The population study published in the American Journal of Clinical Nutrition found three portions of citrus fruits and berries were associated with a 19% reduction in risk of erectile dysfunction or 21% if coupled with exercise.
Erectile dysfunction is a significant global health problem affecting 33-52% of middle aged men, according to the authors.
Previous research has shown the predominant cause of erectile dysfunction to be vascular, with the issue sharing risk factors with cardiovascular disease (CVD), hypertension and obesity.
Flavonoids have been shown to be beneficial for diabetes and CVD risk, but this study is the first to examine the associations between flavonoids and erectile dysfunction. Growing evidence supports an improvement in endothelial function and blood pressure after dietary flavonoid intake, which suggests that erectile dysfunction may also be improved.
Scientists examined the six main subclasses of flavonoids commonly consumed in the US diet and their effect on erectile dysfunction.
They conducted a prospective study among 25,096 men from the Health Professionals Follow-Up Study, calculating flavonoid intakes from a food frequency questionnaire collected every four years from 1986 onwards. Participants also rated their historical erectile function at four year intervals.
Those with prostate, bladder or testicular cancer or CVD were excluded. Participants were followed up between 2000 and 2010 during which time 35.6% reported erectile dysfunction.
After adjusting for potential confounders including CVD and lifestyle risk factors, men in the highest compared with the lowest quintile of intakes of flavanones, flavones, and anthocyanins had a 9–11% reduced incidence of erectile dysfunction. The strongest associations were among men of age 70 years.
The authors said this magnitude of effect equates to around two to five hours of brisk walking per week.
The researchers also conducted food based analyses for total fruit intake and the top five sources of anthocyanins, flavones, and flavanones: strawberries, blueberries, red wine, apples/pears, and citrus products.
Total fruit intake was associated with a 14% reduction in risk of erectile dysfunction, and intake of citrus and blueberries specifically was associated with a 19% reduction in risk at 3 portions per week.
Exercise and risk reduction
Exercise coupled with flavonoid intake had a greater effect at 21% reduction in risk "pointing towards the fact that if you have a healthy diet together with physical activity and maintenance of body weight you get these additional benefits for sexual health but more importantly may reduce your risk of having a heart attack as well," Professor Aedin Cassidy from the University of east Anglia told us.
She said that erectile dysfunction is an early warning sign that might encourage men to go to their doctors.
Better dietary guidance
"We’ve known for a long time that higher fruits and vegetables are associated with (reduced risk) of cardiovascular disease but equally we know that not all fruits and vegetables are the same and I think the population need more refined guidance on that," said Cassidy
"It may be that some fruits and vegetables are better for some health endpoints than others and for CVD the benefits seem to be the fruit based flavonoids, the citrus fruit ones which are called flavonones and the berry based ones called anthocyanins."
Flavonoid supplements may not act in the same way, however "these studies are on habitual diets and things that people commonly consume, and there’s no evidence at all to date that flavonoid supplements work in the same way," said Cassidy
"If you think that the NHS [UK National Health Service] is trying to shift its agenda towards prevention here’s an example of quite simple changes that you could do to reduce your risk," she told us.
Source: American Journal of Clinical Nutrition
Published online ahead of print, doi:10.3945/ajcn.115.122010.
“Dietary flavonoid intake and incidence of erectile dysfunction”
Authors: A. Cassidy, M. Franz, E.B. Rimm.