Smoking Linked to Tripled Risk of Fatal Brain Bleeding, Study Finds

Smoking could triple the risk of fatal bleeding on the brain, according to a study.

The researchers looked at data on 16,282 pairs of twins born before 1958, collected over the course of 42 years up until 2018. They noted which participants died of a type of stroke called subarachnoid hemorrhage (SAH). This is where bleeding occurs in the space surrounding the brain.

The team also also looked at lifestyle information including how often the participants smoked. The volunteers were grouped as current light smokers, at less than 10 cigarettes per day, moderate at between 10 to 19, and heavy at over 20. Using a national database, they were able to record how many participants died by December 31, 2018.

By the end of the study, 120 participants had died of SAH. Of those, two pairs of twins both died of SAH, while one twin died of the condition in the remaining 116 cases.

Smoking heavily or moderately carried a 3 times greater risk of dying from SAH, while the risk was 2.8 times higher for light smokers when compared with non smokers and former smokers.

Co-author Ilari Rautalin, a medical and Ph.D. student at the University of Helsinki in Finland, told Newsweek: "To date, this is the strongest evidence about the cause and effect relationships between smoking and SAH."

Jaakko Kaprio, professor of genetic epidemiology at the University of Helsinki who co-authored the paper, told Newsweek a major limitation of the study was the team did not have data on SAH cases that were not deadly.

"However, as smoking also increases the risk for non-fatal SAHs, we think it is extremely unlikely that this could impact substantially in our findings and conclusions," he said.

Co-author Miikka Korja, an associate professor and cerebrovascular neurosurgeon at Helsinki University Hospital, told Newsweek "our findings suggest that smoking causes a significant share of subarachnoid haemorrhages in both men and women, it markedly highlights the previously known adverse effects of smoking associated with many other diseases."

Davinia Green, head of prevention at the U.K.-based charity Stroke Association who was not involved in the study, told Newsweek the study "adds to evidence that smoking increases the risk of fatal bleed in the brain. But this analysis doesn't take into account other things that might have increased a person's risk of a fatal bleed in the brain, such as high blood pressure."

She said: "Most strokes are caused by environmental factors, not genetic factors. This is both positive and empowering as it means people can take action to reduce their risk of stroke."

According to the U.S Centers for Disease Control and Prevention, 34.2 million people in the U.S. smoke, or 13.7 percent of all adults.

smoking, cigarette, stock, getty
A stock image shows a person putting out a cigarette. A study has linked smoking to bleeding in the brain.