Cannabis use is on the rise, but new evidence highlights a crucial link between cannabis and heart disease. Understanding the impact of cannabis on cardiovascular health is essential, as more people incorporate cannabis into their lives for various reasons. This post explores what recent studies reveal about cannabis, the heart, and the associated risks, so you can make informed decisions about your health.

Why Cannabis and Heart Health Matter

Cannabis, often viewed as benign, can directly affect the health of your heart and blood vessels. Recent research suggests the risks are more significant and widespread than previously recognised. While cannabis has over 100 active compounds called cannabinoids, studies now point to tetrahydrocannabinol (THC) as a factor influencing cardiovascular health.

New Evidence Linking Cannabis to Cardiovascular Disease

The link between cannabis heart disease and overall cardiovascular health used to rely on smaller case studies, but larger epidemiological studies are changing the landscape. A 2024 US study involving over 430,000 people found that daily cannabis users had a 49% increased risk of heart attack (myocardial infarction) and were twice as likely to have a stroke compared with non-users. Importantly, this risk was present regardless of whether individuals also smoked tobacco.

Key Findings from Major Studies

• Dose-dependent risk: Weekly cannabis use was linked with a 3% higher chance of heart attack and a 5% rise in stroke risk.
• Consistent results: A 2022 analysis of 500,000 adults in the UK also tied cannabis smoking to increased heart attack rates (53% among users vs 45% for non-users).

These results indicate that cannabis cardiovascular health risks escalate with frequency of use. Even those using cannabis only weekly faced measurable risks compared to those who abstained.

How Cannabis Affects the Heart

THC, Cannabinoid Receptors, and Plaque Build-Up

THC affects specialised receptors (CB1 and CB2) found not just in the brain but also in the heart, blood vessels, and muscle cells. Binding to these receptors, THC can promote inflammation and oxidative stress within blood vessels. This process may potentially increase atherosclerotic plaque build-up. Animal studies reinforce this connection, with findings that cannabis heightens atherosclerotic changes that lead to heart disease.

Arrhythmia and Electrical Conduction

Cannabis isn’t just linked with heart attack and stroke. There’s growing concern about its relationship to arrhythmia (irregular heartbeats), especially atrial fibrillation. A 2023 European Heart Journal study showed a doubled risk for arrhythmia in medical cannabis users within six months of use compared with non-users.

Activation of cannabinoid receptors may disrupt enzymes crucial to the heart’s electrical system. Other research connects cannabis consumption to increased heart rate, vessel constriction, and even vasospasm, all of which can create a hostile environment for heart health.

Smoking vs Edibles

While research has not yet proven edibles or cannabis oils to be safer, experts suggest that inhaling burnt cannabis adds extra toxins that may worsen cardiovascular effects. However, the active compounds and risks remain present regardless of consumption method.

Observational Studies and Their Limitations

Can We Trust the Data?

Most studies examining cannabis cardiovascular health risks are observational, meaning they observe outcomes in people based on current or past behaviours. This raises questions around accuracy:

• Recall bias: Many studies rely on self-reported use. People may forget, underreport, or overestimate their cannabis consumption.
• Lifestyle confounding: Those who use cannabis may also have habits (like high-calorie diets or alcohol use) that independently elevate their cardiovascular risk.
• Medical cannabis vs recreational use: Some modern studies rely on prescription data, which is more reliable, but there remain differences between those who receive medical prescriptions and recreational users.

Despite these hurdles, the repeated association across large populations suggests a meaningful connection between cannabis and cardiovascular disease.

How Should Patients and Clinicians Respond?

Discussing Cannabis Use and Heart Disease

Although not every cannabis user will develop heart disease or stroke, the evidence points to higher risk compared with non-users. Experts increasingly advise that anyone with an existing risk for cardiovascular issues should consider abstaining from or seriously reducing cannabis use. Clinicians are encouraged to ask about both the amount and method of cannabis consumption, using information from product labels to estimate THC exposure, thanks to improved regulations and labelling.

Synthetic cannabinoids

Synthetic cannabinoids, which are often even more potent than naturally-derived THC, pose a potentially higher risk to heart health. These substances bind more tightly to receptors, increasing the likelihood of triggering adverse cardiovascular effects.

The Bigger Picture on Risk

Absolute risk may still be low for some conditions, including arrhythmia, especially among medical users who benefit from reduced pain and improved quality of life. Alternatives like opioids and NSAIDs (non-steroidal anti-inflammatory drugs) may also carry heart risks, complicating the wider treatment picture.

However, early exposure and long-term use, especially in younger populations increasingly experimenting with cannabis, could compound heart disease risk over time. This mirrors patterns seen with tobacco and cardiovascular health across decades.

Takeaways for Protecting Your Heart

There is a clear, growing link between cannabis use and heart health risks. Both heavy and weekly use can increase the chances of heart attack, stroke, and arrhythmia, especially among individuals with existing risk factors or those using high-THC products. The growing evidence means it’s important to consider not only how much cannabis you use, but also how long you plan to continue.

Anyone considering or currently using cannabis should discuss this openly with their healthcare provider, especially if they have a history of heart disease or stroke. Monitoring heart health, seeking alternatives when possible, and understanding the relative risks can help protect you in the long term.

Source: Med Scape