- Researchers say that smoking as few as two cigarettes a day can significantly increase a person’s risk of heart disease.
- Experts say there is no safe level of smoking, and the best preventive strategy is to never start the unhealthy habit.
- They say quitting smoking can be a challenge, but medical aids such as nicotine patches, as well as support from friends, can help.
Even an occasional cigarette can endanger a person’s health and increase their risk of cardiovascular disease, according to a new study.
Researchers report that people who smoke as few as two cigarettes per day have a 57% higher risk of heart failure and a 60% higher risk of death from any cause.
They add that a person’s health risks decline significantly in the decade after quitting smoking. However, the researchers note that a former smoker can still have increased health risks three decades after giving up tobacco.
They say the main message from their research is for people to quit smoking as early as possible.
“Lower-intensity smoking is associated with cardiovascular risk and the primary public health message for current smokers should be early cessation, rather than reducing the amount of smoking,” the study authors wrote.
The researchers published their findings on November 18 in PLOS Medicine.
Experts not involved in the study say the research spotlights an important health issue facing the United States.
“This is a robust and important study,” said Kevin Shah, MD, a cardiologist and program director of Heart Failure Outreach at MemorialCare Heart & Vascular Institute at Long Beach Medical Center in California.
“It provides compelling evidence that cigarette smoking — even at low levels — substantially increases the risk of cardiovascular disease and premature death,” Shah told Healthline.
“These results highlight the tremendous continued negative impact that smoking has on public health,” added Cheng-Han Chen, MD, an interventional cardiologist and medical director of the Structural Heart Program at Saddleback Medical Center in Laguna Hills, CA.
To reach their findings, the researchers at Johns Hopkins University in Maryland analyzed data from more than 300,000 adults who participated in 22 longitudinal studies.
Some of the study participants were followed for almost 20 years.
During that time, the researchers documented 125,000 deaths and 54,000 cardiovascular events such as heart attacks, strokes, and heart failure.
The researchers defined “low-intensity smoking” as two to five cigarettes per day. They reported that this level of smoking was associated with a 57% higher risk of heart failure and a 60% higher risk of death from any cause when compared to people who have never smoked.
They noted that a person’s risk of cardiovascular events drops substantially in the first decade after quitting smoking and continues to decrease over time. However, they said that even after three decades, former smokers can still exhibit higher risk than people who have never smoked.
The researchers said they embarked on this study because of a trend of people smoking fewer cigarettes rather than quitting.
The American Lung Association reports that adult smoking in the United States decreased from about 42% in 1965 to 12% in 2022. That’s a decline of more than 70%.
However, the association states that the number of people smoking fewer than 15 cigarettes per day increased 85% during the same period.
“In recent years, there has been an increase in the number of people who still smoke, but smoke less,” said Michael Blaha, MD, MPH, a study author and a lead investigator for the American Heart Association’s Tobacco Center for Regulatory Science grant-funded research initiatives, in a
“As smoking patterns shift with more people smoking fewer cigarettes, it’s important to understand the cardiovascular risks of low-intensity smoking and the long-term benefits of quitting,” Blaha continued.
Experts say this message is important for occasional smokers to understand.
“This [study] reinforces the message that there is no safe level of smoking. Cutting down is not enough,” said Shah.
Jayne Morgan, MD, a cardiologist and vice president of medical affairs at Hello Heart who specializes in women’s health and cardiovascular research, said the first few cigarettes can in fact do the most damage.
“There is no safe level of smoking for the cardiovascular system and the risk is not linear. The first few cigarettes cause a disproportionately large amount of damage,” Morgan told Healthline.
“This is because cardiovascular risk from smoking is driven by platelet activation, endothelial dysfunction, and vasospasm, which occur even at very low exposure, i.e., just one to two cigarettes,” she explained.
Chen said this message is particularly important for younger people.
“Younger adults need to understand that no amount of smoking is safe and that even occasional smoking will greatly increase your risk of death or heart disease,” he told Healthline.
“The most important thing [young adults] can do for their health at that stage is to quit smoking,” Chen added.
The Centers for Disease Control and Prevention (CDC)
Besides affecting heart health, smoking can also cause other diseases and conditions. They include:
- more than 10 types of cancer
- lung disease
- COPD
- asthma
- type 2 diabetes
- eye-related diseases
The CDC notes that cigarette smoking and secondhand smoke exposure cause more than 480,000 deaths each year in the United States. This accounts for nearly one in five deaths.
“Cigarette smoking is well known to harm almost every part of the body,” said Chen. “This study makes it clear that even as ‘few’ as two cigarettes a day can significantly increase your risk of death or disease.”
The CDC
The agency notes that despite the decline in use, tobacco remains the leading cause of preventable disease and death in the United States.
In addition, there are groups where cigarette smoking is higher than the rest of the population. They include:
- people 45 years to 64 years old
- non-Hispanic American Indian or Alaska Native adults.
- people with disabilities.
- people with severe generalized anxiety disorder.
- people with severe depression
Adults 18 years to 24 years of age have the highest prevalence of e-cigarette use.
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The American Lung Association lists a number of effective ways to quit smoking. They include:
- focus on your motivation
- build up confidence in quitting
- stress management
- medications such as nicotine patches, gum, lozenges, and nasal spray
- don’t try to do it alone
Morgan said it’s also helpful for a person to set a “quit date,” identify their triggers for smoking, create a replacement plan, and clean up their home and work environments to remove any traces of cigarettes and other tobacco products.
Chen added that seeking outside professional help is also crucial.
“To help you quit smoking, you should talk to your doctor about medications that can reduce the craving for nicotine,” he said. “You can also talk to a therapist or counselor about behavioral strategies that can help.”
Shah said the most effective strategies usually combine behavioral support with medical aids such as nicotine gum.
He added that this is a tough road that people should realize may take a long time.
“What’s important to emphasize is that quitting often takes multiple attempts and relapse is not failure — it’s part of the journey toward success,” Shah said. “People who use a combination of approaches, tailored to their own needs, are the most likely to quit for good.”
There are a number of ways a person can help a family member or friend quit smoking. They include:
- being patient with a person trying to quit
- understanding their triggers for smoking
- coming up with distractions
- finding the appropriate level of encouragement
