Even Low-Intensity Smoking Increases Risk for Cardiovascular Disease, Death

THURSDAY, Nov. 20, 2025 (HealthDay News) — Even occasional or low-intensity smoking significantly increases cardiovascular and mortality risks, according to a study published online Nov. 18 in PLOS Medicine.

Erfan Tasdighi, M.D., from the Johns Hopkins Ciccarone Center for Prevention of Cardiovascular Disease in Baltimore, and colleagues examined the relationships among smoking burden, intensity, and cessation duration across multiple cardiovascular outcomes. The analysis included data from 323,826 adult participants in 22 prospective cohort studies with median follow-up varying from 14.4 to 19.9 years.

The researchers found that compared with never-smokers, participants with two to five cigarettes per day (CPD) showed substantially elevated cardiovascular risks, including for atrial fibrillation (hazard ratio [HR], 1.26) and heart failure (HR, 1.57) and for increased cardiovascular disease (CVD) mortality (HR, 1.57) and all-cause mortality (HR, 1.60). Risk was even higher for smoking 11 to 15 CPD (CVD: HR, 1.87) and all-cause mortality (HR, 2.30). Even steeper risk was seen for the initial 20 pack-years and 20 CPD. The first 10 years after smoking cessation were associated with the most substantial reduction in risk across all outcomes, although the progressive risk reduction continued over extended time periods. Former smokers showed 80 percent lower relative risk versus current smokers within 20 years of cessation.

“It is remarkable how harmful smoking is — even low doses of smoking confer large cardiovascular risks,” the authors said in a statement. “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.”

Abstract/Full Text