Smoking & Heart Disease: The Hidden Cardiovascular Risks Smokers Ignore

According to an international study published in BMJ Open in 2026, two decades of global tobacco control efforts have failed to ensure smokers fully understand that smoking and second-hand smoke cause heart attacks and strokes. Researchers analyzed data from more than 240,000 adult smokers across 46 countries between 2002 and 2022, revealing a persistent knowledge gap regarding cardiovascular risks.

Global Tobacco Control Data Reveals Persistent Knowledge Gaps Across 46 Countries

Led by the University of Waterloo and the Global Tobacco Control Program at the U.S. Centers for Disease Control and Prevention (CDC), the research represents the largest investigation of its kind into public awareness of tobacco harms. The findings show that while more than 90 per cent of surveyed adults who smoke know that the habit causes lung cancer, only about 80 per cent understand it triggers heart disease or heart attacks. Furthermore, just 70 per cent recognize that smoking causes strokes.

The situation appears even starker regarding passive exposure. In several high-income nations—including Australia, Germany, England, the U.S., New Zealand, and Canada—fewer than half of adults who smoke realize that second-hand smoke causes heart disease or heart attacks. Meanwhile, China and its estimated 300 million smokers rank among the regions with the lowest overall awareness.

Cardiovascular Risks and the Two-Decade Stagnation in Public Health Awareness

Tobacco use remains the leading preventable cause of disease and death worldwide, with up to two-thirds of lifelong smokers dying from a smoking-caused illness and losing over a decade of life on average, according to the research data.

The low awareness of the cardiovascular harms of smoking and second-hand smoke is particularly troubling given that smoking causes more than 2 million cardiovascular deaths worldwide each year. Increasing public awareness of these risks should be a greater public health priority.

Across the two decades analyzed in the research, researchers observed almost no progress in global knowledge concerning these health risks. Although nations like Bangladesh, India, Thailand, and Vietnam saw improvements in cardiovascular risk awareness, the majority of high-income countries—including Canada, the U.S., New Zealand, England, and Japan—actually experienced a decline in awareness regarding the dangers of second-hand smoke.

Implementing WHO Framework Policies to Drive Smoking Cessation

To combat these enduring deficits, public health advocates point to established international guidelines. Governments can utilize policies outlined in the World Health Organization Framework Convention on Tobacco Control, a treaty signed by more than 180 countries.

Knowledge is an important first step toward quitting smoking and protecting others from second-hand smoke, said Dr. Geoffrey T. Fong, Principal Investigator of the ITC Project and University Professor of Psychology and Public Health Sciences at Waterloo. Our findings highlight the need for governments to implement stronger, sustained public education about the cardiovascular as well as cancer risks of smoking and second-hand smoke. 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.