The effects that nicotine has on the brain and on the body.
The reasons why people start smoking are different to the reasons why people continue to smoke and find it almost impossible to give up.
Up until fairly recently most people, especially non-smokers, considered smoking to be a personal choice and that if a smoker really wanted to quit, he could easily do so.
Now, it has been medically proven, recognised and more widely accepted that the reason people continue to smoke, despite the severe health risks smoking entails, is because nicotine is a highly addictive drug.
In fact, some doctors have reported that nicotine is just as addictive as heroin or cocaine, which indicates quite clearly as to how people become hooked so rapidly and stay hooked for so long.
Although the amount of nicotine that enters the body is extremely small, it is still enough for smokers to become dependant on nicotine, thus developing a nicotine dependency, which makes it extremely difficult for them to stop smoking.
Nicotine is an organic compound that is found naturally in the tobacco plant. It is composed of carbon, nitrogen, hydrogen and oxygen and belongs to a group of compounds called alkaloids. Plants usually produce these types of chemical poisons so that animals are deterred from eating them.
In high concentrations nicotine acts as a nerve poison and it is used in insecticides. However, in small amounts, nicotine is a stimulant that enhances brain activity and concentration and improves cognitive processing as well as a person's memory. On the downside, nicotine increases blood pressure and heart rate, causes you to breathe faster and less deeply and it constricts the arteries.
Nicotine also suppresses the appetite, which is one of the main reasons why many women are not keen on giving up smoking. They assume that they will eat more, which will consequently lead to gaining a lot of weight.
Once smokers become dependant on nicotine, they may experience strong physical and emotional withdrawal symptoms if they try to give up. These symptoms may include irritability, dizziness, anxiety, headaches, lack of concentration, disturbed sleeping patterns, feelings of anger, depression, tiredness as well as incredible cravings for more nicotine.
These withdrawal symptoms are at their highest during the first 72 hours after giving up, after which they lesson slightly. Generally, after about 6 weeks these symptoms subside, although an ex smoker may still possess a desire to smoke 6 months or even a year after quitting.
When inhaled through cigarette smoking, nicotine is rapidly absorbed into the lungs and enters the blood vessels that are contained in the tissue that line the lungs. From these tiny blood vessels, the nicotine enters the bloodstream and travels directly to the brain. This powerful drug reaches the brain within ten seconds and produces immediate feelings of pleasure or euphoria, amongst other stimulating effects.
Nicotine does not stay in the body for very long and is quickly broken down by various enzymes and chemical reactions. It has a half-life of around 40 minutes, which means that after this amount of time the nicotine loses half of its effect and the smoker will soon feel the need to light up another cigarette.
When you exercise, you actually metabolise the nicotine in your body faster. This means that the level of nicotine in the body and in the brain decreases more quickly. Once the nicotine is metabolised, the body usually rids itself of the drug and the smoker must therefore smoke another cigarette in order to get the levels back up to a satisfying measure.
Some people possess an enzyme in their body that is not as effective as other people's in breaking down and metabolising the nicotine. As a result the nicotine stays in their brain and bloodstream for longer, meaning that they will smoke less, as the high levels of nicotine needed to give them pleasure are maintained in the body for much longer.
It has been discovered through scientific studies that nicotine increases the levels of dopamine in a smoker's brain.
Dopamine is linked to the pleasure and reward system of the brain and it releases feelings of enjoyment, as well as motivating a person to repeat certain rewarding activities that are usually vital for the body to survive, such as eating when you are hungry.
Smokers possess 40% less of a crucial enzyme in the brain that breaks down dopamine than non-smokers. As dopamine is not broken down as efficiently in smokers and the pleasurable effects are maintained and due to the release of extra dopamine through the nicotine, the brain therefore tries to reward the behaviour that has produced the increased amounts of dopamine. That behaviour or activity must also be maintained if the levels of dopamine and feelings of pleasure are to be sustained.
This is why smokers have a need to smoke more and try to maintain the levels of nicotine in the body. The absence of nicotine after a short period of time, can lead to intense physical and mental withdrawal symptoms, which are immediately relieved upon smoking another cigarette.
Over time, the body develops a tolerance to nicotine and its pleasurable effects begin to wear off after a while. For this reason the smoker gradually increases the number of cigarettes that he smokes in a day in order to maintain the same feelings of pleasure.
In summary, research has proven that nicotine is a highly addictive substance found in cigarettes, which causes chemical alterations in the brain that lead to a constant need for the drug.
Thus, the reason that so many people continue to smoke becomes somewhat clearer.