Smoking causes inflammation in blood vessels that increases the risk of blood clots forming, which in turn increases the risk of stroke.
Young men who smoke are more likely to have a stroke before age 50 than their peers who avoid tobacco, a small study suggests.
Smoking has long been linked to an increased risk of stroke in older adults, but research to date examining this connection in younger adults has mainly focused on women. For the current study, researchers examined data on 615 men who had a stroke before age 50 and compared their smoking habits to a control group of 530 similar men who didn’t have a history of stroke.
Overall, current smokers were 88 per cent more likely to have a stroke than men who never smoked, the study found.
Light smokers who had fewer than 11 cigarettes a day were 46 per cent more likely to have a stroke. Heavy smokers with a two pack-a-day habit, or more, were over five times more likely to have a stroke.
“The simple takeaway is the more you smoke, the more you stroke,” said lead study author Janina Markidan of the University of Maryland School of Medicine in Baltimore.
Smoking causes inflammation in blood vessels that increases the risk of blood clots forming, which in turn increases the risk of stroke, Markidan said by email.
“Although reducing the number of cigarettes smoked can reduce your risk of stroke, quitting is still the best choice for smokers,” Markidan added.
For the study, researchers focused on what’s known as an ischemic stroke, the most common kind, which occurs when a clot blocks an artery carrying blood to the brain.
Among the stroke cases included in the study, 239 men had never smoked and 108 were former smokers. Another 103 men smoked less than 11 cigarettes daily, while 97 men smoked between 11 and 20 cigarettes a day and 40 men smoked 21 to 39 cigarettes daily.
An additional 28 men who had strokes smoked more than 40 cigarettes, or two packs, a day.
Most of the men who had strokes in the study were between 35 and 49 years old.
The study wasn’t a controlled experiment designed to prove whether or how smoking habits might directly influence the potential for a stroke in younger men.
Another limitation is that researchers lacked data on other tobacco products participants used in addition to cigarettes, which might influence their risk of stroke, researchers note in the journal Stroke.
The study team also lacked data on other factors that can independently influence the risk of stroke such as alcohol consumption or exercise habits.
Even so, the results suggest the link between smoking and strokes that is well established for older adults also holds true for younger smokers, said Allan Hackshaw, a researcher at University College London in the UK, who wasn’t involved in the study.
“It shows that smoking has a serious impact even when people are younger,” Hackshaw said, adding, “Treatments for stroke are much better now (fewer die from it straight away), many people who suffer one can have long-lasting consequences and physical disabilities at an age when they are usually expected to be working and physically active/fit.”