Background and objectives: Although flavonoids have the potential to exert neuroprotective benefits, evidence of their role in improving survival rates among individuals with Parkinson disease (PD) remains lacking. We aimed to prospectively study the association between pre- and post-diagnosis flavonoid intakes and risk of mortality among individuals with PD identified from two large ongoing cohorts of US men and women.
Methods: Included in the current analysis were 599 women from the Nurses’ Health Study and 652 men from the Health Professionals Follow-up Study who were newly diagnosed with PD during follow-up. Dietary intakes of total flavonoid and its subclasses together with major flavonoid-rich foods (tea, apples, berries, orange and orange juice, and red wine) were repeatedly assessed based on a validated food frequency questionnaire every 4 years. Mortality was ascertained via the National Death Index and state vital statistics records.
Results: We documented 944 deaths during 32-34 years of follow-up. A higher total flavonoid intake before PD diagnosis was associated with a lower future risk for all-cause mortality in men (hazard ratio [HR] comparing two extreme quartiles=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), after adjusting for age, smoking status, total energy intake, and other covariates. The pooled HR comparing the extreme quartiles was 0.70 (95% CI: 0.40, 1.22; p-trend=0.25) with significant heterogeneity (p=0.01).
For flavonoid subclasses, the highest quartile of anthocyanins, flavones, and flavan-3-ols intakes before diagnosis had a lower mortality risk compared to the lowest quartile (pooled HR=0.66, 0.78, and 0.69, respectively, p<0.05 for all); for berries and red wine, participants consuming >=3 servings/week had a lower risk (pooled HR=0.77 (95%CI: 0.58, 1.02) and 0.68 (95%CI: 0.51, 0.91), respectively), compared to <1 serving/month. 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 (p<0.05 for all).
Discussion: Among individuals with PD, higher consumption of flavonoids, especially anthocyanins and flavan-3-ols, and flavonoid-rich food such as berries and red wine, was likely to be associated with a lower risk of mortality.