Flavonoid-rich Diets Appear to Aid Survival With Parkinson’s
People with Parkinson’s disease who regularly eat foods rich in flavonoids — plant-produced metabolites abundant in colorful fruits and plants, from berries and teas to dark chocolate and red wine — have a lower mortality risk than patients who rarely eat these foods, a study that followed people for up to 34 years suggests.
This lower risk was observed both before and after a Parkinson’s diagnosis.
“Adding a few servings of flavonoid-rich foods to their diets a week could potentially be an easy way for people with PD [Parkinson’s disease] to help improve their life expectancy,” Xinyuan Zhang, PhD, the study’s first author and a doctoral candidate in nutritional sciences at Penn State University, said in a press release.
“Greater consumption of berries and red wine, which are rich in the flavonoid anthocyanins, was particularly associated with lower mortality,” Zhang added.
The study, “Intake of Flavonoids and Flavonoid-Rich Foods, and Mortality Risk Among Individuals With Parkinson Disease: A Prospective Cohort Study,” was published in the journal Neurology.
Previous studies also suggest that flavonoid consumption could have neuroprotective properties for Parkinson’s patients.
A regular diet rich in colorful fruits and vegetables, as well as plants like teas and cocoa, is also thought to possibly lower a person’s risk of developing Parkinson’s. But studies are lacking into their possible longevity benefits for those with the disease.
“Our group’s previous research found that when people without Parkinson’s ate more flavonoids, it was associated with a lower risk of them developing the disease in the future,” said Xiang Gao, MD, a professor of nutritional sciences at Penn State and the study’s lead author. “We wanted to further explore whether flavonoid intake could be linked to better survival in individuals who had already been diagnosed with Parkinson’s.”
The researchers assessed flavonoid consumption among 599 women and 652 men newly diagnosed with Parkinson’s in the United States. Women were diagnosed while participating in the Nurses’ Health Study and men while in the Health Professionals Follow-up Study, two ongoing and long-term studies into how lifestyle habits, including nutrition, impact the risk of illnesses and death.
The study’s 1,251 participants completed a validated food frequency questionnaire every four years, which included questions regarding how often they ate flavonoid-rich foods, such as tea, green leafy vegetables, nuts, apples and peaches, berries, oranges and orange juice, and red wine.
To calculate the flavonoid intake, researchers multiplied the flavonoid-food content by the numbers of times flavonoid-rich foods were consumed.
All were followed a mean of 32 to 34 years, during which a total of 944 deaths were registered.
People who consumed the most flavonoids — highest 25% group — were found to have had a 70% greater chance of survival compared to those with the lowest intake, after controlling for factors, like age and smoking status, and dietary habits. These people consumed about 673 milligrams (mg) each day, while the lowest group ate about 134 mg of flavonoids each day.
A higher total flavonoid consumption before a Parkinson’s diagnosis was also seen to associate with a lower risk for death due to any cause in men, but not in women.
Researchers then analyzed the effects of individual flavonoids, namely anthocyanins (found in red wine and berries), flavones (found in herbs and vegetables like parsley, artichokes, and green beans), and flavan-3-ols (found in apples, tea and wine).
People who were the top 25% consumers of anthocyanins had a 66% greater survival rate relative to those in the lowest 25%, while the top 25% consumers of flavan-3-ols had a 69% greater survival rate compared with the lowest 25%.
People who consumed three or more servings of berries and red wine each week also had a lower mortality risk relative to those who consumed one or fewer servings per month. The researchers noted that U.S. dietary guidelines for wine recommend one glass a day for women and two for men.
Notably, a diet high in various types of flavonoids among diagnosed patients was also associated with a lesser likelihood of dying.
“After PD diagnosis, greater consumptions of total flavonoid, subclasses including flavonols, anthocyanins, flavan-3-ols, and polymers, and berries and red wine, were associated with lower mortality risk,” the researchers wrote.
The benefits of flavonoids may be due to their acting as antioxidants, substances that protect cells against damaging free radicals, which may work to lower inflammation, the researchers suggested.
“Flavonoids are antioxidants, so it’s possible they could be lowering chronic neuroinflammation levels,” Zhang said. “It’s also possible they may interact with enzyme activities and slow neuron loss and could protect against cognitive decline and depression, which are both associated with higher mortality risk.”