The benefits of quitting are significant, especially in the first decade, but some excess risk remains for decades. Cutting back helps far less than quitting fully.

Low-Intensity Smoking Still Raises Major Cardiovascular Risks
An extensive review of nearly two dozen long-term studies shows that people who smoke only a small number of cigarettes still face a much higher likelihood of heart disease and early death compared to those who have never smoked. This elevated risk persists long after quitting. Michael Blaha of the Johns Hopkins Ciccarone Center for Prevention of Cardiovascular Disease, USA, and his colleagues published these results today (November 18th) in the open-access journal PLOS Medicine.

Scientists have long known that smoking contributes to cardiovascular disease, but the connection between the number of cigarettes someone smokes and their specific level of risk has been less clear, particularly for people who smoke lightly. As smoking habits shift and more individuals consume fewer cigarettes than in the past, gaining a clearer understanding of their long-term heart risks and the benefits of quitting remains essential, even for those who do not come close to a pack a day.

Large Multi-Study Analysis Tracks Smoking’s Long-Term Impact
Blaha’s research team examined health data from more than 300,000 participants across 22 longitudinal studies (which follow people over extended periods) for as long as 19.9 years. During that time, the studies recorded over 125,000 deaths and 54,000 cardiovascular events, including heart attacks, strokes, and heart failure.

Their analysis found that smoking as few as two to five cigarettes per day was linked to a 50 percent higher risk of heart failure and a 60 percent higher risk of death from any cause compared with never smoking. The chance of experiencing a cardiovascular event decreased most noticeably in the first 10 years after quitting and continued to decline the longer someone remained smoke-free. Even so, former smokers still showed higher risks than people who never smoked, sometimes lasting up to 30 years after quitting.