Happy, Healthy, and Hard

Experts explain the connection between a man's overall health and his sexual health.

Medically Reviewed by Louise Chang, MD on February 02, 2010
6 min read

As the saying goes, the best measure of a man's character is the company he keeps. But what about his health? According to Steven Lamm, MD, the best measure of that is his erect penis.

In his book, The Hardness Factor, Lamm argues that a man's overall health directly affects the quality of his erections. And if the promise of longer life isn't enough to convince men to take care of themselves, the promise of harder erections might be.

"It's still the greatest hook to get men to make some real changes," says Lamm, who practices internal medicine in New York City.

Since The Hardness Factor came out in 2005, it has become hard to deny the importance of erections in men's health.

By the early 2000s, it was clear that men with heart disease were more likely to develop erectile dysfunction (ED). But recent studies have shown that the association goes the other way, too. In seemingly healthy men, ED may be an early sign of heart disease.

Here's a quick look at three studies showing a link between heart disease and ED.

The most recent of those studies, published in the journal Mayo Clinic Proceedings in 2009, showed that ED may predict future heart disease. The 1,400 men who took part in that study had never been diagnosed with heart disease. But over the next decade, men with ED were 80% more likely to develop heart disease than men without ED -- regardless of smoking, high blood pressure, diabetes, and weight.

Men in their 40s who had ED had the most dramatic increase in heart disease risk. They were more than twice as likely to develop heart disease as men of the same age without ED.

Another study, published in The Journal of the American Medical Association in December 2005, tracked heart disease risk and ED in more than 9,000 men age 55 and older. The key finding: After accounting for other risk factors, men with ED were 45% more likely to develop heart disease over a five-year period. That's about the same increase in risk that has been linked to smoking or high cholesterol, the researchers noted.

The third study, published in the journal European Urology in September 2005, showed that men with moderate-to-severe ED were 65% more likely to develop heart disease over a 10-year period compared with men who didn't have ED. That study included about 2,500 Austrian men age 30-69.

There is little doubt about the common cause of ED and heart disease. It's atherosclerosis, also known as hardening of the arteries.

In atherosclerosis, fatty deposits build up inside arteries and form a plaque, making the walls of the arteries stiff and restricting blood flow. Eventually, chunks of plaque may break off into the bloodstream and lodge somewhere else, where they block blood flow. If a blockage forms in the heart, it causes a heart attack; in the brain, it causes a stroke.

Scientists think that the disease starts with damage to the endothelium, a layer of cells lining the arteries.

What does that have to with an erection?

To get erect, the penis must become engorged with blood; and for that to happen, the endothelium must relax, allowing the arteries to widen and let blood flow into the penis.

"Arteries that lead to the penis are smaller than the arteries that lead to the brain or the heart," says Ira Sharlip, MD, a urologist at the University of California, San Francisco.

Hardening of the arteries begins to affect those small arteries long before any change is noticeable in the larger arteries.

Sharlip has been studying ED for more than a decade. In 1996, two years before Viagra was approved, he was one of the doctors who wrote the American Urological Association's guidelines on treating ED. At the time, ED was the domain of specialists in sexual medicine, particularly urologists.

That is changing. "If a man of 45 or 50 with no other problems develops ED, he should go to a primary care physician," Sharlip says.

Doctors assume that if ED is diagnosed early, some men could head off heart disease by making lifestyle changes, such as quitting smoking, eating a healthier diet, and exercising.

But right now, that's just an assumption; there isn't evidence yet showing that men who have ED but not heart disease could take measures to prevent it.

Lamm says he is interested in finding out what ideal erectile function is.

"Why do we need to wait until a man has erectile dysfunction before we intervene?" he says.

By definition, having ED means a man cannot get an erection hard enough for penetration or one that lasts long enough for him to reach orgasm. But in Lamm's opinion, wellness isn't "the absence of illness." There are shades of gray between excellent sexual function and dysfunction.

The American Heart Association has defined an optimal cholesterol level. There should be a similar measure for erectile function, Lamm says. "I think we need to do this in all areas so that people have some sort of benchmark."

Researchers usually assess erectile function by the International Index of Erectile Function, a set of five questions such as, "How do you rate your confidence that you could get and keep an erection?" A patient's answers are scored, and that score determines whether or not he has ED.

In 2005, when he wrote his book, Lamm was using a tool called a rigidometer to measure erectile function. A man presses the head of his erect penis against a sensor attached to the digital device, which measures the precise hardness of his penis in grams of pressure.

Lamm says he's now studying ED using an even newer device that measures the function of the endothelium, instead of the hardness of an erect penis.

"When we wrote the book, we had no way of looking at endothelial function," Lamm says.

This new technology uses a blood pressure cuff and two sensors placed on a man's index finger. The sensors, hooked up to a computer, measure blood flow returning to the fingers after the inflated cuff squeezes off the blood supply for about five minutes. Based on data from the sensors, the computer generates a score of endothelial function.

Lamm says he has been able to perform about 1,000 of these tests a year on patients, and he's hoping that the data will help him find an optimal range related to hardness and heart disease risk.

Lamm says he thinks men want harder erections, even if they're not worried about ED or heart disease.

A rigidometer could show a man objectively how hard his penis is -- hard enough for penetration, maybe, but not as hard as it could be. An endothelial function test could tell him about how close or far away he is from heart disease. Either number could be an incentive for him to improve his sexual or cardiovascular health.

Sharlip says he's not sure if the idea of preserving or enhancing erectile function could motivate men to make healthier lifestyle choices. "I don't know of any studies that show whether it's a factor," he says.

Based on his professional experience, Sharlip says, "I think it matters to some men." But he also says he thinks that many young men feel invincible, and wouldn't be swayed to change their habits.

Lamm says he has not studied whether information about erectile function really motivates men to change. But he says he sees anecdotal evidence in his day-to-day practice as a doctor.

Men may care about hardness, but they don't know where they stand in relation to what's normal or ideal, he says.

That's because men typically don't talk about the quality of their erections with other men. "You don't want to hear another guy telling you how hard it is," Lamm says. But he adds, "They like to talk to me about it. They come with their wives. It happens every day."