Medical Cannabis, Heart Health, and Stroke: The Pros & Cons

Total Studies on Topic

Heart Disease

6 studies

6 positive results

0 inconclusive results

0 negative results

Heart Attack

48 studies

23 positive results

22 negative results

3 inconclusive results

Cardiac Arrhythmia

37 studies

9 positive results

26 negative results

2 inconclusive results

Cardiac Fibrosis

3 studies

2 positive results

1 negative result

0 inconclusive results

Atrial Fibrillation and Atrial Flutter

11 studies

1 positive result

10 negative results

0 inconclusive results

Myocarditis

9 total studies

3 positive results

6 negative results

0 inconclusive results

Atherosclerosis

41 total studies

29 positive results

11 negative results

1 inconclusive result

Stroke/Cerebral Infarction

111 total studies

89 positive results

15 negative results

7 inconclusive results

Summary

There is a lot of contrasting evidence regarding the effects of cannabis and cannabinoids on heart health and whether cannabis use can increase the risk of stroke. Cannabis may be useful for reducing inflammation associated with myocardial ischemia (heart blockages that can lead to heart attacks) and ischemic stroke (blocked blood vessels in the brain).

However, there is also some evidence that cannabis use can increase heart rate and cause complications in those with an irregular heartbeat (arrhythmia) or atrial flutter. This can potentially increase the risk of a heart attack or stroke. [1] However, many of the negative effects of cannabis on cardiovascular health could be due to smoking it, with confounders like tobacco smoking.

It is also possible to mitigate [2] some of the harmful effects of cannabis on cardiovascular health via diet and exercise.

Pros

• One study [3] suggests that “A single ultra-low dose of THC before ischemia is a safe and effective treatment that reduces myocardial ischemic damage.”
• The terpene beta-myrcene “protects oxidative and histological damage in the heart tissue after global ischemia-reperfusion and may be [a] useful, safe alternative treatment for cardiac tissue after ischemic stroke.” [4]
• Cannabidiol (CBD) may help reduce inflammation associated with ischemic heart disease. [5]
• Beta-caryophyllene may also reduce inflammation and protect against myocardial infarction. [6]
• Medical cannabis may help manage anxiety, [7] insomnia, [8] and depression, [9] all of which increase the likelihood of suffering from heart disease.
• Medical cannabis may help manage metabolic syndrome (increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels): “Among emerging adults, current marijuana users were 54% less likely than never users to present with metabolic syndrome.” [10]

Cons

• Tetrahydrocannabinol (THC) may cause inflammation in endothelial cells [11] that line the interior of blood vessels.
• Smoking cannabis may increase the chances of heart attack or stroke in some people, especially younger people. [12]
• Cannabis use can increase blood pressure and heart rate in the short term, which can increase the likelihood of suffering from a heart attack or stroke.
• For those taking blood thinners like warfarin, CBD may interfere with its metabolization and increase warfarin levels in the bloodstream. For those who cannot tolerate blood-thinning medications such as warfarin or aspirin, CBD may be an alternative, [13] so this aspect is not always a negative.

Recommended Strains

Cannabis strains (cultivars) high in cannabidiol (CBD), cannabigerol (CBG), and tetrahydrocannabivarin (THCV) may be ideal. Examples include:

• Doug’s Varin
• Cannatonic
• Willie Nelson
• Dutch Treat
• Durban Poison
• Green Crack, aka Green Cush
• Malawi
• Tangie
• Skunk #1

Low-to-moderate THC levels may help reduce the risk of experiencing increased blood pressure and heart rate while also taking advantage of THC’s anti-anxiety (anxiolytic), anti-inflammatory, and antioxidant properties. [14]

Terpenes like myrcene, linalool, humulene, pinene, and beta-caryophyllene may also be helpful for their relaxing effects and anti-inflammatory properties. Flavonoids like naringin, quercetin, and rutin may also be helpful.

Could Medical Cannabis Help?

Overall, it seems that marijuana use has a complicated relationship with the heart and that its use can have both positive and negative effects on the organ. This applies to the likelihood of suffering from a stroke as well. There is some evidence that cannabinoids can be useful for managing the after-effects of stroke, and some studies show that smoking cannabis may increase the chances of suffering from a stroke.

Before we answer some of the main questions surrounding cannabis, heart health, and stroke, it is worth keeping the following factors in mind:

• What other health problems does the person with heart issues have?
• How old is the patient?
• How active is the patient, and what is their diet like?
• What route of administration are they using? Are they smoking cannabis or using a tincture or topical?

Such factors can impact the effect cannabis has on heart health.

Does cannabis cause strokes? Does cannabis have any neuroprotective effects that could help manage traumatic brain injuries (TBIs) or strokes?

Traumatic brain injuries (TBIs) and strokes are two different conditions, but both involve brain neurotoxicity and cell death, so treatment has similarities. Medical cannabis contains several phytocannabinoids (plant cannabinoids) with antioxidant, neuroprotective, and possible neurogenic properties that could potentially be helpful for TBIs.

There is mixed evidence on cannabis and whether or not it can cause strokes or help manage the aftereffects of suffering one. Several studies show a correlation [15] between the use of cannabis (in particular, smoking it) and the likelihood of suffering a stroke, but, as they say, correlation does not necessarily mean causation. [16] There are many factors to account for, including diet, tobacco smoking, activity levels, and previous TBIs.

Similarly, several studies show that cannabinoids like cannabidiol (CBD) and cannabigerol (CBG) have neuroprotective effects [17] that could help treat acute brain damage. The roots of the cannabis plant also contain a type of phytosterol that may help lower cholesterol, called beta-sitosterol, which could help reduce the chances of stroke if consumed regularly.

Again, whether cannabis can increase the likelihood of stroke or potentially manage the aftereffects of one is not known.

Can cannabis cause heart disease?

Heart disease is an umbrella term used for many different kinds of problems, including cardiovascular diseases (CVDs) and conditions that affect your heart’s muscle and valves or cause abnormal rhythms (arrhythmias). Different conditions may therefore require different approaches when it comes to cannabis.

Medical cannabis and cannabinoids may help reduce inflammation and blood/heart rate when dosed appropriately, but there are some other, less direct ways medical cannabis may help treat heart diseases. These include:

• Managing anxiety, insomnia, and depression, all of which can contribute to the likelihood of suffering from a heart disease.
• Managing metabolic syndrome (increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels).
• Managing any aches and pains that may prove detrimental to physical activity.

What about chronic ischemic heart disease? Does cannabis help?

Chronic ischemic heart disease is the term given to heart problems caused by narrowed heart arteries, which means less blood and oxygen get into the heart. This can cause chest pain (angina) and heart attacks.

There are six studies in our Leafwell database (5,337 studies) on medical cannabis for chronic ischemic heart disease (five animal studies and one meta-analysis). All studies show positive results, although it must be said that these are mostly studies on animals.

As for the reasons why medical cannabis seems to help with ischemic heart disease, it seems that cannabinoids play a protective role, in a similar way to how cannabinoids may protect against traumatic brain injuries (TBIs), i.e., they have anti-inflammatory and antioxidative properties.

Can cannabidiol (CBD) help prevent or treat heart problems?

CBD’s anti-inflammatory and antioxidative properties may be able to reduce risk factors that can lead to heart disease (e.g., high blood pressure), but there is no definitive evidence for this.

Can THC increase heart rate?

Those who do not have much tolerance to THC may find that it increases their heart rate. This is because THC turns on the sympathetic nervous system and stimulates the production of cortisol, which can increase anxiety and elevate your heart rate.

However, over time, stress receptors become blunted to cortisol, and the relaxing, sedative effects of THC start to take over. This can make medical cannabis useful for managing anxiety and post-traumatic stress disorder (PTSD) when dosed appropriately.

This is why it is important to go slow and low with cannabis and build tolerance over time, especially THC-rich plants and products.

Conclusion

It seems that medical cannabis can be both helpful and harmful when it comes to heart health and stroke. The evidence points both ways. Which precise heart problem you are trying to manage with medical cannabis makes a difference. Route of administration matters as well, with many of the potential harms resulting from inhaling smoke.

Overall, the evidence suggests that medical cannabis may be useful for managing cardiovascular problems associated with metabolic disorders but perhaps less useful when it comes to problems that involve an elevated or irregular heartbeat. There is a lot of debate on whether cannabis can increase or decrease blood pressure and hypertension, with the consensus so far saying that using cannabis can increase blood pressure in the short term but decrease it in the long term. This may be one reason why there are so many mixed results when it comes to strokes. [18]

References

[1] Centers for Disease Control and Prevention (CDC), ‘Marijuana and Public Health’, October 19, 2020. https://www.cdc.gov/marijuana/health-effects/heart-health.html

[2] Conger, Krista, ‘Marijuana linked to heart disease; supplement may mitigate risk, study reports’, Stanford Medicine, April 29, 2022.

[3] Waldman M, Hochhauser E, Fishbein M, Aravot D, Shainberg A, Sarne Y. ‘An ultra-low dose of tetrahydrocannabinol provides cardioprotection’. Biochem Pharmacol. 2013 Jun 1;85(11):1626-33. doi: 10.1016/j.bcp.2013.03.014. Epub 2013 Mar 26. PMID: 23537701.

[4] Burcu GB, Osman C, Aslı C, Namik OM, Neşe BT. ‘The protective cardiac effects of Β-myrcene after global cerebral ıschemia/reperfusion in C57BL/J6 mouse’. Acta Cir Bras. 2016 Jul;31(7):456-62. doi: 10.1590/S0102-865020160070000005. PMID: 27487280.

[5] Durst R, Danenberg H, Gallily R, Mechoulam R, Meir K, Grad E, Beeri R, Pugatsch T, Tarsish E, Lotan C. ‘Cannabidiol, a nonpsychoactive Cannabis constituent, protects against myocardial ischemic reperfusion injury’. Am J Physiol Heart Circ Physiol. 2007 Dec;293(6):H3602-7. doi: 10.1152/ajpheart.00098.2007. Epub 2007 Sep 21. PMID: 17890433.

[6] Younis NS, Mohamed ME. ‘β-Caryophyllene as a Potential Protective Agent Against Myocardial Injury: The Role of Toll-Like Receptors’. Molecules. 2019;24(10):1929. Published 2019 May 19. doi:10.3390/molecules24101929. PMC6572120.

[7] McCann, Una D., ‘Anxiety and Heart Disease’, Johns Hopkins Medicine. Retrieved February 7, 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/anxiety-and-heart-disease

[8] Centers for Disease Control and Prevention (CDC), ‘How Does Sleep Affect Your Heart Health?’ January 4 2021. https://www.cdc.gov/bloodpressure/sleep.htm

[9] National Institute of Health (NIH), ‘Heart disease and depression: A two-way relationship’. April 16, 2017. https://www.nhlbi.nih.gov/news/2017/heart-disease-and-depression-two-way-relationship

[10] Vidot DC, Prado G, Hlaing WM, Florez HJ, Arheart KL, Messiah SE. ‘Metabolic Syndrome Among Marijuana Users in the United States: An Analysis of National Health and Nutrition Examination Survey Data’. Am J Med. 2016 Feb;129(2):173-9. doi: 10.1016/j.amjmed.2015.10.019. Epub 2015 Nov 5. PMID: 26548604; PMCID: PMC4718895.

[11] Deng, L., Leng, B. & Nie, X. ‘The cannabis paradox: contrasting role for marijuana in cardiovascular disease.’ Sig Transduct Target Ther 7, 309 (2022). https://doi.org/10.1038/s41392-022-01160-2.

[12] Goyal H, Awad HH, Ghali JK. ‘Role of cannabis in cardiovascular disorders’. J Thorac Dis. 2017;9(7):2079-2092. doi:10.21037/jtd.2017.06.104

[13] Grayson L, Vines B, Nichol K, Szaflarski JP; UAB CBD Program. ‘An interaction between warfarin and cannabidiol, a case report’. Epilepsy Behav Case Rep. 2017;9:10-11. Published 2017 Oct 12. doi:10.1016/j.ebcr.2017.10.001. PMC5789126.

[14] Kopustinskiene DM, Masteikova R, Lazauskas R, Bernatoniene J. ‘Cannabis sativa L. Bioactive Compounds and Their Protective Role in Oxidative Stress and Inflammation’. Antioxidants. 2022; 11(4):660. https://doi.org/10.3390/antiox11040660

[15] Mateo I, Pinedo A, Gomez-Beldarrain M, et al. ‘Recurrent stroke associated with cannabis use’. Journal of Neurology, Neurosurgery & Psychiatry 2005;76:435-437. https://jnnp.bmj.com/content/76/3/435

[16] Carmela V. San Luis, Christa O’Hana S. Nobleza, Shashank Shekhar, Rebecca Sugg, Darren J. Villareal, Tapan Mehta, Shreyas Gangadhara, ‘Association between recent cannabinoid use and acute ischemic stroke’.

Neurol Clin Pract. Aug 2020, 10 (4) 333-339; DOI: 10.1212/CPJ.0000000000000888. https://cp.neurology.org/content/10/4/333

[17] Maroon J, Bost J. ‘Review of the neurological benefits of phytocannabinoids’. Surg Neurol Int. 2018;9:91. Published 2018 Apr 26. doi:10.4103/sni.sni_45_18. PMC5938896.

[18] ‘Does Using Marijuana Affect a Person’s Risk of Stroke?’ American Academy of Neurology. June 3, 2020.