Study: Passive smoking doubles stroke risk

A recent study published in eClinicalMedicine has explored the complex link between smoking habits and the risk of having a stroke, uncovering how different smoking behaviors affect stroke likelihood.

The research found a markedly higher risk of stroke among current smokers compared to non-smokers, especially for ischaemic strokes caused by blockages in blood flow to the brain. This global research effort included contributions from St John’s Medical College and Research Institute in Bengaluru.

The study identified that smoking both filtered and non-filtered cigarettes increased the risk of stroke. Being exposed to second-hand smoke for over 10 hours a week also significantly raised the chance of experiencing a stroke, including ischaemic and intracerebral haemorrhage (ICH) strokes, the latter resulting from a blood vessel bursting within the brain.

Particularly alarming was the discovery that heavy smokers under the age of 50 (those who smoked more than 20 cigarettes a day) had their stroke risk more than double, a risk increase even greater than that seen in individuals over 70. For smokers aged 50-59, the likelihood of suffering a stroke in one of the brain’s major blood vessels surged eightfold.

Upon analyzing data from 32 countries across different economic statuses, the study observed variations in stroke risk among current smokers based on region, with the highest risks in Western Europe and North America. It was noted that high-income countries (HICs) saw a greater risk compared to low- and middle-income countries (LMICs), and younger smokers were at a higher risk than older ones. The danger of stroke also rose with the number of cigarettes smoked daily, particularly in HICs.

These findings highlight the urgent need for worldwide efforts to reduce tobacco use and exposure. The study suggests focusing on preventing young people from starting to smoke and supporting current smokers in quitting. It also recommends policies to create and enforce smoke-free spaces.

The study also pointed out significant regional differences in smoking rates, with nearly half of the young male population in South East Asia and over 16% of young females in Eastern/Central Europe and the Middle East reported as smokers, emphasizing the varied impact of smoking on stroke risk across different populations.