Why nicotine is bad for you
Nicotine is not carcinogenic, but it is highly addictive; after inhalation of smoke, nicotine reaches the brain within 20 seconds and its effects are felt within a minute.
• Nicotine is five to 10 times more potent than cocaine or morphine in producing behavioural and psychological effects associated with addiction, including feelings of pleasure, according to a report produced by the UK’s Royal College of Physicians in 2007.
• Nicotine dependence is reflected in the difficulty associated with trying to quit smoking. A 2006 report by the UK Office for National Statistics found that the majority of smokers (around 70%) want to quit, yet the success rate remains low. Fewer than 20% of people who embark on a course of treatment to quit smoking succeed in abstaining for as long as a year.
• Nicotine binds to an area of the brain known as the adrenal medulla, which increases the flow of adrenaline. This in turn causes increased blood pressure, heart rate and respiration, and these conditions exacerbate existing heart and blood pressure problems.
• Nicotine can contribute to sleep disorders. It stimulates the nervous system and when taken at nighttime it ensures that the user is alert and awake rather than deep in restorative sleep.
Why smoking is bad for you
• Smoking kills half of all regular smokers.
• Smoking was responsible for 15,500 deaths, or 12% of all deaths in Australia in 2003, according to a government report. If it doesn’t kill you, smoking may severely reduce your quality of life; in the same year smoking caused the loss of 204,700 years of healthy Australian life.
• Smokers are three times more likely to suffer a heart attack than people who have never smoked, a 1990 study by the US Department of Health and Human Services found; each cigarette smoked per day increases the risk by 5.6%.
• Smoking causes nine out of 10 cases of lung cancer and a third of all cancer deaths, according to a 2006 British study.
• Cigarette smoke contains more than 4,000 compounds, many of which are toxic and damage our cells. Included in these compounds are acetone, used in nail polish remover; arsenic, often found in insecticides; benzene, a cancer-causing agent; ammonia, used in dry cleaning; and cadmium, which causes cancer of the liver and kidney and brain damage.
• Tar is the main cause of lung and throat cancer in smokers. It stains teeth and skin, and damages the fine hairs in the lungs making breathing difficult and reducing their protective effect against infection. Around 70% of the tar in cigarettes is deposited in a smoker’s lungs.
• A 2007 paper in The Lancet found that smoking causes 73% of chronic obstructive pulmonary diseases (COPD). COPD damages airways and causes them to narrow, making it harder for air to pass in and out of the lungs.
• In people with high blood pressure, smoking may exacerbate the already increased risk of a blood vessel bursting inside the brain, known as intracerebral stroke.
Related reading: Can nicotine save your brain?
Becky McCall is a freelance science writer based in Bristol, England. She also produces webcasts and is presenting a new British TV series.
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