Nicotine's Effects on the Brain

Cigarette smoking still tops the list as the most preventable cause of death in the United States today, accounting for 480,000 deaths annually.

Fewer people over the age of 18 are smoking today than ever before, but the number of current smokers is still high. Estimates from the Centers for Disease Control and Prevention for 2015 indicate that 15.1 percent of the U.S. adult population, or approximately 36.5 million adults smoke cigarettes.

The nicotine in inhaled tobacco smoke moves from the lungs into the bloodstream and up to a smoker's brain within seven to 10 seconds. Once there, nicotine triggers a number of chemical reactions that create temporary feelings of pleasure for the smoker, but these sensations are short-lived, subsiding within minutes.

As the nicotine level drops in the blood, smokers feel edgy and agitated—the start of nicotine withdrawal. In order to relieve this discomfort, smokers light up another cigarette... and then another... and another. And so it goes—the vicious cycle of nicotine addiction. One cigarette is never enough, a fact that every smoker knows all too well.

In order to quit smoking successfully for the long term, it helps to understand the nature of nicotine addiction and what it takes to break free of it. In fact, smokers are often surprised to learn that they are addicted to a substance. Many of us believed that smoking was just a bad habit; something we could stop easily when we decided it was time.

Let's take a look at how nicotine affects brain chemistry and begin the educational process that will help us battle this addiction to the ground, once and for all.

When a person inhales cigarette smoke, the nicotine in the smoke is rapidly absorbed into the blood and starts affecting the brain within 10 seconds. The causes the release of adrenaline, the "fight or flight" hormone.

Physically, adrenaline increases a person's heart rate, blood pressure and restricts blood flow to the heart muscle. When this occurs, smokers experience rapid, shallow breathing and the feeling of a racing heartbeat. Adrenaline also tells the body to dump excess glucose into the bloodstream.

Nicotine also inhibits the release of insulin from the pancreas, a hormone that is responsible for removing excess sugar from a person's blood. This leaves the smoker in a slightly hyperglycemic condition, meaning he or she has more sugar in the blood than is normal.

High blood sugar acts as an appetite suppressant, which may be why smokers think their cigarettes reduce hunger.

Nicotine activates the same reward pathways in the brain that other drugs of abuse such as cocaine or amphetamines do, although to a lesser degree.

Research has shown that nicotine increases the level of dopamine in the brain, a neurotransmitter that is responsible for feelings of pleasure and well-being.

The acute effects of nicotine wear off within minutes, so smokers must continue dosing themselves frequently throughout the day to maintain the pleasurable effects of nicotine and to prevent withdrawal symptoms.

In addition to nicotine, cigarette smoke is composed of more than 7000 toxic chemicals and tar. The tar, which can vary between 7 and 20 or more milligrams per cigarette, exposes smokers to an increased risk of lung cancer, emphysema, and bronchial disorders.

Carbon monoxide in cigarette smoke increases the chance of cardiovascular diseases. The Environmental Protection Agency has concluded that secondhand smoke causes lung cancer in both smoking and non-smoking adults and greatly increases the risk of respiratory illnesses in children and sudden infant death.

Statistics show that only a small percentage (approximately 7%) of people who try to quit smoking without support are still smoke-free a year later. However, those with a quit program in place that includes education about nicotine addiction and a solid support group, do much better.

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Whether you prefer to quit cold turkey or choose to use a quit aid to help you stop smoking, realize this:

Recovery from nicotine addiction is a process of gradual release over time.

It doesn't happen overnight, but with perseverance, freedom from nicotine addiction is doable and will pay you back with benefits that go well beyond what you can probably imagine.