Last month a survey in Canada reported that 40 percent of boys between grades 4 and 11 have looked for porn online, and that many of them admit to doing so frequently.

OK, if you are anything like me, and by that I mean a human who grew up with access to the Internet, you know that this is not groundbreaking news. What might surprise you -- but probably shouldn't -- is that in the same survey almost one in five students in grade 11 said they had sent a "sext." Never have playing the game "If You Show Me Yours, I'll Show You Mine" and watching porn been so easy.

The prevalence of teens perusing porn sites should raise concerns for two reasons: recent research regarding porn and the brain, and a growing number of sexual-health experts and young men claiming that Internet porn is causing sexual dysfunctions.

Concern No. 1: Porn's Potential Effects on the Brain

The day before the Canadian survey appeared, a study came out in JAMA Psychiatry. Researchers had scanned the brains of porn users and found:

There was a correlation between time spent viewing porn and reduced grey matter in their brains' reward circuitry (which governs motivation and appetites).

The reward circuitry, which lights up in response to sexual stimuli, showed less activation the more porn individuals had watched (both per week and over the years) even if they weren't addicted.

The connection between the prefrontal cortex, the "executive control" part of the brain, and the reward circuitry was weaker the more porn the users watched -- a risk for impaired decision making.

These three findings normally show up in addicts. Reduced grey matter is associated with needing greater stimulation to achieve the same effect, which was confirmed in finding no. 2. Finding no. 3 is associated with decreased ability to control impulses.

A soon-to-be-published Cambridge University study conducted last year found that brains of compulsive porn users react to cues much like alcoholics and drug addicts. In short, porn users could have a problem on their hands, or, more specifically, in their brains.

And if all that isn't enough to raise concerns, there have been over 60 recent brain-scan studies on Internet and video-game addicts showing some of the same worrying brain changes seen in substance addicts. In a couple of those studies, researchers tracked what happened after the addicts quit and found evidence that the changes had begun to reverse themselves. This is evidence that Internet overuse was indeed the cause of the problems.

If surfing the Internet can have a negative impact on brains, surely it isn't a stretch to think that clicking from porno to porno on the Internet can do the same thing.

All this brain research might help explain a new problem increasingly being reported by sexual-health experts and young porn users. You might find this hard to believe, but many young porn users are finding erections difficult to achieve -- with a real partner or without porn.

Concern No. 2: Developing Porn-Induced Erectile Dysfunction

Recently, a popular news show in Canada covered a new men's sexual-health issue: "porn-induced erectile dysfunction." Dr. Abraham Morganthaler, the director of Men's Health Boston and an associate clinical professor of urology at Harvard Medical School, was featured on the show. He stated:

Now we have it where everybody's got a computer or even a smartphone and you're on the Internet; you can see whatever you want. There's no surprises. ... I think that the concern is what porn has figured out is what really works for the brain of the guys. It's the maximum stimulus.

When asked how prevalent porn-induced ED is, Dr. Morganthaler replied:

It's hard to know exactly how many young men are suffering from porn-induced ED, but it's clear that this is a new phenomenon, and it's not rare.

Other experts have also stepped up to the plate to address why these young men's penises can't stand up for their mates. Eminent urologist Dr. Harry Fisch, author of The New Naked, writes in his book (emphasis mine):

When I say that porn is killing America's sexual behavior, I am not kidding, nor am I exaggerating.

Porn addiction ... is far more common than most people think.

I can tell how much porn a man watches as soon as he starts talking candidly about any sexual dysfunction he has.

A man who masturbates frequently can soon develop erection problems when he's with his partner. Add porn to the mix, and he can become unable to have sex.

In light of the increasing percentage of teens daily consuming pornographic material, research and warnings from sexual-health experts are vital. Unfortunately, Internet porn blew up faster than we could figure out how it affects us.

On the other hand, I figured out how porn affected me a few years ago, when I realized that the only thing that could give me an erection was porn. If you want to hear more about my story, watch the Canadian news show discussed above.