Using cocaine can almost double your risk of suffering a stroke, while cannabis and amphetamines are also on the danger list, a Cambridge study has found.
Data from more than 100 million people was examined in what scientists say is the most comprehensive analysis into the effects of recreational drug use and its links to strokes.
The investigation, which looked at 32 previous studies, found that cocaine use was linked with a 96 per cent increased risk of going on to suffer a stroke in later life compared with someone who never used the narcotic. For amphetamines, the link was even stronger, with a 122 per cent increased risk.
A link was also found with cannabis, users of which were 37 per cent more likely than non-users to go on to suffer a stroke.
When the analysis was limited to people aged under 55, the increased risk for cocaine was about the same, at 96 per cent, while for cannabis it was 14 per cent higher and for amphetamines it was 174 per cent higher. The lower risk for younger cannabis users suggests that an increased danger of strokes is likely to come from long-term use.
The researchers from the University of Cambridge noted that 8.8 per cent of the population in England and Wales aged between 16 and 59 — some 2.9 million people — told a 2024 survey that they had used a recreational drug in the previous year.
The scientists also looked at genetic variants to see whether the drug use could be a contributing cause of the strokes or whether the link could simply be coincidental. Their “evidence suggests a causal link, rather than just correlation”, they said.
• Dr Mark Porter: I’d happily keel over from a stroke in my nineties. I fear one now
Cocaine use was more strongly linked with brain haemorrhages and cardioembolic strokes, caused by a clot forming in the heart that travels to the brain. Cannabis use was more strongly associated with strokes caused by blockages in large arteries.
Excessive alcohol consumption was also linked with a heightened stroke risk. Nicotine addiction and opioid use did not show any association with stroke risk.
When assessing why there might be a link between drug use and strokes, researchers said their use had been linked with “sudden spikes in blood pressure, blood vessel spasm and constriction, heart rhythm problems, increased blood clotting — especially [with] cannabis — and inflammation or vasculitis, especially [with] amphetamines”.
Megan Ritson, a co-author of the study from Cambridge’s stroke research group, said: “This is the most comprehensive analysis ever conducted on recreational drug use and stroke risk and provides compelling evidence that drugs like cocaine, amphetamines and cannabis are causal risk factors for stroke. These findings give us stronger evidence to guide future research and public health strategies.”
The research, which was funded by the British Heart Foundation and published in the International Journal of Stroke, “suggests that it is these drugs themselves that increase the risk of stroke, not just other lifestyle factors among users”, Eric Harshfield, another co-author, said. “Taken together, our findings emphasise the importance of public health measures to reduce substance abuse as a way of helping also reduce stroke risk.”