Daijiworld Media Network – New Delhi
New Delhi, Nov 20: A major new medical analysis has delivered a stark warning to “light” or occasional smokers: even two to five cigarettes a day can sharply increase the risk of heart failure and premature death. The large-scale study, published in PLOS Medicine, examined data from more than 3.2 lakh adults over nearly two decades and revealed that low-intensity smoking is far from harmless.
The research team, led by Dr Michael Blaha of Johns Hopkins University, pooled information from 22 long-running cohort studies spanning different regions. The combined dataset of 323,826 adults, followed for up to 19.9 years, offered one of the clearest pictures yet of how even minimal smoking affects long-term health. By analysing smoking behaviour, health outcomes, and cardiovascular events, the investigators were able to estimate risk levels for people who smoke just a few cigarettes daily — a group often dismissed as low-risk.
The findings paint a sobering picture. Smokers who consumed only 2–5 cigarettes per day faced nearly a 60 per cent higher risk of death from any cause compared to those who never smoked. Their risk of developing heart failure was also significantly elevated, with hazard ratios pointing to roughly a 50–60 per cent increase. Researchers noted that the steepest climb in risk occurred at the very lowest end of cigarette consumption, underscoring that the jump from zero to a couple of cigarettes is more damaging proportionally than increases at higher levels.
Heart failure, a progressive condition in which the heart’s ability to pump blood weakens over time, remains one of the world’s leading causes of disability and death. Tobacco smoke accelerates vessel damage, inflammation, plaque buildup and clotting, while nicotine disrupts rhythm and pumping efficiency — effects that begin even with limited exposure. According to the study’s analysis, the notion that “social smoking” is harmless stands firmly contradicted by evidence.
The report also delivers crucial insights on quitting. While cutting down offers little protection, giving up smoking entirely reduces risk relatively quickly. The largest drop occurs in the first decade after quitting, with continued gradual improvement over the years. However, the researchers caution that former smokers may still carry a slightly elevated heart failure risk for decades, with some estimates suggesting it can take more than 30 years for their risk profile to resemble that of a lifelong non-smoker.
Medical experts say the message is unmistakable: there is no safe level of smoking. The popular belief that one or two cigarettes a day fall within harmless limits does not hold up under scientific scrutiny. The latest evidence stresses that complete cessation — not reduction — is the only reliable path to lowering long-term risk.
As the study underscores, even occasional smoking comes with significant consequences. For anyone who lights up “once in a while” or limits themselves to just a couple of cigarettes a day, the warning is clear: the heart still pays the price, and quitting entirely remains the best protection.