Which is harder on the heart, pot or tobacco?

Smoking pot might harm your heart health and that of the people around you — perhaps even more than cigarettes, a new animal study suggests.

Lab rats experienced a severe reduction in their blood vessel function after a minute’s exposure to secondhand smoke from either tobacco or marijuana, researchers said.

But it took the rats three times longer to recover from a minute of secondhand marijuana smoke, compared with tobacco smoke, the researchers found.

“If people think marijuana smoke is somehow exempt from the harmful effects of tobacco and many other kinds of smoke, this is evidence that it is not,” said study senior author Matthew Springer, a professor of medicine in the division of cardiology at the University of California, San Francisco.