Everyone knows smoking isn’t good for you. Smokers often develop chronic coughs and shortness of breath. Over time, smoking can also lead to a variety of serious health conditions including COPD, emphysema and lung cancer.
“Smoking is a very slow killer,” says Amanda Holm, MPH, who manages the Tobacco Treatment Service at Henry Ford Health. “Over time, the unhealthy effects of smoking settle in and it’s a hard road back.”
Quitting smoking is one of the best things you can do for your overall health and the health of your immune system. “Within just a few months of stopping smoking, many of your body’s important functions begin to recover,” says Holm. “Your heart rate and blood pressure start to decrease, your lung function improves and your risk of heart attack drops.”
It can take a little longer for your immune system to fully bounce back, so the sooner you quit smoking, the better.
Impact Of Smoking On Your Immune System
“If your immune system is Superman, then smoking is its kryptonite,” says Holm. Many of the components of tobacco smoke impair the body’s ability to fight off bacterial and viral infections. That can leave you vulnerable to all kinds of illnesses.
Smokers are more likely than nonsmokers to get respiratory infections—including cold, flu and COVID-19. One study found that smokers are twice as likely as nonsmokers to get colds. Smoking can also reduce the effectiveness of vaccines designed to protect against infections like flu and COVID-19—further increasing the risk and severity of those illnesses in smokers.
How Long After Quitting Smoking Does Your Immune System Recover?
Tobacco Treatment Service At Henry Ford
The good news is that certain aspects of your immune system have the power to bounce back very quickly after you smoke your last cigarette. In particular, it’s the innate immune system that recovers first and fastest.
“The innate immune system is the body’s first line of defense,” says Holm. “It’s the fast-acting response that helps keep pathogens from invading the body.”
Smoking impairs this response by lowering the production of cytokines, molecules that help control inflammation. But a recent study found that, after quitting smoking, a person’s cytokine levels quickly returned to levels similar to nonsmokers.
The Long-Term Effects Of Smoking On The Immune System
The bad news is that the adaptive immune system can take years to recover after you quit smoking. The adaptive immune system is the slower-acting one—the part of your immune system that remembers threats and can respond when exposed to them again.
“The adaptive immune system is important for mounting a response to a vaccine or a repeated threat like cold germs or COVID-19,” says Holm. “When you smoke, you blunt that response.”
And because adaptive immunity relies on long-term changes to DNA, it also takes much longer to repair itself once you stop smoking. “It may take years to recover, and the longer and more you smoked, the less efficient the recovery process,” says Holm. “You’ll continue to see improvements, but some damage may not be able to be undone.”
Ways To Help Boost Your Immunity
Whether you’re still smoking or quit years ago, it’s worth taking some extra steps to increase the strength of your immune system. “A healthy, mostly plant-based diet is a great place to start,” says Holm. “Eating a diet that’s full of fruits, leafy greens and other vegetables helps you get the nutrients you need to keep your immune system fortified.”
Antioxidant vitamins like vitamins A, C and E are particularly important for immunity. And smoking reduces the levels of antioxidants in the blood. Smokers and former smokers should make sure their diets include plenty of foods that provide these immune-boosting vitamins. Leafy greens, citrus fruits, red and yellow vegetables, and nuts are good antioxidant-rich additions to your diet.
Getting regular exercise—even just a 30-minute walk every day—is another way to give your immune system a boost. And since your body can’t effectively fight off invaders when you’re run down, it’s also important to focus on getting enough restorative sleep every night.
If You’re Ready To Quit Smoking, Get Help
If you’re still smoking and have decided it’s time to quit, congratulations. You’re about to make the smartest possible decision for your health. But going cold turkey—or going it alone—isn’t the best way to go about quitting.
“Research has shown that the most effective way to quit smoking is a combination of behavioral counseling and nicotine replacement with a patch, gum, lozenge or medication,” says Holm. She also recommends setting a quit date that gives you time to prepare—one or two weeks to talk to friends and loved ones, plan some strategies for tough times and get the medications you prefer.
“If you’re ready to quit, reach out and find the help and support you need,” says Holm. “That’s what will lead to success.”
Reviewed by Amanda Holm, MPH, project manager for the Tobacco Treatment Service in the Henry Ford Center for Health Promotion and Disease Prevention.
