Marijuana gummies, a popular type of edible cannabis, contain delta-9-tetrahydrocannabinol (THC), the compound responsible for psychoactive effects. Their increasing availability has raised questions about their safety profile, particularly concerning the heart. Understanding the potential cardiovascular risk requires examining how this ingested form of the drug differs from traditional methods of use. The core concern centers on how the body processes THC and the subsequent effects on the circulatory system, which can range from minor heart rate changes to serious cardiac events.
The Unique Cardiovascular Effects of Edibles
Edibles introduce THC through a pathway distinct from smoking or vaping, leading to a different pharmacokinetic profile. When ingested, THC is absorbed through the digestive system and undergoes hepatic first-pass metabolism in the liver. This process converts delta-9-THC into a metabolite called 11-hydroxy-THC (11-OH-THC). This metabolite is known to be more potent and effective at crossing the blood-brain barrier than delta-9-THC.
Due to this liver processing, the onset of effects is significantly delayed, often taking 30 minutes to two hours or longer. This slow onset can lead users to consume more product, resulting in unpredictable and excessive dosing. This excessive dosing prolongs systemic exposure to the potent 11-OH-THC.
Cannabinoid Interaction with Heart Function
THC affects the heart by interacting with the endocannabinoid system, specifically through CB1 receptors found in cardiovascular tissues. Activation acutely stimulates the sympathetic nervous system, triggering the “fight or flight” response. This results in a rapid increase in catecholamines (adrenaline and noradrenaline). The surge in these stress hormones drives an increase in heart rate, known as tachycardia, which can be significant and prolonged.
The effect on blood pressure can be biphasic, sometimes causing an initial drop followed by a rise. The overall result is an enhanced workload on the heart. This mechanism increases the oxygen demand of the heart muscle while CB1 receptor activation in the blood vessels can lead to reduced blood flow, creating an oxygen supply-demand mismatch.
Identifying Specific Cardiac Risks
The acute physiological changes induced by THC can translate into documented adverse cardiac outcomes, particularly in susceptible individuals. One serious risk is acute coronary syndrome, which includes myocardial infarction (heart attack). The combination of increased heart rate, elevated blood pressure, and potential vasospasm—a sudden constriction of blood vessels—can precipitate an event, even in younger users without a history of heart disease. Cannabis use has also been associated with various cardiac arrhythmias, including atrial fibrillation, and ischemic stroke, which occurs when blood flow to the brain is blocked.
Factors Increasing Vulnerability
While cannabis can affect generally healthy individuals, certain pre-existing conditions increase the risk of an adverse event. People with diagnosed or undiagnosed cardiovascular disease, such as coronary artery disease or hypertension, are more susceptible to THC’s cardiac strain. The heightened oxygen demand and rapid heart rate triggered by the drug can overwhelm a heart already compromised by narrowed arteries. Advanced age is another factor that amplifies vulnerability, as the cardiovascular system naturally becomes less resilient over time.
Concurrent use of other substances or medications that affect heart rate or blood pressure can compound the danger. Individuals who are new to cannabis or using edibles for the first time are also at an elevated risk. This is due to a lack of tolerance and the potential for accidental over-consumption resulting from the delayed onset of effects.