SUNDAY, Dec. 30 (HealthDay News) -- If heart disease, stroke and certain cancers haven't been reason enough for men to quit smoking, consider this: The habit also increases the risk of erectile dysfunction.

In fact, emerging research shows that men with a pack-a-day habit are almost 40 percent more likely to struggle with erectile dysfunction than men who don't smoke.

"Smoking delivers nicotine and other vasoconstrictors that close down the blood vessels" of the penis, explained Dr. Jack Mydlo, chairman of urology at Temple University School of Medicine and Hospital in Philadelphia.

Erectile dysfunction -- also called "ED" or impotence -- is the inability to achieve or sustain an erection on repeated occasions. It's estimated that about two of every 100 American men have erectile dysfunction serious enough to warrant a doctor's visit, according to the U.S. National Institute of Diabetes and Digestive and Kidney Disorders. As men age, the risk of erectile dysfunction increases.

A recent study of more than 8,000 Australian men between the ages of 16 and 59 found that those who smoked less than a pack a day had a 24 percent increased risk of erectile problems. And, as the number of cigarettes smoked went up, so, too, did the chances of erectile dysfunction. Those men who averaged more than 20 cigarettes a day increased their risk of erectile dysfunction by 39 percent, reported the study, published in the journal Tobacco Control.

Another study, this one published in the American Journal of Epidemiology, found that male smokers in their 40s were more likely to experience erectile difficulties than older nonsmoking males. The risk of erectile dysfunction was nearly doubled for smoking men in their 40s compared to nonsmokers in their 50s.

"Smoking, because it causes blood vessel constriction, is a very big cause of erectile dysfunction," said Dr. Larry Lipshultz, chief of male reproductive medicine at Baylor College of Medicine in Houston.

Smoking isn't the only cause of impotence problems -- other lifestyle habits can have a big impact on men's sexual health. Obesity, heavy alcohol consumption and recreational drug use can all cause erectile dysfunction. And a sedentary lifestyle can also contribute to erectile problems, Lipshultz added.

Other causes include diabetes; heart disease; cancer surgery of the prostate, bladder, colon or rectum; high blood pressure medications or antidepressants; a spinal injury; and a hormone imbalance, usually low testosterone, Lipshultz explained.

All of these conditions or lifestyle factors contribute to erectile difficulties in three major ways: By reducing blood flow, causing nerve damage, or changing the hormonal environment.

While there are medications that can help treat erectile dysfunction, both Mydlo and Lipshultz advocated a healthy lifestyle for maintaining good sexual health.

"Take better care of yourself. Make sure you're not obese, eat well, exercise, and if you have diabetes or hypertension, make sure they're well-controlled," advised Lipshultz, who added that by addressing lifestyle factors, you may not need medication to treat erectile dysfunction.

Mydlo echoed that advice, adding, "Stop smoking, drink in moderation, lose weight, and maintain good blood pressure."

Mydlo added one more word of caution: "Don't use ED medications -- Viagra, Cialis -- if you don't need them. Erections that last longer than four hours -- priapism -- can cause permanent scar tissue and permanent impotence. It's not a good idea to use these drugs casually."

More information

To learn more about erectile dysfunction and how to prevent it, visit the National Institute of Diabetes and Digestive and Kidney Diseases.

SOURCES: Larry Lipshultz, M.D., chief, male reproductive medicine, and professor, urology, Baylor College of Medicine, Houston; Jack Mydlo, M.D., professor and chairman, urology, Temple University School of Medicine and Hospital, Philadelphia; March 2006 Tobacco Control; American Journal of Epidemiology

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