New research says smoking pot may be less likely to cause bladder cancer than smoking cigarettes.

The finding is potentially valuable, the study authors said, given the ongoing debate over legalizing marijuana for medical purposes.

But one urologist not involved with the study was skeptical of the finding, and noted that nonsmokers weren’t among the men included in the study.

For the study, the researchers compared the risk of bladder cancer in more than 83,000 men who smoked cigarettes only, marijuana (cannabis) only, or both substances. The investigators found that men who only smoked pot were the least likely to develop bladder cancer over the course of 11 years.

‘Cannabis use only was associated with a 45 percent reduction in bladder cancer incidence, and tobacco use only was associated with a 52 percent increase in bladder cancer,’ said study author Dr. Anil A. Thomas, a fellow in urology at Kaiser Permanente Medical Center in Los Angeles.

Smoking both tobacco and marijuana raised the risk of bladder cancer, but less so than for those who only smoked tobacco, Thomas found. He presented the findings Monday at the American Urological Association annual meeting in San Diego.

Dr. Karim Chamie, an assistant professor of urology at the David Geffen […]