Study Links Long-Term Cannabis Use to Increased Heart Disease Risk

Recent research reveals a concerning correlation between long-term cannabis consumption and heightened risks of heart disease. A study conducted by researchers at UC San Francisco indicates that the effects of consuming edible cannabis, like gummies, can match the cardiovascular risks linked to smoking marijuana.

Published in JAMA Cardiology on May 28, the study highlights how both forms reduce blood vessel function, a significant finding for public health.

Research Overview and Methodology

The research team studied 55 participants aged between 18 and 50, all of whom appeared outwardly healthy at the start. They categorized the participants into three groups based on their cannabis consumption habits. One group smoked marijuana regularly, another group consumed THC-infused edibles, while the last group consisted of non-users.

Each cannabis user reported consuming the substance at least three times a week for a minimum of one year. On average, smokers had maintained this habit for ten years, contrasting with the five-year average among edible users.

In September 2024, researchers conducted tests to assess the function of participants’ blood vessels and the condition of the cells lining these vessels. This comprehensive testing aimed to determine how cannabis use impacted vascular health.

Findings on Vascular Function

It was discovered that all cannabis users experienced decreased vascular function, a condition comparable to that observed in tobacco smokers. Specifically, blood vessel function in cannabis users was approximately 50% lower than in non-users.

This impairment has been linked to an elevated risk of serious cardiovascular issues, including heart attacks and high blood pressure. The study emphasized the severe implications cannabis consumption may have on heart health.

Distinct Mechanisms at Play

Interestingly, while both smoking marijuana and consuming edibles compromised vascular function, researchers noted they likely do so through different mechanisms. The participants who smoked marijuana displayed changes in their blood serum that adversely affected the cells lining both blood vessels and lymphatic vessels, a response that was not observed in those who consumed edibles.

The research concluded that chronic cannabis smoking and THC ingestion both resulted in endothelial dysfunction, a condition involving impaired functioning of the cells lining blood vessels. However, the exact pathways leading to this dysfunction appeared to differ between the two consumption methods.

Expert Opinions on the Study

Dr. Bradley Serwer, a cardiologist based in Maryland, expressed that the findings do not surprise him. He remarked that previous knowledge about the negative health consequences of chronic THC use aligns with the current study outcomes. As an expert not involved in the research, Dr. Serwer emphasized the importance of understanding these potential risks.

The study acknowledged certain limitations in its scope. Variability in cannabis strains presents challenges in standardization, while self-reported usage may introduce bias. Participants were questioned multiple times throughout the study process to improve the accuracy of their consumption reporting.

Furthermore, the researchers highlighted difficulties in assessing whether external lifestyle factors, such as stress, caffeine intake, or secondhand smoke exposure, could also influence blood vessel function.

Limitations of the Study

Dr. Serwer pointed out the trial’s limitations, noting the small sample size of just 55 participants all residing in the San Francisco Bay area. He raised concerns about the variability in cannabis strains and reliance on self-reported survey data, which may lead to under- or over-reporting of cannabis use.

The study focused on physiological endpoints rather than hard outcomes like heart attacks or strokes. This approach necessitates inferring that abnormal physiological indicators could eventually result in cardiovascular events.

Advisories from Medical Experts

Despite these limitations, Dr. Serwer concurs with the study’s overarching conclusion that cannabis use entails health risks. He urges individuals to consider the cardiovascular implications before deciding to consume cannabis. While there are known therapeutic benefits to cannabis, Dr. Serwer emphasizes that users should weigh these against potential risks.

In his practice, he advises patients to remain vigilant about any unnecessary cardiac risks. He stresses the importance of healthcare providers assessing both the benefits and risks associated with any medication or intervention. If potential risks overshadow benefits, he recommends avoiding the substance in question.

The Path Forward for Cannabis Research

This study, primarily funded by the National Institute on Drug Abuse, the California Department of Cannabis Control, and several other health institutions, serves as a critical reminder of the need for ongoing research into the long-term effects of cannabis use. It sheds light on the potential cardiovascular dangers associated with both smoking marijuana and consuming cannabis edibles.

Progress in understanding cannabis impacts on health could inform better practices and guidelines, especially as cannabis becomes more widely accepted and used for both medicinal and recreational purposes. As the conversation surrounding cannabis continues to evolve, so must the research to ensure public health remains a priority.