It’s safe to say that when it comes to cannabis and strokes, the relationship is complicated. Cardiovascular health is one of the biggest concerns among public health officials and medical cannabis researchers. Research in the past has found correlations between cannabis consumption and a greater risk of strokes. However, there has yet to be a study that provides a definitive look at whether or not cannabis consumption can increase the chances of a stroke. Some studies even suggest that cannabis treatments may be helpful for restoring health post-stroke. Curious? Here are more details.
What is a stroke?
A stroke is a medical event in which the brain is suddenly deprived of oxygen-giving blood. Without oxygen, brain cells quickly begin to die. This can be a life-threatening event. Strokes can also lead to paralysis, loss of speech, and the need for long-term rehabilitation.
The most common type of stroke is an ischemic stroke, which occurs when a clot blocks blood vessels in the brain. The second most common type of stroke is a hemorrhagic stroke, which occurs when a blood vessel in the brain ruptures. Needless to say, neither of these situations are pleasant.
Strokes can cause a variety of different symptoms, many of which significantly interfere with the ability to perform daily tasks. Some of these symptoms include:
- Intense headache
- Speech impairments, such as difficulty speaking or understanding speech
- Numbness and limited mobility on one side of the body
- Drooping face on one side
- Difficulty seeing in either one eye or both
- Difficulty or inability to walk
If you find yourself experiencing these symptoms, it is imperative to get to the emergency room as soon as possible.
What causes strokes?
Stroke is ultimately a cardiovascular and metabolic event. High blood pressure is one of the single greatest risk factors for stroke. Blood pressure that is continuously at 140/90 and above is considered high and puts constant stress on the blood vessels and heart.
The outcome of this stress is weakened blood vessels, which are more prone to rupture and blood clot formation. This increases the chance of having a stroke.
So, what causes high blood pressure? High blood pressure is also known as hypertension. There are a number of risk factors that contribute to hypertension, including both biological and lifestyle contributors. Obesity, lack of physical activity, a high-sodium diet, smoking, stress, and alcohol consumption all contribute to hypertension.
These factors will also contribute to an increased risk of stroke.
Does cannabis increase the risk of a stroke?
The relationship between cannabis and stroke is a complicated one. A study presented in spring of 2017 suggests that cannabis consumers have an increased risk of stroke when compared to non-consumers. The study examined over 20 million health records. Of those, 316,000 reported cannabis consumption.
After crunching the numbers, researchers discovered that cannabis consumers were more likely to have experienced cardiovascular complications like stroke, heart attack, heart failure, and coronary artery disease.
Those who reported cannabis consumption were also more likely to be obese, use alcohol, smoke tobacco, and have high blood pressure. All of the latter are factors which contribute to stroke.
After removing these factors, researchers still found that cannabis use was independently associated with a 26 percent increase in stroke risk and a 10 percent increase in heart attack.
There are a few problems with this study, however.
No information was reported on how the cannabis was consumed, how much, how often, or what type. Nor did the study address important variables like regular exercise, stress, genetics, or more robust lifestyle factors.
This study was also based on hospital discharge records. This means that patients included in this study may have already been sick and unhealthy. This research does not sufficiently conclude whether or not cannabis consumption is linked to stroke in the general population.
Additional study finds no link between cannabis and strokes
While this study seems quite serious, additional research has failed to find an independent correlation between cannabis and stroke. For example, a study of nearly 50,000 young adults in Sweeden found,
[…] no evident association between cannabis use in young adulthood and stroke, including strokes before 45 years of age.
However, the study did find that tobacco consumption had a dose-dependent correlation to stroke. When testing whether or not a variable like tobacco consumption is strongly linked to stroke, looking at dose is important. If there is a strong correlation between cause and effect, upping the dose of an input would lead to greater risks of developing said outcome.
Moving forward, the cardiovascular effects of cannabis will be a subject of much attention.
Already, research suggests that cannabis does have an impact on blood pressure and heart rate. In 1975 study of young male volunteers, a once-daily treatment with 210 milligrams of isolated tetrahydrocannabinol (THC), the primary psychoactive in the cannabis plant, both lowered blood pressure and heart rate. The volunteers were given the compound for five to 15 days.
Additional evidence shows that discontinuing cannabis consumption leads to a rise in blood pressure and heart rate. Further evidence still suggests that consumers can develop a tolerance to the cardiovascular effects of cannabis with repeat use.
Since cannabis has such varied effects on heart rate and blood pressure, there is a chance that certain people may be more likely to experience negative effects on the heart and vascular system with cannabis. However, it is unclear at this point who those people might be and whether or not the herb increases the risk of stroke for the average person.
Does cannabis help stroke victims?
Whether or not chronic cannabis consumption increases the risk of a stroke in otherwise healthy consumers is still unknown. Only more research will begin to unravel the effects of the herb on the cardiovascular system. However, there is a growing body of research that suggests that cannabis compounds may be helpful to those who have had a stroke.
Preclinical research suggests that cannabinoid receptors, the landing sites for THC, are over expressed in the brains of stroke victims after the big event.
Normally, the human body’s own version of THC, called endocannabinoids, connect with these cell receptors. After a stroke, an increase in the number of cannabinoid receptors suggests that brain cells are calling out for more endocannabinoids.
Cannabis compounds like THC directly engage these receptors. Another popular cannabis compound, cannabidiol (CBD), can boost the amount of the body’s own endocannabinoids. Researchers speculate that this would be helpful after stroke.
A review of scientific literature published in the Journal of Cerebral Blood Flow & Metabolism looked at pooled research from rodent and primate studies. A total of 1,473 animals were tested in 144 total experiments.
The research found that animals treated with cannabis compounds faired significantly better after stroke than those that did not. While overall survival rates did not increase in cannabinoid-treated animals, those given cannabis-like therapies showed less inflammation and greater overall functioning after a stroke.
This may not come as a surprise to many a cannabis fan, as it is well documented that cannabis contains a wealth of neuroprotective antioxidants that help the nervous system recover from stress. These animal findings are good signs that cannabis preparations may be beneficial for those trying to recover from the medical event.
How to reduce risk of a stroke
If you’re a cannabis consumer and you are concerned about your risk for stroke, there are a few things that you can do to help yourself out. Here are just a few:
- Opt for a low-temperature vaporizer over smoking
- Opt for edibles or tinctures
- Consume cannabis in lower doses or avoid excess consumption
- Exercise regularly
- Practice stress-management techniques such as breathing exercises
- Eat a healthy, plant-heavy diet
- Avoid excess alcohol consumption
- Don’t smoke tobacco