Snoop Dogg, who these days hangs out with Martha Stewart, says he first smoked marijuana when he was 8 or 9 years old.

That's younger than national statistics account for, but we do know that from 2006 to 2013, among adults 50 and older the number of folks who've used marijuana in the past year increased 71.4%.

But it's not all fun and games. And anyone who smokes marijuana should listen up.

According to a study out of Colorado published in the Journal of the American Osteopathic Association, pot smokers who go into surgery may require up to three times as much anesthetic to become sedated as someone who isn't getting high regularly.

That's very risky: Pumping more anesthesia into a person can lead to suppressed breathing and low blood pressure — and it can interfere with post-op recovery.

This has led the American Association of Nurse Anesthetists to update treatment guidelines to highlight risks to marijuana users. Doctors are urging patients in every state — whether pot's legal or not — to let them know if the patient has smoked or ingested pot.

That's because it's important to stop smoking well ahead of surgery. The best data we have is that screening tests for marijuana can detect its use in someone smoking for the first time for about three days; for someone who smokes three to four times weekly, it's five to seven days; and for once-a-day or more frequent users, it can be detected for 30 days or longer.