Cannabis, Heart Attacks and Strokes

Facilitating recovery from a stroke or heart attack is a significant challenge for physicians, yet evidence suggests that cannabinoids may have a role to play in helping patients recuperate.

Though large-scale clinical trials on this topic are still missing, smaller studies have highlighted the utility of the antioxidant properties of cannabidiol (CBD) and tetrahydrocannabinol (THC).

Cannabinoids And Stroke

Despite a lack of studies on human patients, preclinical data indicates that cannabinoids may assist in the recovery process following a stroke. In 2014, a major systematic review identified 34 studies involving 144 different experiments on animals, all of which pointed towards a significant therapeutic effect[i].

Though methodologies differed between these studies, the totality of the data indicated that all subclasses of cannabinoids helped the brains of animals recover when administered shortly after a stroke. Synthetic cannabinoids, those derived from cannabis plants, and those produced within the animals’ bodies all helped reduce brain infarct size.

The majority of strokes are ischemic, which means they occur following a reduction in blood flow to the brain due to a narrowing or blockage of blood vessels. Ischemia can be permanent or transient, depending on whether or not the restricted blood flow resolves itself naturally. According to the studies included in the review, cannabinoids effectively prevent tissue damage in the brain regardless of whether ischemia is permanent or transient.

Conventional treatments for stroke involve blood thinners to remove clots from around the brain, followed by reperfusion therapy to restore blood flow and prevent brain damage. Similarly, patients who suffer heart attacks may undergo reperfusion to boost blood flow through blocked arteries.

However, this type of treatment can sometimes lead to Ischaemia-Reperfusion Injury (IRI), whereby the sudden restoration of blood flow to ischaemic tissues actually causes more damage to cells.

Cannabinoids May Prevent IRI After Stroke Or Heart Attack

The mechanisms that lead to IRI are poorly understood, although scientists believe that oxidative stress following the restoration of blood flow may be to blame. Therefore, a recent study sought to determine if cannabinoids can be used to prevent IRI after reperfusion therapy.

The study authors treated isolated rat hearts and human heart cells with THC and found that this significantly protected both from IRI. This protective effect was partially mediated by a decrease in oxidative stress and completely restored heart mechanical function[ii].

Further analysis revealed that the addition of THC boosted the activity of key enzymes that enable heart cells to continue respiring in ischaemic conditions. The cannabinoid also prevented cells from becoming physically deformed during reperfusion, enabling cellular functions to continue normal and limiting cell death.

Findings like these strongly suggest that cannabinoids may help to enhance existing treatments for stroke and heart attack. Yet, it’s important to note that smoking weed is unsafe following a medical emergency. With a little more research, though, cannabis-based therapies could one day be used to boost the efficacy of recovery protocols.

[i] England TJ, Hind WH, Rasid NA, O’sullivan SE. Cannabinoids in experimental stroke: a systematic review and meta-analysis. Journal of Cerebral Blood Flow & Metabolism. 2015 Mar;35(3):348-58. – https://journals.sagepub.com/doi/full/10.1038/jcbfm.2014.218

[ii] Banaszkiewicz et al., Δ9-Tetrahydrocannabinol (Δ9-THC) Improves Ischemia/Reperfusion Heart Dysfunction and Might Serve as a Cardioprotective Agent in the Future Treatment, Frontiers in Bioscience-Landmark, 2022 – https://www.imrpress.com/journal/FBL/27/4/10.31083/j.fbl2704114/htm

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