For a long time, some smokers believed that very moderate tobacco consumption, between one to four cigarettes per day, limited the risks. But a new scientific study shows that this is actually a preconceived idea.
A risk of dying prematurely increased by 60%
A team from Johns Hopkins University has just published the conclusions of a meta-analysis, bringing together data from more than 300,000 people followed for nearly 20 years. During that time, they documented more than 125,000 deaths and 54,000 cardiovascular events, such as heart attacks, strokes and heart failure.
Their findings are clear: even very low-intensity smoking, defined as two to five cigarettes per day, was associated with a risk of heart failure increased by 50% and death increased by 60%compared to non-smokers. From 11 to 15 cigarettes, the risk of death is more than doubled.
The team of Dr. Marc Blaha, professor of cardiology and epidemiology and director of clinical research at the Johns Hopkins Ciccarone Center for the Prevention of Cardiovascular Disease, in Baltimore, thus recalls an essential point.
“No level of smoking is without risk. It is remarkable how harmful smoking is, and even small doses carry great risks. It is imperative to quit smoking as early as possible in life. The time elapsed since complete cessation (stopping smoking) is more important than a smaller quantity of cigarettes each day.”
Even “light smoking” causes serious damage to the heart
Our expert, tobacco specialist Olivier Galera, confirms the dangerousness of these low doses.
“This study shows that a little smoking has a significant impact on health, just one cigarette per day already increases the risk of myocardial infarction by 48% in men and 57% in women. And this is due to the carbon monoxide (CO) present in the smoke. So if we want to put it simply, a person who smokes one cigarette per day has a greater risk of having a myocardial infarction than a person with cholesterol.”
Smoking makes you breathe more polluted air than at peak pollution
To objectify this risk, Dr. Galera uses a tool commonly found in consultations: measuring exhaled carbon monoxide.
“In consultation, we have a measuring device that allows us to measure the quantity of CO in the lungs. This gas is a toxic element for the heart, which can be compared to air pollution. As a reminder, the alert threshold is 8.5 ppm. However, for a person who smokes between one to 4 cigarettes per day, these results are between 11 and 14 ppm. This means that this person breathes more polluted air than when we exceed the pollution alert threshold And this is understandable since smoking actively causes smoke concentrated in carbon monoxide directly into the lungs.
In other words, even a “very light” smoker inhales a daily level of toxicity above the environmental alert threshold.
Why just one cigarette can already lead to strong addiction
Furthermore, and contrary to popular belief, addiction is not proportional to the number of cigarettes. “Even one cigarette a day causes addiction. Because tobacco addiction is not linked to the quantity of cigarettes smoked. You can pull hard and smoke quickly, and therefore have a higher concentration of nicotine in the body – and be more dependent on it. And generally, it’s these people who smoke quickly and draw hard on their cigarettes who are very addicted.” specifies our expert.
“On the contrary, we can smoke more cigarettes, and puff less, by smoking more slowly. In this case, we will have less nicotine in the body, even with more cigarettes smoked. So, for tobacco, we are not using a comparison of quantity to estimate dependence.”
This dimension explains why some “small smokers” struggle just as much – or even more – to quit.
Reducing is not enough: only complete shutdowns reduce the risks
Because it is the definitive judgment that is crucial. Indeed, the study recalls that even 20 years after stopping, former smokers still have a higher cardiovascular risk than those who have never smoked.
“The risk of cardiovascular events declined most in the first decade after quitting smoking and continued to decline over time. However, even up to three decades later, former smokers may still be at higher risk than those who have never smoked.” note the researchers. This should not discourage quitting smoking, but rather encourage quitting early.
Dr. Galera emphasizes this essential point. “A person is always advised to stop smoking completely rather than reduce their consumption, since cutting back will not be a way to reduce risks. A person who stops smoking completely, their cardiovascular risks will decrease quickly, because they are linked to carbon monoxide“.
Concerning cancers, the reduction is slower. “The risk of cancer will also decrease over time after stopping smoking. But more slowly. It is estimated at a 39% decrease every 5 years. But tars persist for a long time in the body, it is complicated to get rid of them. So we believe that monitoring must continue for ex-smokers because they can still develop kidney, lung or bladder cancer, sometimes 15 to 25 years after stopping smoking.
1. How do I know if I am already addicted to just one cigarette a day?
Addiction can happen quickly. Observe your morning craving. Also note your difficulty in delaying the first cigarette. Monitor the pleasure felt despite a small quantity. The Fagerström test can help. A single cigarette is sometimes enough to establish a lasting nicotine reflex.
2. What should I do if I smoke little but my CO levels are high?
CO rises quickly even with few cigarettes. Ask for a measurement at the pharmacy. Limit closed environments. Drink plenty of water to improve CO elimination. In case of high levels, consult a tobacco specialist. But only complete cessation remains the only truly effective solution for normalizing CO.
3. How to maximize the reduction in cardiovascular risk after stopping?
Stop suddenly if possible. Move every day to stimulate circulation. Monitor your blood pressure regularly. Eat a diet rich in fiber. Medical follow-up helps monitor progress. The cardiovascular benefits begin quickly, especially in the first weeks without tobacco.