For men affected by erectile dysfunction, help may be a workout away.

A major new study of American males suggests regular exercise and a healthy diet may help banish ED and the heart disease that often accompanies it.

"Lifestyle intervention, such as exercise and diet, may be effective treatment for ED," said study author Elizabeth Selvin, a research fellow at Johns Hopkins Bloomberg School of Public Health in Baltimore.

Her team presented the study at the American Heart Association annual conference on Cardiovascular Disease Epidemiology and Prevention, in Phoenix.

"This is the first study with national data on the prevalence of ED in the United States," Selvin said.

"ED varies by age, with 5 percent of men aged 20 to 40 having ED, to 70 percent of men 70 and older," she noted. In fact, the study suggests that about 18 million American men are affected by erectile difficulties.

ED is especially prevalent among men with high blood pressure, diabetes and other cardiovascular risk factors, Selvin said.

Her team collected data on ED from more than 2,200 adult men, all participants in the U.S. federal government's 2001-2002 National Health and Nutrition Examination Survey (NHANES).

"The results suggest that in men with ED, screening for cardiac risk factors such as diabetes and hypertension may be warranted," Selvin said. "The converse [is also true], that screening for ED in men with hypertension or diabetes should be considered," she added. In fact, she said, "we found ED in 50 percent of men with type 2 diabetes."

Selvin noted that "couch potato" men were much more likely to develop erectile difficulties, suggesting that getting off the couch and getting active might help fight the problem.

"The association of ED with cardiovascular risk factors may be a powerful motivator for men for whom diet and lifestyle changes are indicated," Selvin said.

One expert sees a direct connection between ED and risk factors for heart disease.

"Diabetes and hypertension are common in the general population, so it should come as no surprise that they are also common in a population of patients who suffer from ED," said Dr. Arthur Schwartzbard, director of Clinical Lipid Research at New York University's Lipid Treatment and Research Center.

In fact, estimates from surveys very similar to NHANES have suggested that a constellation of risk factors, called the "metabolic syndrome," is present in almost half of middle-aged adults in the United States, he said. Metabolic syndrome is characterized by insulin resistance, obesity, high blood pressure, glucose intolerance, low HDL cholesterol, high triglycerides, and high blood levels of small, dense LDL cholesterol particles.

"Screening for risk factors such as hypertension and diabetes should be done in all patients, not just those with ED," said Schwartzbard, who is also director of noninvasive cardiology and an assistant professor of medicine at NYU School of Medicine. "Lifestyle modifications such as exercise and weight loss for patients with the metabolic syndrome have been shown to prevent almost two-thirds of new-onset diabetes cases," he added.

Increasing physical activity, weight loss, and control of high blood pressure, cholesterol and diabetes can also reduce the incidence of heart attacks and strokes, Schwartzbard said, so "I would expect that such overall lifestyle changes could have a positive impact on the incidence of ED in the U.S."