A diet higher in flavonoid-rich foods like berries, apples, tea, and red wine was tied to lower mortality risk in people with Parkinson's disease.
Diets with the highest quartile of total flavonoid intake before Parkinson's diagnosis were associated with lower future risk for all-cause mortality in men (HR 0.53, 95% CI 0.39-0.71, P trend<0.001), but not in women (HR 0.93, 95% CI 0.68-1.28, P trend=0.69), compared with the lowest quartile, after adjusting for age, smoking status, total energy intake, and other covariates, reported Xiang Gao, MD, PhD, of Pennsylvania State University in University Park, and co-authors.
After Parkinson's disease diagnosis, higher intakes of total flavonoid and several subclasses including flavonols, anthocyanins, flavan-3-ols, and flavonoid polymers were associated with lower mortality risk (pooled adjusted HR 0.78, 0.66, 0.59, 0.75, and 0.65, respectively, P<0.05 for all), they wrote in .
Anthocyanins (found in berries and red wine) and flavan-3-ols (found in apples, tea, and red wine) were consistently associated with lower risk of death, both before and after Parkinson's diagnosis.
For flavonoid-rich foods, a higher intake of berries and red wine after Parkinson's diagnosis was associated with lower mortality risk (pooled HR comparing three or more servings/week versus less than one serving per month 0.74 and 0.60, respectively, P<0.05 for both).
"This is the first study to examine the risk of mortality among individuals with Parkinson's disease in relation to the habitual diet," Gao and co-authors noted. "Although direct comparison with other studies cannot be made, our results are in line with those from previous studies on related topics, e.g., an association between flavonoids intake and , and flavonoids intake and mortality in general populations."
"Oxidative stress can lead to alpha synuclein aggregation found in Lewy bodies, a hallmark of Parkinson's disease," noted Thomas Holland, MD, of Rush University in Chicago, who wasn't involved with the study. "Further, inflammation from microglial activation in response to an immune reaction can lead to dopaminergic neuronal loss," he told Ƶ.
"Flavonoids, as we know them, have antioxidant and anti-inflammatory properties," Holland said. "Thus, a higher dietary intake of flavonoids through a diet diverse in fruits and vegetables has the potential to be protective and perhaps slow disease progression."
"It's currently understood that most, if not all, neurodegenerative disease processes involve a degree of inflammation and oxidative stress, to some extent," he added. "Given the inherent properties of flavonoids, it's important to ensure our diets are rich in foods that have a diverse quantity and quality of nutrients and bioactives. Additional lifestyle factors like physical activity, cognitive activity, and appropriate sleep quality have the capability to bolster these protective aspects."
The analysis was based on participants in two longstanding, ongoing cohorts -- 599 women from the and 652 men from the -- who were newly diagnosed with Parkinson's disease during follow-up.
The researchers assessed dietary intake of total flavonoid and its subclasses and major flavonoid-rich foods using food frequency questionnaires every 4 years until June 2018. They determined mortality through the National Death Index and state vital statistics records.
Mean ages at Parkinson's diagnosis were 73 for men and 72 for women. In both groups, people who consumed more flavonoids were more likely to never smoke, have higher physical activity levels, and higher intake of vitamin C, vitamin E, and beta-carotene.
Adjusting for vitamin C, vitamin E, and beta-carotene intake did not substantially alter overall findings in both pre- and post-diagnosis analyses, Gao and co-authors said.
People in the highest quartile consumed an average of 673 mg of flavonoids each day; the lowest quartile consumed 134 mg.
During 34 years of follow-up, 944 people (528 men and 416 women) died. Overall, 513 people died from Parkinson's, 112 died from cardiovascular diseases, and 69 died from cancer.
The study had several limitations, the researchers acknowledged. Severity of Parkinson's disease was unknown, which may confound results. Both cohorts included predominantly white healthcare professionals, and findings may not apply to others. In addition, food frequency questionnaires may not have captured flavonoid intake accurately.
Disclosures
This study was supported by the National Institute of Neurological Disorders and Stroke.
Gao and co-authors reported no disclosures relevant to the manuscript.
Holland reported no disclosures.
Primary Source
Neurology
Zhang X, et al "Intake of flavonoids and flavonoid-rich foods, and mortality risk among individuals with Parkinson disease: a prospective cohort study" Neurology 2022; DOI: 10.1212/WNL.0000000000013275.