You're probably well aware that smoking is a significant risk factor for lung cancer and other serious diseases. But did you know it also takes a toll on your brain function?

In developing countries, tobacco use is the single largest cause of premature death and memory impairment, which is shown to predict dementia. Smokers who do survive into later life may be at high risk for clinically significant cognitive decline.

Studies repeatedly find associations between smoking and physical changes in the brain, including atrophy, the partial or complete wasting away of tissue. These associations are particularly strong in individuals with other illnesses or predisposition to health problems.

For example, Multiple Sclerosis (MS) patients who smoke have almost 20 percent more brain lesions, more brain tissue atrophy, and are at greater risk for blood-brain barrier disruptions. The blood-brain barrier separates circulating blood and cerebrospinal fluid in the central nervous system.

Results from cross-sectional and case-controlled studies show that, over time, smokers experience greater cognitive decline than non-smokers and have higher incidences of dementia of all types.

Smoking can also cause strokes, or the sudden death of brain cells caused by blood clots or bleeding. Furthermore, smokers are more likely to experience daily symptoms of depression. In fact, smoking is an established risk factor for depression.

If you've tried to quit and couldn't, don't take it as a personal failure. Nicotine changes the way the brain works. It's highly addictive, especially in younger individuals (adolescents can become addicted after just a few cigarettes).

However, if you do give up smoking, you can reverse much of the damage to your brain. For example, in one study, the changes in cognitive scores of smokers who quit more than 18 months before the study began were comparable to changes in people who've never smoked. Another study, which evaluated smokers at ages 35, 43, and 53 years, found that memory decline slowed among those who quit smoking.

Smokers who continued to smoke, or who stopped less than 18 months before the start of the study cited above, showed greater cognitive decline, deterioration in memory, and loss of gray matter in areas of the brain associated with memory retrieval. These brain areas may also contribute to compromised attention, memory, and cognitive abilities that control and regulate other abilities and behaviors.

There are many tools to help individuals stop smoking. If you're ready to give up cigarettes, you can improve your chances of being successful by incorporating some of them in your smoking cessation plan.

Rafael Pajaro, MD, reviewed this article.


Richards, Marcus, PhD, Jarvis, Martin, J., DSc, Thompson,Neil, BSc, and Wadsworth, Michael E. J., PhD. "Cigarette Smoking and Cognitive Decline in Midlife: Evidence From a Prospective Birth Cohort Study." American Journal of Public Health 93(6) (2003): 994-998. Web.

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Medscape Medical News. "Cigarette Smoking Linked to Size of Brain Aneurysms." Web. 14 March 2000.

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