A team of researchers from the University of Cambridge, having analyzed data from over 100 million people, has determined that the use of cannabis, cocaine, and amphetamines significantly increases the risk of stroke. The study, published in the International Journal of Stroke, indicates that these substances are independent risk factors for stroke.
Key Findings of the Study
The results of the meta-analysis show an alarming increase in stroke risk:
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Amphetamines: Increase the risk of stroke by 122%.
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Cocaine: Increases the risk of stroke by 96%.
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Cannabis: Increases the risk of stroke by approximately 37%.
Particularly concerning are the data for individuals under 55, where amphetamine use increases the risk of stroke nearly threefold (174%), while cocaine use increases it by 97%.
Why Do These Substances Cause Strokes?
According to the researchers, these drugs trigger physiological changes in the body that directly contribute to the development of a stroke:
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Sharp increases in blood pressure.
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Vasospasm (narrowing of blood vessels).
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Cardiac arrhythmias.
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Increased probability of blood clotting (especially with cannabis).
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Inflammation of the blood vessels (vasculitis) — particularly with amphetamine use.
Genetic Connection
Unlike traditional observational studies, the scientists employed a statistical method known as Mendelian randomization. This method established that the risk is linked not only to the user’s lifestyle (e.g., poor diet or lack of exercise) but also to the direct physiological impact of the substances themselves.
Specifically, genetic evidence confirms that cocaine use is closely linked to intracranial hemorrhage (bleeding in the brain), while cannabis use is linked to strokes caused by damage to large arteries.
The authors of the study emphasize that this is the largest analysis of its kind ever conducted, providing a foundation for new public health strategies aimed at reducing drug use and, consequently, preventing strokes.
