Clinical Context

Erectile dysfunction (ED) affects an estimated 33% to 52% of middle-aged men worldwide, with significant impact on quality of life. Although psychogenic or neuropathic factors may play some role in some cases, the predominant etiology is vascular.

Evidence to date supports an association of higher dietary intake of several flavonoids found in berries and other fruits with lower risks for diabetes and cardiovascular disease. However, no previous research has addressed associations between dietary flavonoid intake and erectile function. The goal of this study was to evaluate possible associations between diets varying in flavonoid subclasses and ED incidence.

Study Synopsis and Perspective

Eating berries and citrus fruit may reduce the risk of men experiencing problems getting and maintaining an erection, according to a new study^[1,2] by the University of East Anglia (UEA), Norwich, United Kingdom, and Harvard University, Boston, Massachusetts.

What these foods have in common is they are especially high in flavonoids, substances that are found in almost all fruit and vegetables. This diverse group of chemicals is largely responsible for the eye-catching colors in our fruits and vegetables.

Antioxidants

In recent years, scientists have been examining whether the antioxidant and anti-inflammatory properties of flavonoids might help explain the health benefits associated with eating our 5-a-day. Some studies have linked them with helping prevent cancer and improving heart health.

The latest study, published in the American Journal of Clinical Nutrition, examined whether eating foods containing flavonoids could help prevent erectile dysfunction (ED) by improving vascular health. Researchers concentrated on 6 main types of commonly eaten flavonoids and found that 3 in particular -- anthocyanins, flavanones, and flavones -- are beneficial.

"It's all about inadequate blood supply and impaired blood flow," says lead researcher Aedín Cassidy, PhD, from UEA, "and what's really interesting about the flavonoids is that there's clinical trial data and also lab data suggesting that they can improve blood pressure, they can improve blood flow and make our arteries more flexible."

The researchers examined data from 25,096 professional men who enrolled in a US health study in 2000. At the start of the study, the participants rated whether they were able to achieve an erection sufficient for intercourse to happen, and rated their erectile function again in 2004 and 2008. They were also asked to rate their ability to have an erection in past years as far back as 1986.

The men also recorded their eating patterns every 4 years.

During the course of 10 years, 35.6% of men reported having trouble getting an erection for the first time. However, those who consumed a diet rich in anthocyanins, flavones, and flavanones were less likely to experience the condition, the research found.

Berries and Citrus Fruits

Dr Cassidy says that a reduction in risk was associated with eating any fruit, but some fruits were more effective than others. "When we looked at specific fruits, the greatest benefits were from berries, [which contain] flavonoids called anthocyanins that are responsible for that lovely blue-red colour you get in berries and in aubergines."

The next most effective were citrus flavanones, she says.

Major sources of anthocyanins, flavones, and flavanones include strawberries, blueberries, blackberries, grapes, red wine, apples, pears, cherries, and citrus products.

The authors caution that their study was observational, based on data drawn from an established health study, rather than a clinical trial where cause and effect are measured under strict conditions.

Eating More Fruit

However, Dr Cassidy says the good news is that eating more readily available fruit could improve your health. "Just incorporating a few extra portions of fruit, particularly berries and citrus in the diet, will not only benefit your sexual health but in the longer term would offer protection against having a heart attack," she says.

Commenting on the findings in an email, Claire Pettitt, spokesperson for the British Dietetic Association, says: "Foods containing flavonoids, i.e., plant-based foods, especially fruits and vegetables, should make up a large part of our diets as we already know they provide many health benefits such as improving cardiovascular function and heart health, reducing risk of cancer and antioxidant effects, anti-inflammatory properties and improvements in blood flow to the brain which can lead to improved cognitive function.

"The study also showed that the benefits achieved from consuming flavonoids matched the benefit already known to be gained from increased exercise and that in fact, a combination of a healthy diet containing a variety of flavonoids, and regular exercise had a cumulative effect.

"This research really supports the recommendation to have fruits and vegetables everyday as part of a healthy balanced diet and to be regularly physically active."

Clinical Implications

• Higher habitual intake of fruit rich in flavonoids is significantly associated with lower ED incidence, based on a large observational study.
• The greatest associations with reduced ED incidence were with berries, and citrus flavanones were the second most effective.
• Implications for the Healthcare Team: Members of the healthcare team should be aware that regardless of specific benefits associated with reducing the risk for ED, dietary intake of fruits and vegetables rich in flavonoids should be encouraged for their other health benefits.

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