Study: no link between cannabis and cardiovascular disease

A U.S. study has just to debunk a widespread belief. In fact, it found no link between cannabis use and the onset of cardiovascular diseases—those affecting the heart and blood vessels. This large-scale study, conducted among more than 56,000 American adults, was published by the journal Cureus Journal of Medical Science.

«Although the scientific literature has has been shown in the past that cannabis has a negative impact on cardiovascular health, », our study shows that cannabis use is not associated with the incidence of cardiovascular disease", note the six authors of this study. To shed light on the scientific debate, they emphasize «the need for further research on this link» the link between cannabis and heart disease.

To reach this conclusion, scientists analyzed the massive U.S. health database. Known as the Behavioral Risk Factor Surveillance System (BRFSS), this database contains all health data on Americans. It is managed by the Centers for Disease Control and Prevention, which is the equivalent of Santé Publique France in France. 

The scientists included only patients over the age of 18 who had provided information about their cannabis use and cardiovascular diseases. The researchers also note: «Age, gender, ethnicity, body mass index, income, physical activity, tobacco and alcohol use, and depression were all accounted for as potential confounding variables.»

Accounts for 0.8 % of heart attacks

This new study contradicts other studies that have linked cannabis to cardiovascular disease. One such study, conducted in 2014, led by a French female doctor. Émilie Jouanjus, Ph.D. in pharmacology at Toulouse University Hospital, stated to the Sunday Journal : «While reviewing the medical records of 200 patients hospitalized in Toulouse between 2004 and 2007, I was struck by the occurrence of heart attacks or strokes in young men, between the ages of 22 and 26, with no other specific risk factors aside from cannabis use.»

However, this study has a major methodological bias: the sample consists solely of hospitalized young people. These individuals are therefore already in poor health. In fact, Emilie Jouanjus qualified the findings of her research: «This study does not allow us to conclude that smoking cannabis increases cardiovascular risk compared to smoking cigarettes alone, but other studies do show this.»

In fact, Dr. Jouanjus’s study was not the only one. In 2011, another American study published in the prestigious British journal The Lancet  supported her position. She claimed that cannabis could account for 0.8 % of non-fatal heart attacks. However, this rate—which is relatively low—is lower than the risk associated with exposure to pollution (7 % of heart attack cases) or coffee consumption (5 %).