Overview
- Analyzing more than 300,000 adults across 22 long-term cohorts, researchers linked smoking 2–5 cigarettes daily to a 50% higher risk of cardiovascular disease and a 60% higher risk of death versus never smoking.
- Risk fell most in the first decade after quitting, yet former smokers often remained at higher risk for decades, with estimates of roughly 31–40 years to approach never-smoker levels.
- Even smoking one or fewer cigarettes per day was associated with elevated risks for most heart outcomes and causes of death studied, with exceptions reported for stroke and atrial fibrillation at that very low level.
- The findings, published in PLOS Medicine, indicate that cutting down does not eliminate harm and support counseling that prioritizes quitting completely as early as possible.
- The cross-cohort effort documented more than 125,000 deaths and 54,000 cardiovascular events and noted limitations, including limited tracking of changes in smoking behavior and sparse detail on other tobacco products or cause-specific mortality.