It's a little more uniform when the product is absorbed by smoking or vaping the oil, Ward said. But, "there are obvious concerns about smoking something." A 2007 review published in the journal JAMA Internal Medicine found that smoking marijuana resulted in similar declines in respiratory system health as smoking tobacco. A similar review published in 2014 in The American Journal of Cardiology found that marijuana smoke inhalation can increase the chances of heart attack or stroke. Neither review analyzed the effects of vaping cannabis oil alone, so it's unclear if it has the same health risks as smoking other marijuana products.