New research from the American Heart Association shows that even light smoking can cause serious harm to the heart and raise the risk of early death.
The study found that smoking only a few cigarettes a day still leads to major health damage, disproving the idea that smoking less makes it safe. Scientists analyzed data from 22 long-term health studies that followed more than 320,000 adults over two decades.
The study was published in PLOS Medicine and is one of the largest investigations ever done on low-level smoking and cardiovascular health. Researchers divided participants into three categories: never smokers, current smokers and former smokers. They then tracked smoking habits, total smoking history and how long it had been since former smokers quit.
The results showed that people who currently smoke just two to five cigarettes a day were more than twice as likely to develop any form of heart disease when compared to people who never smoked. Light smokers also had a 60 percent higher risk of dying from any cause. Researchers documented more than 125,000 deaths and 54,000 cardiovascular events in the combined datasets.
Study author Michael J. Blaha said the scale of the project allowed scientists to see patterns that smaller studies could not. He noted that the rise in low-intensity smoking makes it important to understand the real risks.
According to the team, smoking even one cigarette a day was linked to higher risks for most major heart problems.
The study also showed that quitting smoking brings immediate health benefits. The risk of heart attack, stroke and heart failure begins to drop quickly after a person stops smoking. In the first ten years, people who quit saw major improvements in their overall health. However, the research found that it may take thirty years or more for a former smoker’s risk levels to reach those of someone who never smoked.
For example, people who had been smoke-free for about twenty years had more than an 80 percent lower risk of death than current smokers. Even so, the researchers warned that the damage caused by smoking fades slowly and that some elevated risk can remain for decades.
The American Heart Association stated that the message of the study is simple.
There is no safe level of cigarette use. Light smoking still causes cardiovascular damage. They stressed that reducing cigarette consumption is not enough and that quitting entirely and quitting early in life are the actions that truly protect long-term health.
Researchers noted some limitations in the data, including the fact that participants reported their own smoking habits at the start of each study. Social pressure around smoking may have led some people to understate how much they smoked. The project also did not assess the use of e-cigarettes or other tobacco products.
Despite the limitations, scientists said the findings are clear. Light smokers face serious risks, and only full cessation can reverse the harm. The study provides new evidence that supports long-term warnings from health experts and adds weight to public health campaigns urging Americans to stop smoking completely.