Dirty habit followed by 18 million Americans doubles risk of sudden heart disease death

People who use marijuana are putting themselves at up to twice the risk of having a heart attack, stroke or dying from heart disease.

University of California researchers reviewed 24 studies involving 200million people to investigate the relationship between weed and cardiovascular disease, stroke and acute coronary syndrome (ACS) – a group of heart conditions in which there is reduced or blocked blood flow to the heart, such as a heart attack. 

They found there was a 29 percent higher risk of ACS, a 20 percent higher risk for stroke and double the risk of dying from cardiovascular disease, which includes coronary artery disease, heart failure and irregular heartbeats. 

Cardiovascular disease is America’s number one killer and nearly 1million people die of it every year. 

Because of its harmful side effects, the researchers are calling on regulators to treat marijuana like tobacco – not criminalized, but highly discouraged – and raise awareness of the risks to people who are exposed to marijuana smoke secondhand.

The CDC estimates about 52 percent of Americans have ever tried marijuana at least once and a 2024 study found nearly 18 million people use it daily or near-daily, an increase from about 1 million three decades ago.  

The researchers wrote: ‘Legalizing the drug and expanding its medical use worldwide have likely contributed to profound changes in the general perception of cannabis and to the overall rise in cannabis consumption.’

However, they warned the study ‘raises serious questions about the assumption that cannabis imposes little cardiovascular risk.’

Nearly 18million people use marijuana daily or near-daily, an increase from about 1million three decades ago (stock image)

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In the United States, marijuana is fully legal – for recreational and medicinal use – in 29 states. It is fully illegal in four states.

Laws in the remaining states are mixed, meaning the drug may be permitted for medicinal use, allowed only in the form of CBD oil, be decriminalized or be a combination of these.

Included in the studies, which ranged from 2016 to 2023, were people 19 to 59 years old. 

A noted limitation of the study was that marijuana use was self-reported on a variety of scales, meaning it was hard to measure how much marijuana use was associated with the risks.

The researchers also didn’t specify if the marijuana exposure was from smoking the drug or other forms of consumption. 

However, a similar study published in the journal JAMA Cardiology last month found people who smoked marijuana or took edibles at least three times a week had damage to their blood vessels, which are vital for delivering oxygen and nutrients from the heart to every organ and tissue.

This affects the blood vessels ability to dilate, raising the risk of arterial plaque, heart attacks and strokes.

The study found marijuana smokers had a 42 percent reduction in vascular function than controls, while THC edible users had a 52 percent reduction compared to those who never used cannabis. 

While previous studies have linked cannabis smoking to heart disease, the May 2025 study was one of the first to show heart damage from edibles containing THC, the psychoactive component of cannabis. 

The most recent study, published in the journal Heart, stated: ‘Considering the current situation and recent trends in cannabis use, the need to specifically address these recent developments was critical.’

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Based on their findings, the team concluded marijuana use should be included in doctor-patient discussions when it comes to cardiovascular disease and death risk and prevention. 

They said: ‘Cannabis needs to be incorporated into the framework for prevention of clinical cardiovascular disease. So too must cardiovascular disease prevention be incorporated into the regulation of cannabis markets. Effective product warnings and education on risks must be developed, required, and implemented.

‘Cardiovascular and other health risks must be considered in the regulation of allowable product and marketing design as the evidence base grows. Today that regulation is focused on establishing the legal market with woeful neglect of minimizing health risks.’

Researchers noted several limitations, however, including a bias in most of the included studies, lack of information or missing data and imprecise measures of cannabis exposure. 

Additionally, most of the included studies were observational and several used the same data. 

They added that ‘how these changes affect cardiovascular risk requires clarification’ and further research is needed on ‘cannabis-related adverse events.’