Nicotine is an alkaloid found in the nightshade family of plants, predominantly in tobacco. An alkaloid is an organic compound made up of carbon, hydrogen, nitrogen and sometimes oxygen (nicotine contains no oxygen). Coffee is another example of an alkaloid, also a stimulant, which explains why coffee-drinkers are addicted to it! Tomato, potato and eggplant also contain nicotine but in lower quantities. Nicotine constitutes 0.3 to 5% of the tobacco plant by dry weight and is a powerful neurotoxin. In fact, it was widely used as an insecticide in the past. As it is a powerful stimulant, it has dependence-forming properties which make tobacco smoking a tough habit to kick. According to the American Heart Association nicotine addiction has, historically, been one of the toughest addictions to break.
 Nicotine in the body
As nicotine enters the body it is quickly absorbed in the bloodstream and crosses the blood-brain barrier. The amount of nicotine inhaled with tobacco smoke is a fraction of what is contained in tobacco leaves. When you light a cigarette, most of the substance is destroyed by the heat. The amount of nicotine absorbed from smoking depends on the type of tobacco, whether the smoke is inhaled, and whether a filter is used. Chewing tobacco, dipping tobacco and snuff release much greater amounts of nicotine into the body.
On average it takes about 7 seconds for nicotine to reach the brain when inhaled, and it stays in the body for anywhere between five minutes to two hours.
Nicotine is known to produce mood-altering effects. It is both a stimulant and a relaxant. Consequently, it produces feelings of alertness, relaxation and calmness. It also reduces appetite and increases metabolism, so smokers often report a weight loss as well. When a cigarette is smoked, nicotine-rich blood passes from the lungs to the brain within 7 seconds and immediately stimulates the release of a host of chemicals. This results in enhanced pleasure and decreased anxiety. As the effects of nicotine last in the body from five minutes to two hours, smokers smoke a number of cigarettes a day in an effort to keep the pleasant feelings alive in the bloodstream. Most cigarettes (in the smoke inhaled) contain 0.1 to 2.8 milligrams of nicotine.
Nicotine increases the levels of dopamine, one of the key neurotransmitters actively involved in the brain, one that travels in the reward circuits in the brain. By increasing dopamine levels, nicotine acts as a chemical with intense addictive qualities.
Nicotine initially causes a rapid release of adrenaline. The adrenaline rush causes the body to dump some of its glucose stores into the bloodstream so it makes people hyperglycemic.
Research shows that, when smokers wish to achieve a stimulating effect, they take short, quick puffs which produce a low level of blood nicotine. Those who wish to relax take deep puffs which produce a high level of blood nicotine that depresses the passage of nerve impulses, causing a mild sedative effect.An average cigarette yields about 1 mg of absorbed nicotine.
How the body gets rid of nicotine
- About 80% of it is broken down to cotinine by enzymes in the liver.
- It is also metabolized in the lungs to nicotine oxide.
- Cotinine and other metabolites are excreted in the urine.
- The remaining nicotine is filtered from your blood by the kidneys.
 Quitting the Puff
The effects of nicotine on the human body are both physiological and psychological. Regular smokers use it compulsively, irrespective of its negative effects on health. Anything that turns on the reward pathway in the brain is defined by neuroscientists as ‘addictive.’ Pleasurable feelings make the smoker crave more of the experience.
A smoker becomes tolerant to nicotine’s effects over time so he needs to smoke many more cigarettes to reach the same degree of stimulation or relaxation.
What happens when a regular smoker quits? While you’re smoking, your body adapts the way it works to compensate for the effects of the nicotine. For eg. neurons in your brain may increase or decrease the number of receptors or the amount of different neurotransmitters affected by the nicotine. When nicotine is abruptly withdrawn from the body, these physical adaptations still remain. The result is that your body cannot function the same way in the absence of the drug as it did before. Anxiety, irritability, depression and craving are side-effects of the withdrawal. It would take about a month for these symptoms to fade away, the toughest period for the smoker who is trying to kick the habit. That is why many smokers revert to the habit barely a week after attempting to quit and a mere 10% are successful in giving up.
 Tips to quit smoking
- Quit cold turkey – this has proven successful for many a diehard smoker. Just wake up one morning and say you’re not going to smoke a single cigarette that day. Days turn into weeks and weeks into months and soon the demonic urge releases its hold on you.
- Work your mouth in other ways. Pop a candy, chew gum, or drink root beer. Just don’t light up.
- Use motivation. Keep a daily journal. Log in every day you’ve managed not to smoke. This should serve as motivation, and proof that you can do it – one day at a time.
- The audio tape method. There are several audio tapes that help you quit smoking. Listen to a tape for 10 minutes every day and gradually the words start to sink into your subconscious and release deeply-embedded messages about why you need that smoke.
- Be prepared for those ‘craving sessions.’ The first two weeks are the worst. Mentally ready yourself for those difficult times but stay committed to your resolve not to light up.
 Did You Know?
- Every 10 seconds a person dies from tobacco-related causes.
- The average age when people start smoking is 15, and becomes a daily smoker by age 18.
- Cigarettes are the most littered item in the world and toxic residue contained in cigarette buds get released into the environment and water supply.
- Smoking costs the U.S. approximately $97.2 billion each year in health-care costs and lost productivity.
- Smoking is directly responsible for 87% of lung cancer cases and causes most cases of emphysema and chronic bronchitis
- Every year, 77.4 million packs of cigarettes are bought or smoked by youth.
- Secondhand smoke has more toxins than inhaled smoke.
- Long-term smokers are as likely to die as a direct result of using tobacco as from all other potential causes of death combined.
- Smoking a pack of cigarettes a day adds up to about 7,500 cigarettes a year. A person with a 20 year habit — 150,000 cigarettes
 USEFUL WEBSITES
- Book Rags
- Tobacco Cessation - You Can Quit Smoking Now!
- The Quit Smoking Company