Study: Frequent use of cannabis increases the risk of coronary heart disease

Cannabis is becoming increasingly popular internationally, both for medicinal and recreational purposes, but a new American scientific study warns that frequent use poses risks to the heart.

People who use cannabis (marijuana) daily have a 34% greater risk of coronary artery disease, compared to those who have never been users.

The researchers, led by Dr Isan Paranjipe from Stanford University in California, who presented the research at the World Congress of Cardiology in the US, studied data on 175,000 people. Daily cannabis use was found to increase the risk of coronary heart disease by about a third, while less frequent use did not increase the risk much. The research did not differentiate between different forms of cannabis use.

"We found that cannabis use is associated with coronary heart disease, and it appears that the more frequent the use, the greater the risk to the heart. From a public health point of view, the study shows that there are probably some harmful effects of cannabis that have not been recognized until now and it is something that people should be aware of," said Dr Paranjipe.

As cannabis moves toward legalization in more US states and countries, new research highlights its potential long-term cardiovascular effects. Coronary heart disease is the most common form of heart disease and occurs when the arteries that supply blood to the heart become narrowed due to the formation of cholesterol plaques within them. The disease causes chest pain and fatigue which can lead to a heart attack.

Previous smaller studies have provided evidence that smoking cannabis can increase the risk of heart attack, stroke and other cardiovascular events, especially in young people, a new larger study confirms. Cannabis use disorder is a recognized psychiatric disorder that involves frequent use and dependence on cannabis.

Tetrahydrocannabinol (THC), the psychoactive molecule in cannabis, acts on cell receptors found in the central system, heart and blood vessels. This action eases inflammation and accumulation of plaques in the arteries, as a result it causes coronary disease. However, the same effect does not necessarily occur with cannabidiol (CBD), another active ingredient in cannabis, which is usually included in products that do not contain tetrahydrocannabinol.