Doctors can't agree on whether patients with cancer, HIV, glaucoma and other conditions get any benefit from smoking marijuana. Last week, two studies published in the British Medical Journal found that marijuana isn't any better for treating pain and nausea than standard drug therapy.
And the U.S. Supreme Court's decision in May to not legalize the manufacture and sale of pot for medical use only deepens the debate.
Meanwhile, scientists continue to study whether people who smoke pot strictly for pleasure are endangering their health. In June, researchers at Boston's Beth Israel Deaconess Medical Center reported that a person's risk of having a heart attack increases fivefold in the first hour after smoking marijuana. A fivefold increase doesn't mean much for a young, healthy person, since the risk of suffering a heart attack is minuscule to begin with. But for older smokers, and anyone with a condition that increases the risk for cardiovascular disease (such as diabetes), the study may offer a reason to think twice before getting high.
Which got me thinking: Are the guys I know who unwind with this illicit herb putting their health at risk in other ways? For the record, the majority of pot smokers in this country are men. According to government figures, adult males are nearly 21/2 times more likely than females to say they have used marijuana in the last month. Among Americans older than 35, male pot smokers outnumber female users by even greater numbers.
So, are these guys doing themselves any harm? Several pieces of pot wisdom about the health of men who smoke marijuana have been handed down over the years. Back in college, I recall hearing that male pot smokers often develop gynecomastia, or saggy breasts. Frequent marijuana use is also rumored to lower a man's sperm count and cause impotence, or erectile dysfunction.
But none of these claims has ever been proved true in humans, says Dr. Paul Gahlinger, author of a new book on the history of illegal drugs scheduled for publication later this year.
Gahlinger notes that exposure to constituents in marijuana seems to slow sperm in test-tube studies, "but in practice, there doesn't seem to be any difference at all" in the fertility and sexual potency of men who get high and men who don't. Likewise, he says, the flabby-chest and impotence stories lack support too.
In regard to heart disease, Gahlinger notes that no reliable research shows pot smokers are any more or less likely than nonusers to have cardiovascular problems. (The Boston study didn't compare people in the two groups.) Other illegal drugs carry far more serious health risks, he insists.
"Marijuana is one of the safest drugs ever discovered," Gahlinger says. "It's safer than aspirin."
But many physicians in this country don't share Gahlinger's mellow view. "Daily smoking of marijuana causes some of the same consequences as the smoking of tobacco," says Dr. Donald Tashkin, medical director of the pulmonary function laboratory at the UCLA School of Medicine, among them bronchitis, a persistent cough and heavy production of phlegm.
Although even regular pot smokers light up only a few times a day, Tashkin points out that joints are loosely packed and don't have filters. What's more, pot users inhale deeply and hold smoke in their lungs far longer than tobacco users. As a result, smoking a marijuana cigarette exposes the lungs to three to four times more tar than smoking a butt.
There's little data on lung cancer rates among people who smoke only marijuana, but Tashkin says that lung biopsies of regular pot users reveal the presence of pre-cancerous cells.
Last year, a study at UCLA's Jonsson Cancer Center showed that mice implanted with malignant cells develop tumors faster if they're exposed to THC. "It appears that the THC in marijuana impairs host defense--the ability to fight infection and fight cancer," Tashkin says.
He points out the irony that cancer and HIV patients, whose immune systems need bolstering, are among the loudest voices demanding medical marijuana. It's also conceivable, he says, that THC's effects could make a healthy pot smoker more vulnerable to infectious diseases, such as pneumonia.
While researchers try to clear the haze over marijuana's impact on health, a few things aren't up for debate. Driving while high is a terrible idea. "Don't do it," says Gahlinger. "You're intoxicated."
One study found that airline pilots operating flight simulators still had delayed reactions 24 hours after smoking pot. Furthermore, like it or not, the stuff is illegal. Getting busted for possession or fired for flunking a drug test are guaranteed ways to complicate your life.
Finally, no pot smoker on the planet would deny the existence of a phenomenon universally known as the munchies. Another study published in June, by researchers at the State University of New York at Buffalo, found that marijuana users eat more salty snacks and cheese than nonusers. They also eat fewer fruits and vegetables, consume greater amounts of beer and soda, and smoke more cigarettes.
Whatever you think about marijuana, you're kidding yourself if you believe that the path to better health runs through the chips-and-dip aisle at 7-Eleven.
Timothy Gower is at firstname.lastname@example.org. The Healthy Man runs the second Monday of the month.