A recent meta-analysis published in The American Journal of Clinical Nutrition concluded that high, habitual flavonoid intakes were significantly associated with a reduced risk of hospitalizations related to peripheral artery disease (PAD).
 
PAD, which involves an obstruction of arteries most commonly manifesting in the lower extremities, rises in prevalence with age, and it is believed that this disease will rise in prevalence as the global population ages. Flavonoids have long been associated with positive cardiovascular outcomes, however, their role in PAD specifically is uncharacterized. Evidence suggests that flavonoids can lower blood pressure, and improve NO availability and endothelial function.
 
“The role that nutrition plays in the primary prevention of PAD is not well understood,” the authors said. “Previous observational studies suggested that a diet characterized by low intakes of vitamins, dietary fiber, and PUFAs, and a high intake of red meat, was associated with a higher incidence of PAD.” Previous observational studies have posited that cardiovascular benefits achieved through the Mediterranean diet are, in large part, due to the high flavonoid content of the foods most prevalent to that pattern of eating. “Flavonoids may impede the initiation and progression of PAD by restoring endothelial homeostasis through the augmentation of NO bioavailability and by attenuating inflammation[…]”  
 
Utilizing data from 55,647 participants of the Danish Diet, Cancer, and Health study who were recruited with no PAD at baseline, from the year 1993-1997, with a median follow-up period duration of 21 years. Flavonoid intake was calculated from food frequency questionnaires which were a part of the study.
 
After the follow-up period, a total of 2,131 participants were hospitalized for PAD. 993 of the hospitalizations were due to atherosclerosis, 800 for aneurysm, 161 for an embolism or thrombosis, and 653 for other PVD. The researchers found that there was a non-linear relationship between flavonoid intakes and PAD hospitalization risk, with the risk reduction plateauing somewhere between 750-1,000 mg of flavonoids consumed per day.
 
Compared to the median flavonoid intake in quintile 1, which was roughly 174 mg of flavonoids consumed daily, an intake of the maximally beneficial 1,000 mg/d dose resulted in a 32% risk of any PAD hospitalization, and a 26% lower risk of atherosclerosis, a 28% lower risk of aneurysm, and a 47% lower risk of hospitalization for other peripheral vascular diseases.
 
A higher total flavonoid intake was also significantly associated with a lower incidence of vascular surgeries, or lower extremity amputations, the researchers said, though all of the aforementioned benefits were affected by smoking status, alcohol intake, BMI, and diabetes status. Interestingly, flavonoid consumption resulted in a lower PAD risk for smokers, who are at especially high risk for this disease, suggesting that flavonoids may counteract the inflammatory effect that smoking has on the vascular system.
 
“Our results emphasize the importance of a flavonoid-rich diet in mitigating PAD risk,” the authors concluded. “Despite the positive findings of the present study, evidence from randomized controlled trials is urgently needed.”