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Is Marijuana Good or Bad for the Heart in Ohio?


The effects of marijuana on the mind and body have been well documented, but there is still plenty of stuff we have yet to find. One such up and coming area of research is the effect marijuana has on the heart, one of the most vital organs in the body. Combine this upswing in research with heightened public interest in general health and the importance of this research grows even more. In this article, we will look at what the heart does and how marijuana can have far-reaching effects on the cardiovascular system.

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What Does the Heart Do and How Does it Work?

Generally, the main function of the heart is to pump blood. No surprises there. To do this, the cardiovascular system can be divided into two circuits; the pulmonary circuit and the systemic circuit. 

The pulmonary circuit begins in the right atrium of the heart. Blood is fed into the atrium via the Vena Cava, the large vein on the right side of the heart. The atrium then pushes the deoxygenated blood into the right ventricle. The ventricle contracts, sending blood into the pulmonary artery to pick up oxygen in the lungs, then back through the pulmonary vein to the left side of the heart. 

The left side of the heart is generally bigger and stronger than the right side, and that’s good, considering the left side of the heart is responsible for pumping the blood through almost sixty thousand miles of arteries, capillaries, and veins in the average human body. After bringing hormones, oxygen, immune cells, and more to the necessary tissues, the blood returns to the right side of the heart to start the process again. 

This is a big, important job, and the heart cannot stop doing it. This is important, and means that it must keep beating, whether or not you are consciously controlling it. It’s similar to breathing, digesting food, and other bodily functions that must be done unconsciously. This is controlled by the medulla oblongata, a small bump between the spine and brain. The medulla is also responsible for controlling breathing and certain reflexes. 

Another, lesser known, function of the heart is as an endocrine organ. First discovered in the 1970’s and early 1980’s, some cells in the heart produces a hormone called atrial natriuretic factor (ANF). ANF, also known as ANP, helps regulate blood volume and blood pressure by causing more water to be excreted by the body and the blood vessels to dilate. The heart also produces a hormone confusingly named brain natriuretic peptide (BNP), which also works to control blood pressure. 

More information on the heart and how it works can be found at the Mayo Clinic and NIH.

How Does Marijuana Affect the Heart?

The reasons for consuming marijuana vary, but recently a huge amount of people have begun to do so for medicinal purposes. Luckily, research surrounding marijuana and its therapeutic effects has been ramping up and getting more mainstream. 

While research on marijuana and the heart is not as numerous as, say, marijuana and tumor suppression, there are still many useful studies to look at. Some of which outlines the links between the endocannabinoid system and the cardiovascular system. Cannabinoid receptors have been found in the heart and it has been hypothesized that they help regulate heart rate and blood pressure [1]. THC and other endocannabinoids may also cause vasodilation [2] and the endocannabinoid system has been shown to have protective roles in certain heart cells [1].

Unfortunately, marijuana has also been linked to some worse outcomes as well. It’s been found that smoking marijuana can elevate the user’s heart rate between twenty and one hundred percent [3]. It has been hypothesized that this is caused by THC induced vasodilation, like we previously discussed. Another study also found that young patients who use marijuana may be at a higher risk for developing atrial fibrillation [4]. Some researchers believe that marijuana may change the natural electrical rhythm of the heart and how blood flows through the heart’s coronary arteries, causing problems. 

Some studies go so far as to link marijuana and heart attacks in a small number of people, though the reason for this is still not known. For example, one study found that marijuana increased the risk of heart attack directly after ingestion by about five times [5]. Other studies have linked THC use to peripheral vascular disease due to blood vessel toxicity [6] or induced vasoconstriction [7].

On a lighter side, other studies show marijuana in a more positive light. One study followed about four thousand heart attack survivors and found no statistically significant link between marijuana use and morbidity [8]. Other studies also point to uses for marijuana that indirectly benefit the heart, such as helping tobacco smokers quit. It was shown in one study that tobacco smokers given cannabidiol reduced smoking by forty percent compared to a placebo group [9]. Marijuana has also been linked with smaller waist circumference and lower obesity rates [10][11].


Marijuana and heart health are complicated subjects and its use has been linked to both positive and negative outcomes. It is worth noting that many of the studies pointing to an increased risk of ischemia and fibrillation found only slightly increased risk and more research is necessary to find a direct link. If you are considering getting a recommendation for medical marijuana it is critical to tell your physician about any preexisting conditions that may put you at risk.