Despite dangers inherent in smoking cigarettes, the pastime still remains a popular activity. New research findings detail how quitting the habit is associated with reduced mortality risk. Researchers are now working to understand the full health impact of smoking.

The clear message is: smoking cigarettes is a habit that is harmful to health.

A​ recent study published in JAMA found that quitting smoking is associated with reduced mortality risk. The sooner people stop, the more benefit they are likely to see, the researchers found. The study adds to a growing body of evidence about the impact of smoking and the benefits of quitting.

I​n 2020, the Centers for Disease Control and Prevention (CDC) estimated that 12.5 per cent of the United States population was currently smoking cigarettes. The CDC also notes that “Cigarette smoking is the leading cause of preventable death in the United States.”

Smoking causes damage to the body and increases people’s risk for many health problems. For example, smoking cigarettes is associated with an increased risk of lung cancer, stroke and heart disease. These risks are related to the damage smoking causes to blood vessels and the lungs.

Dr Mary Martinasek, associate professor in public health at the University of Tampa, and member of the American Association for Respiratory Care (AARC), who was not involved in the study, told Medical News Today, “Because smoking cigarettes has been studied for over five decades, we know a lot about the effects of the multitude of chemicals in cigarette smoke and the hazards associated with inhaling them.”

“In the United States, smoking causes 87 per cent of lung cancer deaths, 32 per cent of coronary heart disease deaths, and 79 per cent of all cases of chronic obstructive pulmonary disease (COPD),” Dr Mary Martinasek

Dr Pushan Jani, UTHealth pulmonologist affiliated with Memorial Hermann-Texas Medical Center, who was also not involved in the study, further noted, “Smoking harms almost every organ in the body. Most importantly, it causes one in every four deaths secondary to cardiovascular diseases (such as heart attacks, and stroke) [which equals to about 800,000 deaths per year].”

“It causes 160,000 deaths secondary to lung cancer every year. It causes a lung disease called COPD, which is prevalent in 16 million US adults and is the third biggest cause of death in the [US],” he added.

Research is ongoing about the health risks of smoking and the benefits of quitting. This prospective cohort study looked at smoking and smoking cessation and the associated mortality risks. Researchers used information available from the US National Health Interview Survey in their data collection.

The researchers specifically looked at how these risks differed based on race, ethnicity, and sex. They included over 500,000 US adults in their research. The researchers particularly noted smoking status: current smoker, former smoker or never smoker. They also looked at when people quit and for how many years they had quit smoking.

The main finding was that smoking was associated with a double or more mortality rate across all groups. However, quitting smoking was associated with reduced mortality risk. This reduction was particularly pronounced based on the age someone stopped.

The study authors note that “quitting smoking before age 45 years was associated with reductions of approximately 90 per cent of the excess mortality risk associated with continued smoking and quitting at ages 45 to 64 years was associated with reductions of approximately 66 per cent of this excess risk, irrespective of race and ethnicity.”

In other words, the sooner people quit, the better the results. Study author Dr Blake Thomson highlighted this critical takeaway from the study, “The key point is that smoking is extremely harmful to human health, but critically, quitting smoking really works. The younger smokers quit, and the more time accrues since they quit, the greater the health benefits.”

“As we observed in this study, those who quit before [age 35] avoided almost all of the excess mortality risk associated with continued smoking. The benefits of quitting, even at older ages, are tremendous. It’s never too late to quit, but the earlier, the better,” Dr Blake Thomson said.

This study included many participants, adding to a diverse and large amount of data collection. However, it did have limitations that are important to take into account.

First, the data on smoking habits was self-reported and from a single point in time, so it doesn’t account for components like people who quit later or who started smoking. The researchers divided participants into four main racial groups. Still, they note that there were likely many differences within these four groups.

They also noted that the people who quit may have been more likely to have a disease or be at an increased risk for death. Therefore, the data may actually underestimate how quitting smoking can help those who are currently healthy.

Finally, there is the risk of confounding, and researchers did not look at geographically-related factors.

Regardless, the study adds to evidence for the health benefits of quitting smoking. Dr Thomson noted to MNT that even if people fail at quitting, they should strive to try again.

“These findings are important for both those who currently smoke cigarettes and for those who formerly smoked cigarettes. For current smokers, it is essential to take quitting seriously. Even after relapses, keep trying. It is always worth encouraging another attempt and highlighting its benefits,” Dr Thomson said.

“For former smokers and their healthcare providers, the message is to continue to celebrate that achievement and work to keep it a permanent change. This is important for both individuals who smoke and for their healthcare team to understand,” he added.

Dr Martinasek also reiterated that many resources were available in the US to help people who are ready to quit smoking, “Many states offer free quit programmes and free resources to quit smoking. Reaching out to a respiratory therapist [RT] can be a good first start. RTs work in local hospitals and healthcare facilities and have the knowledge to assist with quitting smoking.”

Dr Martinasek recommended smokefree.gov as well as US states’ own websites and free resources to help support people who are thinking of quitting smoking.

“There are also free apps that can assist with quitting smoking and provide group support. The only products that are approved for quitting are prescribed medications and over-the-counter nicotine replacement therapies. These, coupled with quit coach counselling, can be effective methods for quitting,” she added.

• A Medical News Today report