Do you have the heart to safely smoke pot? Maybe not, a growing body of medical reports suggests.

Currently, increased smoking of marijuana in public, even in cities like New York where recreational use remains illegal (though no longer prosecuted), has reinforced a popular belief that this practice is safe, even health-promoting.

“Many people think that they have a free pass to smoke marijuana,” Dr. Salomeh Keyhani, professor of medicine at the University of California, San Francisco, told me. “I even heard a suggestion on public radio that tobacco companies should switch to marijuana because then they’d be selling life instead of selling death.”

But if you already are a regular user of recreational marijuana or about to become one, it would be wise to consider medical evidence that contradicts this view, especially for people with underlying cardiovascular diseases.

Compared with tobacco, marijuana smoking causes a fivefold greater impairment of the blood’s oxygen-carrying capacity, Dr. Keyhani and colleagues reported.

In a review of medical evidence, published in January in the Journal of the American College of Cardiology, researchers described a broad range of risks to the heart and blood vessels associated with the use of marijuana. [Read More @ The NY Times]