Emerging research suggests that plant-forward diets—such as vegan and Mediterranean diets—may help prevent Parkinson’s disease and slow its progression.
Every year in the U.S., nearly 90,000 people are diagnosed with Parkinson’s, a progressive neurodegenerative disorder characterized by motor symptoms like tremors and muscle rigidity, along with non-motor issues such as cognitive decline and mood disorders.
The Gut-Brain Connection: How Parkinson’s May Begin in the Digestive System
Within the past decade, research has indicated that Parkinson’s begins in the gastrointestinal tract and spreads via the vagus nerve, a long cranial nerve, to the brain. This may explain why many patients report gastrointestinal symptoms, such as constipation, years before receiving a Parkinson’s diagnosis.
In light of these discoveries, physicians are increasingly recommending dietary changes as part of Parkinson’s treatment, in addition to prescribing medications. In a new study, published in December 2024 in Neuroscience, researchers compared the neuroprotective effects of various diets—including Mediterranean, vegan, carnivore, paleo, and ketogenic—with regards to Parkinson’s disease.
The study found that the largely plant-based Mediterranean diet showed the greatest promise, correlating with a slower disease progression and lower rate of Parkinson’s occurrence. The vegan diet also appeared beneficial.
How a Plant-Based Diet May Slow Parkinson’s Progression
As noted in the new review, plant-rich diets may help protect against neurodegenerative diseases by lowering oxidative stress and inflammation. Oxidative stress, an imbalance of free radicals and antioxidants in the body, can lead to cell damage and contribute to neuron loss. Meanwhile, inflammation can damage the nerve cells that control movement.
The paper sheds further light on growing awareness of the gut microbiome’s important role in this progressive disease, something even neurologists had not considered until recently, explains Sergio Ramirez-Salazar, M.D., MPH, a cognitive neurologist at Dartmouth Health Medical Center who was not involved in the study.
“Definitely, the diet has a direct role,” Ramirez-Salazar says. “We’ve found that through the vagus nerve, there is a direct connection between the brain and the gut in Parkinson’s.” He adds, “It’s interesting, because [before], we didn’t know the microbiome was playing an important role in not only neurological conditions, but other types of diseases.”
Healthy vegan diets and Mediterranean diets emphasize higher consumption of fruits and vegetables, which are rich in antioxidants, such as vitamins C and E, polyphenols, and carotenoids. These help reduce oxidative stress and support healthy cell function, particularly in the mitochondria, where energy is produced. Additionally, plant-based foods contain compounds that can reduce inflammation, further lowering the risk of cell damage linked to Parkinson’s. Researchers noted that historically, in regions where plant-based diets are common, such as East Asia and sub-Saharan Africa, there are lower rates of Parkinson’s disease.
“What recent studies have shown is that green, leafy vegetables, nuts, seeds, and also tea can help a microbiome prosper,” Ramirez-Salazar says.
On the flip side, the study authors noted that consuming more red and processed meat is associated with an increased incidence of metabolic syndrome, which has been linked to a higher Parkinson’s disease risk. High-protein, meat-heavy diets can interfere with the absorption of carbidopa and levodopa, key medications that help increase dopamine levels and reduce Parkinson’s symptoms like stiffness and tremors.
Furthermore, meat lacks fiber, which is critical for gut motility and microbial balance. As such, constipation, already common among Parkinson’s Disease patients, may be more prevalent among heavy meat eaters.
“I would say every single movement disorder specialist would say try to stay away from a huge carnivore diet because that is going to affect the absorption of the medication,” Ramirez-Salazar says.
Ramirez-Salazar, along with the Parkinson’s Foundation, recommends a whole-food, plant-based diet for individuals who wish to reduce their risk of Parkinson’s and those who have been diagnosed with the disease.
He also emphasizes that diet is just one piece of the puzzle—exercise, sleep, and other lifestyle factors also play a crucial role in managing Parkinson’s. “It’s an interplay,” he says.
