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A new study finds that a flavonoid-rich diet reduces mortality in people with Parkinson’s disease. Robert Lang/Stocksy
  • People living with Parkinson’s disease have higher mortality risk compared to the general population.
  • Researchers recently showed that a diet rich in flavonoids — compounds present in brightly colored foods such as blueberries, strawberries, red wine, and tea — reduces mortality in people with Parkinson’s disease.
  • In the new study, after a diagnosis of Parkinson’s disease, affected individuals lived longer when they added flavonoid-rich foods into their diet.

In the Journal Neurology, researchers from Penn State University, Harvard, and Queens’ University in Belfast, Northern Ireland, leveraged data from two long-range studies — the Nurses Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) — to analyze the effects of diet on longevity in individuals with Parkinson’s disease (PD).

Specifically, researchers chose to examine the effect of flavonoids on mortality in PD patients. Flavonoids are plant-derived molecules found naturally in fruits, vegetables, and common beverages such as tea and red wine.

The metabolites of flavonoids can cross the blood-brain barrier and have been demonstrated to reduce oxidative stress, inflammation, and the hardening of the arteries, known as atherosclerosis.

These special molecular functions give flavonoids neuroprotective properties. In the central nervous system, flavonoid metabolites bind to receptors in the brain that control sedation, anxiety, and can even treat seizure risk. They also can bind monoamine oxidase receptor B, an important pharmaceutical target for reducing the symptoms of PD. For this reason, flavonoids have been of great interest to clinician-researchers treating neurodegenerative diseases such as PD or Alzheimers’ disease.

The current study is informed by the researchers’ prior work in 2012, which found that the risk of developingParkinson’s disease in men was reduced by 40% when they consumed diets high in flavonoids.

Medical News Today asked study author Dr. Xiang Gao, MD, Ph.D., professor of Nutrition Sciences at Penn State University, if there was a lower incidence of PD in countries where diets are high in flavonoids, such as in Mediterranean climates. He replied:

“There is no such clear pattern. However, in our previous study, we observed that dietary patterns with a high intake of fruit, vegetables, legumes, whole grains, nuts, fish, and poultry and a low intake of saturated fat, and a moderate intake of alcohol may protect against PD.”

Dr. Gao and his colleagues report that people living with PD have higher mortality rates than individuals with diabetes, colorectal cancer, ischemic heart disease, or chronic obstructive pulmonary disease.

MNT asked Dr. Natalie Diaz, a board-certified neurologist at the Pacific Movements Disorder Center at Providence Saint John’s Health Center in Santa Monica, CA, about this higher mortality risk in PD patients. She explained:

“There are some studies that show maybe slightly higher risk and other studies have gone all the way to say that they have twice or double the risk, as opposed to people with other chronic diseases […] We also see a great reduction in some of these other chronic diseases over the years.”

“So, cancer risk, stroke risk, all are going down significantly, whereas maybe, the risk of Parkinson’s is going up. We are seeing more and more Parkinson’s disease in the general population […] and less and less of these chronic disorders.”

Studying 1,251 individuals from the NHS and HPFS studies, Dr. Gao and his colleagues measured the proportions of intake from foods such as apples, blueberries, strawberries, tea, oranges, and red wines.

They were able to measure the dietary intake of these individuals for 32–34 years until their death or the end of the study. To reduce the bias that living with PD might cause, due to changes in dietary intake as a sequela of the disease, the scientists quantified foods high in flavonoids before and after the participants’ diagnosis of PD.

Dr. Gao and his colleagues discovered two important results:

  • Participants with PD who ate diets high in flavonoids prior to their diagnosis had lower mortality from all causes.
  • Participants who began high-flavonoid diets after PD diagnosis demonstrated lower mortality rates.

For MNT, Dr. Gao explained:

“Flavonoids are naturally occurring, plant-based dietary components, rich in fruit and vegetables. They give various colors to these plants. Adapting a healthy dietary pattern, high in colorful fruit/veggies (eg., berry fruits), ever after Parkinson’s diagnosis, could slow disease progression and improve survival rate.”

MNT asked Dr. Diaz if she made dietary recommendations to people living with PD. She replied:

“Yes, I do. There has never been sort of a specified regiment of what’s the proper diet in Parkinson’s’ disease. I think there has been accumulating evidence over the last 10 years […] One of the most interesting things coming out of Parkinson’s research, from a lifestyle modification standpoint, is that we are learning that even after your diagnosis of Parkinson’s disease, changes in lifestyle can [slow] the progression of Parkinson’s disease, like mortality risk.

“So, there has been accumulating evidence [about] different diets, exercise, sleep and stress reduction.”

MNT asked Dr. Gao what, in his opinion, is the most important development or new learning in the management of Parkinson’s’ disease.

Dr. Gao replied: “Adopting a healthy lifestyle, such as physical activity and [a] healthy dietary pattern with high intakes of colorful fruit and vegetables. A large number of studies also support the potential neuroprotective effects of coffee and tea.”

Regarding advising individuals living with PD, Dr. Diaz told MNT:

“Patients want to be able to feel that they have some ownership to change the trajectory of their disease — not just rely on medication. So, I go over the literature with them. These are all associations — we haven’t been able to see causality, per se, but […] lifestyle changes could potentially [p]oint to changes in how their disease course goes and complications over the years.”

Dr. Gao’s results, with his collaborators, affirm proactive dietary interventions improve outcomes in people living with PD.