A new study claims that smoking pot increases the risk of heart attacks.
Researchers at the Harvard School of Public Health and Boston's Beth Israel Medical Center questioned 3882 heart-attack victims across the US. They found that 124 of them were pot smokers, and that 37 of them had their heart attack within a day of smoking pot, including 9 within the hour after. They concluded that the risk of heart attack increased five-fold during the first hour after toking.

Yet their calculations are questionable. If the 37 tokers used pot at least every second day then their heart attacks would of necessity been within a day of smoking, even if there were no connection at all. And over two-thirds of the 124 pot-smoking heart attack victims had their attacks without having toked for over 24 hours.

Also, the 124 tokers make up only 3% of the total heart-attack victims, while they make up 4-7% of the US general population. This indicates that pot-smoking is correlated with a slightly lower risk of heart attacks.

Even if their claims are accurate, researchers admit the risk is negligible. They explained that the risk of a joint inducing a heart attack in a healthy 50-year-old is about 1 in 100,000. For a 20-year-old, the risk is much lower.