Even smoking just a few cigarettes daily significantly heightens the risk of heart failure and early death, according to a major review of long-term studies. The research, involving over 300,000 adults, shows that benefits from quitting emerge quickly but persist for up to three decades. Experts urge complete cessation, especially early in life, for optimal protection.
A comprehensive analysis published on November 18 in PLOS Medicine reveals the enduring cardiovascular dangers of light smoking. Led by Michael Blaha from the Johns Hopkins Ciccarone Center for Prevention of Cardiovascular Disease, the study drew from 22 longitudinal cohorts tracking more than 300,000 adults for up to 19.9 years. During this period, researchers documented over 125,000 deaths and 54,000 cardiovascular events, such as heart attacks, strokes, and heart failure.
The findings indicate that individuals smoking two to five cigarettes per day face a 50 percent increased risk of heart failure and a 60 percent higher risk of death from any cause compared to never-smokers. While quitting substantially lowers these risks—with the most significant drops in the first 10 years—former smokers retain elevated risks relative to lifelong non-smokers for as long as three decades.
"This is one of the largest studies of cigarette smoking to date using the highest quality data in the cardiovascular epidemiology literature," the authors stated. "It is remarkable how harmful smoking is—even low doses of smoking confer large cardiovascular risks. As far as behavior change, it is imperative to quit smoking as early in life as possible, as the amount of time passed since complete cessation from cigarettes is more important [than] prolonged exposure to a lower quantity of cigarettes each day."
The research underscores that reducing cigarette intake alone does not match the protective effects of total abstinence, reinforcing public health calls for early and complete quitting to mitigate long-term harm.