Ask the Doctors

Dear Doctor: I have heard recently from a friend that watching internet pornography can lead to erectile dysfunction. Is this true?

Dear Reader: Your friend may not be far from the truth. To put it simply, the rates of erectile dysfunction have significantly increased over the last 15 years. This has especially been noted in men younger than 40. In 2002, a review of 23 studies from Europe, the United States, Asia and Australia found that the rate of erectile dysfunction in that age group was 2 percent. But in 2011, a study of Europeans found that the rate of erectile dysfunction in men ages 18 to 40 ranged from 14-28 percent. Further, a 2014 study of 367 military personnel ages 21 to 40 found erectile dysfunction in 33.2 percent of the men. Even when excluding military personnel with post-traumatic stress disorder, the rate of erectile dysfunction was 15.7 percent.

Older men can have many physiologic causes for erectile dysfunction, but these are much rarer in younger men. Among such causes are vascular disease from years of smoking, high blood pressure and diabetes. Further, while rates of obesity and diabetes have increased among those under 40, the rate of cigarette smoking has decreased. So, if the risk factors for ED have not increased substantially, why the dramatic risk in ED? Some have said that the increase in erectile dysfunction has coincided with easy access to internet pornography.

In fact, many studies have found a correlation between an increase in pornography use and a decline in sexual desire, sexual arousal, enjoyment of sexual intimacy and sexual satisfaction as well as more sexual problems, such as erectile dysfunction. Addiction to pornography seems to affect the brain reward pathways, leading to a reward mechanism that can only be fulfilled with cues found in pornography and dulling the brain's responsiveness to normal sexual stimuli. In a way, increasing pornography desensitizes the individual to sexual stimuli.

However, two studies contradict the idea that internet pornography leads to greater erectile dysfunction. The first -- a study of 280 men -- found a correlation between a weekly increase in the watching of sexual stimuli and a mild increase in the desire for sex. The second -- an online European study of 2,737 men under the age of 40 -- found no link between the use of pornography and sexual dysfunction, though it did find higher rates of low sexual desire than had been reported in past studies of this age group.

Ultimately, pornography may not be the underlying issue. For one, more men may be using pornography because of a greater feeling of isolation and a greater inability to be sexually intimate. Second, a society that spends much of its time on computers, both in work and personal time, fosters a decrease in -- and alteration of -- human contact, which may lead to anxiety with sexual intimacy.

The fact remains that the rates of erectile dysfunction are increasing in men younger than 40, and while pornography may be part of the equation, it may actually be a symptom and not a cause. The bigger issue may be greater social isolation and difficulties with intimacy.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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