Eating sweets, red meat may raise risk of Parkinson’s, study finds
But stronger links seen for nondietary influences like family history
Frequently eating sweets, red meat, and processed meats appears to increase the risk of developing Parkinson’s disease, while consuming more fruits — especially citrus — may be protective against it, according to a large study from Italy.
The researchers found, however, that certain nondietary influences were more strongly linked to the risk of Parkinson’s than eating habits. Key among these, the team noted, were family history, digestive problems, and exposure to pesticides, oils, metals, and general anesthesia.
“This study suggests that eating habits might have some impact on [Parkinson’s disease], but they are not the main cause,” the scientists wrote. “Future research should look at both diet and other lifestyle habits to better understand how to prevent [Parkinson’s].”
The study, “The impact of diet on Parkinson’s disease risk: A data-driven analysis in a large Italian case-control population,” was published in the Journal of Parkinson’s Disease.
“Scientists are still studying what causes [Parkinson’s disease], and some think that diet might play a role,” the team wrote. “In our study, we looked at how different eating habits might be linked to [Parkinson’s].”
Eating a healthy diet is widely known to support overall well-being, and growing evidence suggests that it may help ease symptoms and slow disease progression in people with Parkinson’s.
Study sought to link specific foods, not diets, to Parkinson’s risk
However, while several studies have examined the effects of different eating plans, such as the Mediterranean diet or the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND), none have clearly identified specific foods that might increase or reduce the risk of developing Parkinson’s.
Seeking to fill that gap, researchers from institutions across Italy conducted a large survey at six neurology centers across the country between September 2018 and September 2019. Their goal was to identify distinct foods possibly linked to Parkinson’s risk and to compare their impact with that of established disease risk factors.
The study involved 680 people with Parkinson’s disease and 612 healthy individuals, who served as controls. The mean age of the Parkinson’s patients was 67.9, while the healthy controls were, on average, 64.4 years old. Slightly more than half of the individuals in both groups were men, and overall, the two groups had a comparable body mass index (BMI), a measure of body fat based on height and weight.
All participants were asked to report how often they consumed 77 common foods — from fruits and vegetables to meats, sweets, and beverages — to capture their usual eating habits before Parkinson’s symptoms appeared. The survey used a previously validated questionnaire tailored to Italian dietary habits.
On average, people with Parkinson’s were interviewed about five years after the onset of motor symptoms. For comparison, the healthy control group reported their diets from the same time period as their matched Parkinson’s counterparts.
Data on nondietary risk factors, including family history, lifestyle habits, and exposure to environmental toxins, were gathered to compare their relative impact with that of diet.
Using statistical analyses, the team identified seven main dietary patterns based on how different foods tended to be eaten together. Of these, four patterns were significantly linked to Parkinson’s disease risk.
Strongest links seen for those eating processed meats, sweets
The strongest association was seen for processed meats, with people who ate them regularly being about 32% more likely to have Parkinson’s. This was followed by different types of sweets and red meat, which were linked to approximately 20% and 15% higher risks, respectively.
In contrast, those who ate more fruit — particularly citrus fruits — had about a 16% lower risk of developing the disease, the data showed.
“The protective effect of fruits in this study was primarily due to the inverse association with citrus fruits, which may offer neuroprotective benefits through bioactive compounds such as flavonoids, vitamin C, and terpenes,” the researchers wrote.
The researchers noted that these molecules have antioxidant and anti-inflammatory properties that may help reduce oxidative stress and inflammation in the brain, processes believed to contribute to Parkinson’s.
High consumption of sweets … red meat … and processed meats … was associated with an increased [Parkinson’s disese] risk.
By contrast, the team noted that high content of saturated fats, iron, and nitrites found in red and processed meats can promote oxidative damage, inflammation, and neurodegeneration.
Overall, the team noted that “high consumption of sweets … red meat … and processed meats … was associated with an increased [Parkinson’s disese] risk.”
These associations held true even after accounting for other potential influences, such as age, sex, BMI, education level, and known nondietary Parkinson’s risk factors.
Factors like environmental exposure showed stronger link to risk
Importantly, according to the researchers, certain nondietary factors were shown to have a stronger overall link to Parkinson’s risk than a person’s eating habits.
A family history of Parkinson’s, digestive problems, and exposure to pesticides, petroleum oils, metals, or general anesthesia were all tied to a higher likelihood of the disease than frequent consumption of processed meats, sweets, or red meats.
In contrast, coffee drinking and smoking were protective, showing effects comparable in strength to those of fruit consumption, the researchers noted. The team did note that “it is possible that [some of these findings are reflective of] the specific dietary habit of the Italian [Parkinson’s disease] population.”
Still, the researchers concluded that “these findings provide valuable insights for designing future risk factor studies and prevention programs in [Parkinson’s].”
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