• Posted August 17, 2026

Many Smokers Unaware Of Heart, Brain Risks Of Smoking

Many smokers still haven’t absorbed the fact that smoking and secondhand smoke cause heart attacks and strokes, despite decades of messaging around tobacco’s health risks, a new study says.

More than 90% know that smoking causes lung cancer, but fewer know about its links to other fatal conditions, researchers report in the journal BMJ Open.

Only about 80% knew smoking contributes to heart disease and heart attacks, and 70% are aware it causes strokes, researchers found.

In fact, across two decades they found almost no progress in knowledge of the health risks associated with smoking.

“Knowledge gaps about the major health effects of smoking and secondhand smoke are deeply concerning,” said lead researcher Janet Chung-Hall, a research scientist for the International Tobacco Control Policy Evaluation Project at the University of Waterloo in Canada.

“The low awareness of the cardiovascular harms of smoking and secondhand smoke is particularly troubling given that smoking causes more than 2 million cardiovascular deaths worldwide each year,” she said in a news release. “Increasing public awareness of these risks should be a greater public health priority.”

For the new study, researchers analyzed data from more than 240,000 adult smokers across 46 countries.

Results showed that knowledge of the risks of secondhand smoke actually decreased in the majority of high-income countries studied, including Canada, the United States, New Zealand, England and Japan.

And even though about 90% knew that smoking causes lung cancer, fewer (77%) knew that secondhand smoke does as well, researchers found.

“Knowledge is an important first step toward quitting smoking and protecting others from secondhand smoke,” researcher Geoffrey Fong, a professor of psychology and public health sciences at the University of Waterloo, said in a news release.

“Our findings highlight the need for governments to implement stronger, sustained public education about the cardiovascular as well as cancer risks of smoking and secondhand smoke,” Fong said. 

“Policies such as large pictorial warnings and sustained media campaigns can increase awareness, encouraging quitting among those who smoke and discouraging young people from starting to smoke.” he added.

More information

The U.S. Centers for Disease Control and Prevention has more on the health harms of smoking.

SOURCES: University of Waterloo, news release, Aug. 13, 2026; BMJ Open, Aug. 13, 2026