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Smoking Kills
[align=left]Smoking - health risks
Reviewed by Dr Gavin Petrie, consultant chest physician
You can eat five portions of fruit and veg a day and exercise regularly, but healthy behaviour means little if you continue to smoke.
The message that 'smoking is bad for you' is an old one, so not everyone gives it their full attention. Below we list the health risks of smoking.
Term watch
‘Cardiovascular’ means the heart and circulation.
Cardiovascular disease causes:
# poor circulation
# angina (chest pains)
# heart attacks
# stroke.
Why quit smoking?
Most people know that smoking can cause lung cancer, but it can also cause many other cancers and illnesses.
Smoking kills around 114,000 people in the UK each year.
Of these deaths, about 42,800 are from smoking-related cancers, 30,600 from cardiovascular disease and 29,100 die slowly from emphysema and other chronic lung diseases.
How do cigarettes damage health?
Cigarettes contain more than 4000 chemical compounds and at least 400 toxic substances.
When you inhale, a cigarette burns at 700°C at the tip and around 60°C in the core. This heat breaks down the tobacco to produce various toxins.
As a cigarette burns, the residues are concentrated towards the butt.
The products that are most damaging are:
* tar, a carcinogen (substance that causes cancer)
* nicotine is addictive and increases cholesterol levels in your body
* carbon monoxide reduces oxygen in the body
* components of the gas and particulate phases cause chronic obstructive pulmonary disorder (COPD).
The damage caused by smoking is influenced by:
* the number of cigarettes smoked
* whether the cigarette has a filter
* how the tobacco has been prepared.
Smoking affects how long you live
Research has shown that smoking reduces life expectancy by seven to eight years.
Did you know?
On average, each cigarette shortens a smoker's life by around 11 minutes.
Of the 300 people who die every day in the UK as a result of smoking, many are comparatively young smokers.
The number of people under the age of 70 who die from smoking-related diseases exceeds the total figure for deaths caused by breast cancer, AIDS, traffic accidents and drug addiction.
Non-smokers and ex-smokers can also look forward to a healthier old age than smokers.
Major diseases caused by smoking
Cardiovascular disease
Cardiovascular disease is the main cause of death due to smoking.
Hardening of the arteries is a process that develops over years, when cholesterol and other fats deposit in the arteries, leaving them narrow, blocked or rigid. When the arteries narrow (atherosclerosis), blood clots are likely to form.
Smoking accelerates the hardening and narrowing process in your arteries: it starts earlier and blood clots are two to four times more likely.
Cardiovasular disease can take many forms depending on which blood vessels are involved, and all of them are more common in people who smoke.
A fatal disease
Blood clots in the heart and brain are the most common causes of sudden death.
o Coronary thrombosis: a blood clot in the arteries supplying the heart, which can lead to a heart attack. Around 30 per cent are caused by smoking.
o Cerebral thrombosis: the vessels to the brain can become blocked, which can lead to collapse, stroke and paralysis.
o If the kidney arteries are affected, then high blood pressure or kidney failure results.
o Blockage to the vascular supply to the legs may lead to gangrene and amputation.
Smokers tend to develop coronary thrombosis 10 years earlier than non-smokers, and make up 9 out of 10 heart bypass patients.
Cancer
Smokers are more likely to get cancer than non-smokers. This is particularly true of lung cancer, throat cancer and mouth cancer, which hardly ever affect non-smokers.
The link between smoking and lung cancer is clear.
o Ninety percent of lung cancer cases are due to smoking.
o If no-one smoked, lung cancer would be a rare diagnosis - only 0.5 per cent of people who've never touched a cigarette develop lung cancer.
o One in ten moderate smokers and almost one in five heavy smokers (more than 15 cigarettes a day) will die of lung cancer.
The more cigarettes you smoke in a day, and the longer you've smoked, the higher your risk of lung cancer. Similarly, the risk rises the deeper you inhale and the earlier in life you started smoking.
For ex-smokers, it takes approximately 15 years before the risk of lung cancer drops to the same as that of a non-smoker.
If you smoke, the risk of contracting mouth cancer is four times higher than for a non-smoker. Cancer can start in many areas of the mouth, with the most common being on or underneath the tongue, or on the lips.
Other types of cancer that are more common in smokers are:
o bladder cancer
o cancer of the oesophagus
o cancer of the kidneys
o cancer of the pancreas
o cervical cancer
COPD
Chronic obstructive pulmonary disease (COPD) is a collective term for a group of conditions that block airflow and make breathing more difficult, such as:
Term watch
Chronic means long term, not severe.
o emphysema - breathlessness caused by damage to the air sacs (alveoli)
o chronic bronchitis - coughing with a lot of mucus that continues for at least three months.
Smoking is the most common cause of COPD and is responsible for 80 per cent of cases.
It's estimated that 94 per cent of 20-a-day smokers have some emphysema when the lungs are examined after death, while more than 90 per cent of non-smokers have little or none.
COPD typically starts between the ages of 35 and 45 when lung function starts to decline anyway.
Quitting can help
Lung damage from COPD is permanent, but giving up smoking at any stage reduces the rate of decline in lung capacity.
In smokers, the rate of decline in lung function can be three times the usual rate. As lung function declines, breathlessness begins.
As the condition progresses, severe breathing problems can require hospital care. The final stage is death from slow and progressive breathlessness.
Did you know?
A single cigarette can reduce the blood supply to your skin for over an hour.
Other risks caused by smoking
* Smoking raises blood pressure, which can cause hypertension (high blood pressure) - a risk factor for heart attacks and stroke.
* Couples who smoke are more likely to have fertility problems than couples who are non-smokers.:001_tt2:
* Smoking worsens asthma and counteracts asthma medication by worsening the inflammation of the airways that the medicine tries to ease.
* The blood vessels in the eye are sensitive and can be easily damaged by smoke, causing a bloodshot appearance and itchiness.
* Heavy smokers are twice as likely to get macular degeneration, resulting in the gradual loss of eyesight.
:001_tt2:
* Smokers run an increased risk of cataracts.
* Smokers take 25 per cent more sick days year than non-smokers.
* Smoking stains your teeth and gums.
* Smoking increases your risk of periodontal disease, which causes swollen gums, bad breath and teeth to fall out.
* Smoking causes an acid taste in the mouth and contributes to the development of ulcers.
:001_rolleyes:
* Smoking also affects your looks: smokers have paler skin and more wrinkles. This is because smoking reduces the blood supply to the skin and lowers levels of vitamin A.
Smoking and impotence
For men in their 30s and 40s, smoking increases the risk of erectile dysfunction (ED) by about 50 per cent.
Did you know?
The British Medical Association estimates that up to 120,000 men have ED because of smoking.
Erection can't occur unless blood can flow freely into the penis, so these blood vessels have to be in good condition.
Smoking can damage the blood vessels and cause them to degenerate: nicotine narrows the arteries that lead to the penis, reducing blood flow and the pressure of blood in the penis.
This narrowing effect increases over time, so if you haven't got problems now, things could change later.:lol: :lol:
Erection problems in smokers may be an early warning signal that cigarettes are already damaging other areas of the body - such as the blood vessels that supply the heart.
Smoking and others
There are many health-related reasons to give up cigarettes - not just for smokers, but to protect those around you.
Babies born to mothers who smoke during pregnancy are twice as likely to be born prematurely and with a low birth weight.
Passive smoking
The 'side-stream' smoke that comes off a cigarette between puffs carries a higher risk than directly inhaled smoke.
:clap: :clap:
Children who grow up in a home where one or both of their parents smoke have twice the risk of getting asthma and asthmatic bronchitis. They also have a higher risk of developing allergies.
Infants under two years old are more prone to severe respiratory infections and cot death.
For adults, passive smoking seems to increase the risk of lung cancer, but the evidence for an increased risk of heart disease is not yet conclusive.
Thinking about quitting?
As well as reducing your risk of getting a smoking-related illness, there are other benefits to quitting smoking.
* General health improves - tiredness and headaches can be linked to smoking.
* Your sense of taste and smell improve.:rotflmao: :rotflmao:
* Your heart will be less strained and work more efficiently.
Stopping smoking is the single biggest thing you can do to improve your health, but it's a difficult task.
Smokers who are trying to kick their habit may be disappointed to find there's no single quit method that guarantees success.
The weight of evidence suggests that smokers should set a date to stop, and do their best to quit completely from this point.
On average it takes four to five attempts to give up, and there are a number of things that can help willpower:
* nicotine replacement treatment (NRT) in the form of gum, skin patches or nasal spray
* Zyban (bupropion) is a medicine that's licensed to help smoking cessation
* behaviour modification programmes
* alternative therapies such as acupuncture and hypnosis.
Based on a text by Dr Carl J Brandt[/align]
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As far as I know passive smoking is more dangerous than direct smoking
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The Dope on Nicotine
by Rochelle Schwartz-Bloom and Gayle Gross de Núñez
If it weren't for nicotine, people wouldn't smoke tobacco. Why? Because of the more than 4,000 chemicals in tobacco smoke, nicotine is the primary one that acts on the brain, altering people's moods, appetites, and alertness in ways they find pleasant and beneficial. As the noted tobacco researcher M.A.H. Russell once wrote, "There is little doubt that if it were not for the nicotine in tobacco smoke, people would be little more inclined to smoke than they are to blow bubbles or to light sparklers."*
Unfortunately, as is widely known, nicotine has a dark side: It is highly addictive. Once smokers become hooked on it, they must get their fix of it regularly, sometimes several dozen times a day. Cigarette smoke contains 43 known carcinogens, which means that long-term smoking can amount to a death sentence. In the U.S. alone, 420,000 Americans die every year from tobacco-related illnesses.
Breaking nicotine addiction is not easy. Each year, nearly 35 million people make a concerted effort to quit smoking. Sadly, less than 7 percent succeed in abstaining for more than a year; most start smoking again within days.
So what is nicotine, and how does it insinuate itself into the smoker's brain and very being? Here, follow the trail nicotine blazes through the body, from mouth to brain.
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Drug
Like cocaine derived from coca leaves and morphine drawn from opium poppies, the nicotine found in tobacco is a potent drug. Smokers, and even some scientists, say it offers certain benefits. One is enhanced performance. One study found that nonsmokers given doses of nicotine typed about 5 percent faster than they did without it. To greater or lesser degrees, users also say nicotine helps them to maintain concentration, reduce anxiety, relieve pain, and even dampen their appetites (thus helping in weight control). Unfortunately, nicotine can also produce deleterious effects beyond addiction. At high doses, as are achieved from tobacco products, it can cause high blood pressure, distress in the respiratory and gastrointestinal systems, and an increase in susceptibility to seizures and hypothermia.
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Nicotine
First isolated as a chemical compound in 1828, nicotine is a clear, naturally occurring liquid that turns brown when burned and smells like tobacco when exposed to air. It is found in several species of plants, including tobacco and, perhaps surprisingly, in tomatoes, potatoes, and eggplant (though in extremely low quantities that are pharmacologically insignificant for humans). In tobacco, the highest concentration of nicotine appears in the plant's topmost leaves. A poisonous alkaloid, nicotine at high dosages has been used in everything from insecticides to darts designed to bring down elephants.
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Cigarette
As simple as it looks, the cigarette is a highly engineered nicotine-delivery device. For instance, when tobacco researchers found that much of the nicotine in a cigarette wasn't released when burned but rather remained chemically bound within the tobacco leaf, they began adding substances such as ammonia to cigarette tobacco to release more nicotine. Ammonia helps keep nicotine in its basic form, which is more readily vaporized by the intense heat of the burning cigarette than the acidic form. Most cigarettes for sale in the U.S. today contain 10 milligrams or more of nicotine. By inhaling smoke from a lighted cigarette, the average smoker takes in one to two milligrams of vaporized nicotine per cigarette.
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[align=left] Addiction
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Addiction
Smoker & Nicotine
As early as the 16th century, it was known that tobacco use led to addiction. In 1527, the Spanish historian Bartolomé de Las Casas wrote, "I have known Spaniards on the island of Hispaniola, who were accustomed to taking [cigars] and who, being reproved and told that this was a vice, replied that they were not able to stop." Today, we know that nicotine is the cause of this dependency, and only a miniscule amount is needed to fuel addiction. Research suggests that manufacturers would have to cut nicotine levels in a typical cigarette by 95 percent to forestall its
Heart and Lungs
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When a smoker puffs on a lighted cigarette, smoke, including vaporized nicotine, is drawn into the mouth. The skin and mucosal lining of the mouth absorb some nicotine, but the remainder flows straight down into the lungs, where it easily diffuses into the blood vessels lining the lung walls. The blood vessels carry the nicotine to the heart, which then pumps it directly to the brain. While most of the effects a smoker seeks occur in the brain, the heart takes a hit as well. Studies have shown that a smoker's first cigarette of the day can increase his or her heart rate by 10 to 20 beats a minute.
Brain
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Scientists have found that a smoked substance reaches the brain more quickly than one swallowed, snorted (such as cocaine powder), or even injected. Indeed, a nicotine molecule inhaled in smoke will reach the brain within 10 seconds. The nicotine travels through blood vessels, which branch out into capillaries within the brain. Capillaries normally carry nutrients, but they readily accommodate nicotine molecules as well. Once inside the brain, nicotine, like most addictive drugs, triggers the release of chemicals associated with euphoria and pleasure.
Neurons
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Just as it moves rapidly from the lungs into the bloodstream, nicotine (shown here as green chevrons) also easily diffuses through capillary walls. It then migrates to the spaces surrounding neurons -- gangly cells that transmit nerve impulses throughout the nervous system. These impulses are the basis of our thoughts, feelings, and moods.
Neurotransmitters
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To transmit nerve impulses to its neighbor, a neuron releases chemical messengers known as neurotransmitters (shown here as orange bars). Like nicotine molecules, the neurotransmitters drift into the so-called synaptic space between neurons, ready to latch onto the receiving neuron and thus deliver a chemical "message" that triggers an electrical impulse.
Receptors
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The neurotransmitters -- in our example, acetylcholine, a common variety -- bind onto receptors (shown here as green blossoms) on the surface of the recipient neuron. This opens channels in the cell surface through which enter ions, or charged atoms, of sodium. This generates a current across the membrane of the receiving cell, which completes delivery of the "message."
Binding
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An accomplished mimic, nicotine competes with acetylcholine to bind to the acetylcholine receptor. It wins and, like the vanquished chemical, opens ion channels that let sodium ions into the cell (see light blue dots). But there's a lot more nicotine around than acetylcholine, so a much larger current spreads across the membrane. This bigger current causes increased electrical impulses to travel along certain neurons. With repeated smoking, the neurons adapt to this increased electrical activity, and the smoker becomes dependent upon the nicotine.
Caudate Nucleus
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The caudate nucleus, an area of the brain that controls voluntary movement, illustrates this adaptation. Without the nicotine, neurons cannot maintain impulses at the levels they had previously. As a result, some smokers experience hand tremors between cigarettes. These "smoker's tremors" may be hard to see, because a smoker hides them by smoking another cigarette. The tremors may be a sign of withdrawal, but they will go away if the smoker gives up smoking for good.
reference
http://www.pbs.org/wgbh/nova/cigarette/nicotine.html
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