Tobacco use is the leading cause of preventable death in the United States. According to the Centers for Disease Control and Prevention (CDC), close to a half a million Americans die prematurely each year due to smoking or exposure to secondhand smoke.

In addition to increasing your risk for heart disease, stroke, cancer, lung disease, and many other health conditions, smoking also has a negative impact on your brain.

In this article, we’ll take a closer look at the effects of smoking on your brain as well as the benefits of quitting.

Most people understand how smoking affects the lungs and heart, but what’s less known is the impact that nicotine has on the brain.

“Nicotine mimics several neurotransmitters, [which send signals] in the brain. [Since nicotine is] similar in shape to the neurotransmitter acetylcholine, signaling increases in the brain,” explains Lori A. Russell-Chapin, PhD, professor at Bradley University’s Online Masters of Counseling Program.

Nicotine also activates dopamine signals, creating a pleasurable sensation.

Over time, the brain begins to compensate for the increased signaling activity by reducing the number of acetylcholine receptors, she explains. This causes a nicotine tolerance, so continued and more nicotine is needed.

Nicotine also stimulates the pleasure centers of the brain, mimicking dopamine, so your brain starts to associate nicotine use with feeling good.

According to the National Institutes of Health, the nicotine in cigarettes changes your brain, which leads to withdrawal symptoms when you try to quit. When this happens, you may experience a variety of side effects including anxiety, irritability, and a strong craving for nicotine.

Unfortunately, when these symptoms strike, many people reach for another cigarette to ease the effects of withdrawal.

The changes that occur in the brain as a result of this cycle creates a dependence on nicotine because your body is used to having the nicotine in your system, which then becomes an addiction that can be difficult to break.

While the effects of nicotine may take a while to notice, adverse side effects related to the heart and lungs are likely the first ones a smoker will notice.

Here are the most common side effects of nicotine and smoking on the brain.

Cognitive decline typically happens naturally as you get older. You may become more forgetful or not be able to think as quickly as you did when you were younger. But if you smoke, you may experience faster cognitive decline than nonsmokers.

This is even more serious for men, according to a 2012 study that examined the cognitive data of more than 7,000 men and women over a 12-year period. The researchers found that middle-aged male smokers experienced more rapid cognitive decline than nonsmokers or female smokers.

Smokers also have an increased risk of dementia, a condition that can affect memory, thinking abilities, language skills, judgement, and behavior. It may also cause personality changes.

A 2015 research review looked at 37 studies comparing smokers and nonsmokers and found that smokers were 30 percent more likely to develop dementia. The review also found that quitting smoking decreases the risk of dementia to that of a nonsmoker.

According to a 2017 study, the longer you smoke, the higher your risk of greater age-related brain volume loss.

Researchers found that smoking negatively affected the structural integrity of subcortical brain regions. They also found that smokers, compared to nonsmokers, had greater amounts of age-related brain volume loss in several areas of the brain.

Smokers are more likely to suffer from a stroke than nonsmokers. According to the CDC, smoking increases the risk of a stroke by two to four times in both men and women. This risk increases if you smoke a higher number of cigarettes.

The good news is that within 5 years of quitting, your risk may decrease to that of a nonsmoker.

Smoking introduces many toxic chemicals into the brain and body, some of which have the ability to cause cancer.

Dr. Harshal Kirane, the medical director of Wellbridge Addiction Treatment and Research, explained that with repeated exposure to tobacco, genetic changes in the lungs, throat, or brain may increase your risk of developing cancer.

Although research on e-cigarettes is limited, we know so far that they can have a negative impact on your brain and overall health.

The National Institute on Drug Abuse reports that e-cigarettes that contain nicotine produce similar changes in the brain as cigarettes. What researchers have yet to determine, though, is if e-cigarettes can cause addiction in the same way as cigarettes.

Quitting nicotine can benefit your brain, as well as many other parts of your body.

A 2018 study found that smokers who quit for a prolonged period benefited from a reduced risk of dementia. Another study found that quitting tobacco can create positive structural changes to the brain’s cortex — though it can be a long process.

Mayo Clinic reports that once you stop entirely, the number of nicotine receptors in your brain will return to normal, and cravings should subside.

In addition to the positive changes to your brain health, quitting smoking can also benefit the rest of your body in many ways. According to Mayo Clinic, quitting tobacco can:

  • slow your heart rate just 20 minutes after your last cigarette
  • reduce the levels of carbon monoxide in your blood to a normal range within 12 hours
  • improve your circulation and lung function within 3 months
  • cut your risk of a heart attack by 50 percent within a year
  • reduce your stroke risk to that of a nonsmoker within 5 to 15 years

Quitting smoking can be tough, but it’s possible. That said, there are steps you can take to help stay nicotine-free for life.

  • Talk to your doctor. Russell-Chapin says the first step is to consult with a healthcare provider, as quitting smoking often produces a variety of withdrawal symptoms. Your doctor can work with you to create a solid plan that includes ways to deal with cravings and symptoms.
  • Nicotine replacement therapies. There are a variety of medications and nicotine replacement therapies that can assist with quitting. Some over-the-counter products include nicotine gum, patches, and lozenges. If you need more support, your doctor may recommend a prescription for a nicotine inhaler, nicotine nasal spray, or medication that helps block the effects of nicotine in the brain.
  • Counseling support. Individual or group counseling can help you get support for dealing with cravings and withdrawal symptoms. It can also help when you know other people are dealing with the same challenges as you.
  • Learn relaxation techniques. Being able to relax and deal with stress may help you get through the challenges of quitting. Some helpful techniques include diaphragmatic breathing, meditation, and progressive muscle relaxation.
  • Lifestyle modifications. Regular exercise, quality sleep, time with friends and family, and engaging in hobbies can help keep you on track with your quit goals.

Smoking is the leading preventable cause of death in the United States. Additionally, it’s been determined that declining brain health, stroke, lung disease, heart disease, and cancer are all linked to cigarette smoking.

The good news is that, with time, quitting smoking can reverse many of the negative effects of smoking. Speak with your healthcare provider if you have concerns.