H o w Tobacco W o r k s
Nicotine in inhaled tobacco smoke can travel from the lungs to the brain in about 7 seconds. In low concentrations (an average cigarette yields about 1 mg of absorbed nicotine), it acts as a stimulant and is the main factor responsible for the addiction forming properties of tobacco smoking. Nicotine reaches the brain very quickly after the smoker takes a puff, but its effects start to wear off within a few minutes. This often leads the smoker to get another cigarette. If the smoker doesn’t smoke again soon, withdrawal symptoms kick in and get worse over time. The typical smoker takes about 10 puffs from each cigarette. A person smoking a pack per day gets about 200 “hits” of nicotine each day. The nicotine in tobacco can be as addictive as cocaine or heroin. Only about 7% of smokers who attempt to stop smoking can refrain from smoking for more than a year.
According to the American Heart Association, “nicotine addiction has historically been one of the hardest addictions to break”. The nicotine content in cigarettes has actually slowly increased over the years, and one study found that there was an average increase of 1.6% per year between the years of 1998 and 2005.
Nicotine can both stimulate and depress the central nervous system. It causes glucose to be released by the liver and epinephrine (adrenaline) from the adrenal glands. Nicotine reaches the brain very quickly after it is ingested or inhaled into the lungs, and it stimulates the release of neurotransmitters and hormones. For example, Nicotine appears to aid concentration and memory due to the increase of acetylcholine. It also appears to enhance alertness due to increases of acetylcholine and norepinephrine in the bloodstream. Pain sensations are reduced by the increases of acetylcholine and beta-endorphin. Anxiety is reduced by the increase of beta-endorphin. Nicotine works very much like other addicting drugs, by flooding the brain’s reward circuits with dopamine.
Research seems to explain the contradiction that allows nicotine to be considered both a stimulant and a relaxant. When smokers want a stimulating effect, they take short quick puffs, which produce a low level of blood nicotine. This stimulates nerve transmissions. When they wish to relax, they take deep puffs, which produce a high level of blood nicotine, which then depresses the passage of nerve impulses. This produces a mild sedative effect. In these effects nicotine is relatively unique in comparison to most other drugs, as its functionality changes from stimulant to sedative or pain killer when dosages are increased.
The amount of nicotine absorbed by the body from smoking depends on many factors, including the type of tobacco, whether the smoke is inhaled, and whether a filter is used. For chewing tobacco, dipping tobacco, and snuff, which are held in the mouth between the lip and gum, or taken in the nose, the amount released into the body tends to be much greater than smoked tobacco.
Tobacco Tutorial: Page 11 of 21