaged snacks, may be accelerating the early signs of Parkinson ’s disease,” said senior study author Xiang Gao, distinguished professor and director of the Institute of Nutrition at Fudan University in Shanghai, China, in a statement.

This latest study is part of “growing evidence that diet may influence the development of Parkinson’s disease,” Gao said.

While the study found that people who consumed more ultra-processed foods tended to report more early symptoms, it did not find a direct increase in the risk of Parkinson's disease itself, said Daniel van Wamelen, a clinical senior lecturer in neuroscience at King's College London, who was not involved in the new research.

“The study did not track whether participants were later diagnosed with Parkinson’s,” van Wamelen said in a statement. “That said, having more of these symptoms suggests a higher risk over time.”

The study analyzed years of health and diet data from nearly 43,000 participants in the Nurses' Health Study and Health Professionals Follow-Up Study , two studies in the United States that have been collecting information on health behaviors for decades. The average age of the people in the study was 48, and none had Parkinson's disease at the start of the study. All reported what they ate every few years — a limitation of the new research, as participants may not have accurately remembered their dietary intake.

The ultra-processed foods measured by the study included artificially sweetened or sugary beverages; condiments, sauces and spreads; packaged sweets or desserts; yogurts or dairy desserts; breads and cereals; and packaged savory snacks.

The study found a link between early signs of Parkinson's disease and all types of ultra-processed foods except breads and cereals — a finding that points to an underlying characteristic among most classes of ultra-processed foods that may explain the results, the study said.

One reason could be that ultra-processed foods typically have less dietary fiber, protein and micronutrients — but they contain added sugar, salt and saturated or trans fats, the study said. Ultra-processed foods can also impact the balance of gut flora, while additives can increase inflammation, free radicals and neuronal death, the study found.

“With a sample size of over 42,800 participants and a long follow-up period of up to 26 years, this study stands out not only for its power but also for its methodological rigor,” wrote the authors of an accompanying editorial published with the study.

The editorial was co-authored by Dr. Nikolaos Scarmeas, an associate professor of clinical neurology at Columbia University in New York City, and nutritionist Maria Maraki, an assistant professor of sports medicine and exercise biology at the National and Kapodistrian University of Athens in Greece. Neither of them was involved in the new research.

“Prevention of neurodegenerative diseases can start at the dinner table,” they wrote. “Excessive consumption of ultra-processed foods is not only a risk factor for metabolic diseases, but can also accelerate neurodegenerative processes and associated symptoms.”

First symptoms appear years before the decline in motor function

In the new study, published Wednesday (7) in the journal Neurology, researchers looked at the prodromal stage of Parkinson's disease — early signs that appear years or decades before the tremors, stiff muscles, slow gait and changes in posture that are hallmark symptoms of Parkinson's.

Body aches, constipation, signs of depression, changes in the ability to smell or see colors, and excessive daytime sleepiness can be early signs of Parkinson's disease, according to the Parkinson's Foundation.

An extremely uncommon sleep disorder in which people may move around during REM sleep, or rapid eye movement sleep, is also an important early sign, the research found. The body is normally paralyzed during REM sleep so it doesn't get up and act out during dreams.

The study found that people who consumed about 11 servings of ultra-processed foods a day — compared with people who ate just three — were 2.5 times more likely to exhibit three or more of the early signs of Parkinson’s. He was the first person to be diagnosed with a new sleep disorder. It led to a scientific breakthrough.

Additionally, high consumption of ultra-processed foods was associated with an increased risk for nearly every symptom except constipation, the study found. This finding held true even after the researchers accounted for other factors, such as age, physical activity and smoking, that could impact the results.

“Parkinson’s is an incurable disease,” Gao said in an email. “In our previous study, based on the same populations used for the current analysis, we found that a healthy dietary pattern and physical activity could slow the progression of the disease.”

“Choosing to consume less processed foods and more whole, nutritious foods can be a good strategy for maintaining brain health.”

See also: Advanced therapies help treat Parkinson's