E-cigarettes, marijuana have harmful effects on heart, UCSF study finds

SAN FRANCISCO (KRON) — A new study from University of California San Francisco researchers found evidence that e-cigarettes and marijuana have harmful effects on the heart that are similar to negative effects from traditional tobacco cigarettes.

Health effects from vapes, marijuana joints, and cigarettes all open the door to abnormal heart rhythms, according to a new study published Tuesday in the journal Heart Rhythm.

“We found that cigarettes, e-cigarettes, and marijuana greatly interfere with the electrical activity, structure, and neural regulation of the heart,” said lead author Dr. Huiliang Qiu, a postdoctoral scholar in the UCSF Division of Cardiology. “Often, any single change can lead to arrhythmia disease. Unfortunately, these adverse effects on the heart are quite comprehensive.”

Nicotine vapes and cannabis products have become popular in recent years because the public perceives them as being less harmful than smoking, researchers said. But the new findings shed light on health risks from these seemingly “safer” substances.

Researchers explained that the heart must pump blood efficiently and with correct timing. This vital organ has its own electrical control system resulting from nerves. If parts of the heart don’t correctly handle the electrical signals, then different regions of the heart act asynchronously – essentially fighting against each other, rather than functioning as a single efficient pump, resulting in arrhythmias that can be life threatening, according to researchers.

Specifically, the purpose of the study was to investigate whether the use of novel tobacco products or marijuana can cause the development of proarrhythmic substrate and eventually lead to arrhythmias.

The study writes of its methodology, “Rats were exposed to smoke from tobacco, marijuana, or cannabinoid-depleted marijuana, to aerosol from electronic cigarettes or heated tobacco products, or to clean air once per day for 8 weeks. The rats exposed to tobacco or marijuana products exhibited progressively increased systolic blood pressure, decreased cardiac systolic function with chamber dilation, and reduced overall heart rate variability, relative to the clean air negative control group.”

“It’s notable that all of these tobacco and marijuana products had such similar effects. And what’s really striking is that this was caused by a single realistic smoking/vaping session per day,” said senior author Matthew Springer, PhD, a UCSF professor of cardiology.

“The bottom line is that e-cigarettes, IQOS, and marijuana cigarettes still involve many of the potential harmful effects of smoking tobacco,” Springer said, “None of these products should be assumed to be a harmless replacement for smoking.”