Marijuana and Heart Health: The Known and Unknown

The potential health risks and health benefits of marijuana, including chronic pain relief, epileptic seizure reduction, and cancer treatment, have long been the focus of intense debate. In the United States, 30 states and the District of Columbia currently have laws legalizing marijuana in some form. With more states legalizing marijuana use, the potential effects of marijuana and heart health must be considered. Let's look at what researchers have discovered so far.

What Is Marijuana?

Marijuana is a combination of the dried flowers of the Cannabis sativa plant. The active ingredient in marijuana is tetrahydrocannabinol (THC), found in the resin created by the leaves and buds of the cannabis plant. Marijuana contains 500 other chemicals and THC-related compounds, called cannabinoids. Marijuana can be smoked, vaporized, brewed into a tea, and mixed into foods.

Cardiovascular Effects

Many bodily tissues have THC receptors, so marijuana can affect nearly every organ in your body. One way marijuana affects the cardiovascular system is via the THC receptors in the heart that are related to contractility. The effects of marijuana on the cardiovascular system include:

• Increased resting heart rate
• Blood vessel dilation
• Blood pressure changes
• Increased cardiac output

These effects may be involved in developing heart attacks or strokes. Additionally, marijuana smoke can cause airway inflammation, wheezing, chest tightness, and damage to small blood vessels in people with existing heart and circulatory problems.

Marijuana and Heart Health Research

Until recently, marijuana was illegal throughout the United States, so rigorous scientific studies establishing dosage, safety, and efficacy were limited. When it comes to marijuana and heart health, research on the risks has only recently started emerging.

A recent American Heart Association study shows that in stressful situations, people with a history of heart disease who also use marijuana tend to develop stress cardiomyopathy and chest pain sooner than nonusers. Another study, reported by Harvard University, reported that those with a history of heart disease have a higher heart attack risk an hour after smoking marijuana than nonusers.

The latest research indicates that smoking marijuana is linked to a considerably increased risk of cardiovascular events like stroke, heart failure, coronary artery disease, and sudden cardiac death. The study, which examined more than 20 million medical records of adults aged 18 to 55, found, after adjusting for other factors, that people who reported using marijuana had a 26 percent higher risk of stroke and a 10 percent higher risk of developing heart failure.

Future Research

While many of the health benefits of marijuana have been widely noted, much more research is needed to identify health risks. Many of the current findings involving marijuana and heart health risks make it difficult to isolate the effects of the cannabinoid compounds from the cardiovascular dangers.