Men: If you like to eat blueberries, you may beat the odds on developing erectile dysfunction (ED). It also helps if you eat strawberries, oranges, grapefruit, apples and pears—and drink red wine.

So suggests a new study. But we still had questions. ED can be caused by some serious health issues. Could a handful of berries really be that powerful?

To find out, we checked with nutrition expert and board-certified internist John La Puma, MD. He reviewed the scientific literature on diet and men’s sexual health and conducted original clinical research in preparation for his latest book, Refuel: A 24-Day Eating Plan to Shed Fat, Boost Testosterone, and Pump Up Strength and Stamina.

Turns out, he’s pretty positive about blueberries and other ways that diet and lifestyle changes can prevent—even reverse—ED.

THE FLAVONOID BOOST

In the study, Harvard researchers analyzed the diets and ED symptoms of 25,000 men in the Health Professionals Follow-Up Study. In the period that this analysis focused on, the men were in their 50s, 60s and 70s and older. The researchers focused on phytochemicals called flavonoids—and the foods, mostly fruits, that are the biggest source of them in the American diet.

Results: Men whose diets were higher in these flavonoid-rich fruits were 14% less likely to develop ED over a 10-year period. Citrus fruits were a major flavonoid contributor. (Dark chocolate and soy foods, both of which are also flavonoid-rich, were not studied in this analysis.)

Blueberries stood out. In a separate analysis, men who ate them more than three times a week, on average, were 22% less likely to develop ED.

What’s so special about flavonoids? “Berries here are acting in the same way as Viagra,” explains Dr. La Puma, “but they’re a lot cheaper and they taste better.” In animal studies, flavonoids inhibit a biological pathway that makes the penis flaccid…and boost production of nitric oxide, which facilitates erections during sexual activity. In one study of rats with diabetes and ED, for example, adding a specific flavonoid (quercetin) to their chow actually reversed ED.

Medications such as sildenafil (Viagra) work through similar mechanisms, but unlike blueberries, they don’t promote heart health—and they have side effects.

To be sure, no one is saying that you can pop a few blueberries in your mouth, wait a half-hour and jump into the sack. The study unveiled not a quick fix but a long-term benefit of a flavonoid-rich diet. The good news: While you’re saving your sexual function, you’re likely saving your heart, too.

BEYOND PREVENTION

The diet connection makes sense when you realize that erectile dysfunction often is a cardiovascular problem, said Dr. La Puma. “The penile artery is about half the width of the coronary artery, so inflammation there creates symptoms first. Men with ED have cardiac disease until proven otherwise—it’s an early warning sign.”

That’s why a heart-healthy diet is so important for prevention—and even treatment—of ED. In one study, he notes, men with ED who ate three ounces of heart-healthy flavonoid-rich pistachios for three weeks had improvement in their symptoms. Another study found that flavonoid-rich walnuts, like blueberries, boost nitric oxide production. Says Dr. La Puma, “A number of studies have shown that the dietary pattern, especially a Mediterranean diet…along with other interventions such as quitting smoking and increased physical activity…can be both preventive and therapeutic.”

ANOTHER NOTCH IN THE BLUEBERRY BELT

On the other hand, if you’re looking for just one food to add to your diet to improve your health, and perhaps help preserve your sexual vitality, you can’t go wrong with blueberries.

It’s not just men who benefit. Blueberries are good for brain health in both men and women, improving cognitive function and memory in older adults.

And if any women are reading this article, there’s a heart benefit for you, too. The same Harvard group that discovered the ED connection reported a few years ago that women who consumed at least three servings of blueberries or strawberries a week were 34% less likely to get heart disease.

Blueberries—quite a sexy food indeed.