Recently new statistics came out that show that 48.8 million people in the US (19% of the population) still smoke. 22 % of the population are male, 17% female. Smoking is responsible for 20% of all deaths in the US (1 in 5 deaths). It is interesting to note that in the older age group (above the age of 65) only 8% are smoking, but 22 % of the 25 to 44 year old group is smoking. Among the American population Native Americans have the highest percentage of smokers (32% are smokers). 10% of Americans of Asian descend smoke. Blacks, Whites and Hispanics are placed in between them and the American Indians. Finally, people who can least afford it (who are below the poverty level) have the highest percentage of smokers (29% smoke) while 18% of people above the poverty level smoke. Education seems to have a protective effects when it comes to smoking: of the least educated group of people 45% are smokers while only 5% with postgraduate education smoke.
Effects of cigarette smoke on the body
As this link shows the concoction of various ingredients in the smoke of cigarettes causes various parts of the body to react differently to these chemicals. Here is a rundown of diseases caused by smoking cigarettes.
1. Lung cancer: This is the most common cause of death in women who smoke, more common now than breast cancer. 90% of lung cancers in women are due to smoking. The same was true in males, but as a group they now smoke less than in the past.
2. Other cancers: cervical cancer, kidney cancer, pancreatic cancer, bladder, esophageal, stomach, laryngeal, oral, and throat cancers are all caused by smoking. Recently acute myeloid leukemia, a cancer of the bone marrow has been added to the list of smoking related cancers.
3. Abdominal aortic aneurysm: As cigarette smoke destroys elastic tissue, it is no wonder that the loss of support of the wall of the aortic artery leads to the development of large pouches, which eventually rupture with a high mortality rate due to massive blood loss.
4. Infections of lungs and gums: Smokers are prone to infections of the lungs (pneumonia) and of the gums (periodontitis).
5. Chronic lung diseases: emphysema, chronic bronchitis, asthma.
6. Cataracts: lack of perfusion of the lens leads to premature cataract formation.
7. Coronary heart disease: hardening of the coronary arteries, which leads to heart attacks, is very common in smokers.
8. Reproduction: reduced fertility in mothers, premature rupture of membranes with prematurely born babies; low birth weight; all this leads to higher infant mortality. Sudden infant death syndrome is found more frequently in children of smoking moms (Ref. 1).
9. Intermittent claudication: after decades of smoking the larger arteries in the legs are hardening and not enough oxygen reaches the muscles to walk causing intermittent pausing to recover from the muscle aches. If it is feasible a cardiovascular surgeon may be able to do a bypass surgery to rescue the legs, often though this is not feasible and the patients lower legs or an entire lower limb may have to be amputated.
10. Others: osteoporosis is more common in smokers; poor eye sight develops due to age-related macular degeneration that sets in earlier and due to tobacco amblyopia, a toxic effect from tobacco on the optic nerve; hypothyroidism is aggravated by smoking and menopause occurs earlier.
What happens in the lung tissue in smokers?
Ref. 1 gives a detailed rundown of the changes in the lung tissue as a result of exposure to cigarette smoke. The various components of cigarette smoke lead to an activation of special white blood cells, called monocytes that after stimulation turn into tissue macrophages. In addition neutrophils (regular white blood cells) also get stimulated. Between them they produce cytokines and chemokines and the neutrophils secrete elastase that digests elastic tissue in the lungs. Breakdown products of the elastic tissue serve as a powerful stimulus to the immune system to mount an autoimmune response. After some time of being exposed to cigarette smoke the immune system considers part of the lining of the lungs as foreign and cytotoxic lymphocytes attack the lining of the air sacs (alveoli). Lung specialists consider chronic obstructive pulmonary disease (COPD or emphysema) to be an autoimmune disease (Ref.1).
The sad part is that when this condition has progressed far enough, even quitting smoking may be too late to stop the autoimmune disease by itself as the body has been sensitized and the immune system is convinced that the altered lung tissue should be attacked. Add to this that carcinogenic substances and toxins in cigarette smoke damage the DNA of all cells and the energy producing mitochondria, and the stage is set for the combination of chronic inflammation and the release of free radicals to cause all of the diseases mentioned above.
Quit smoking still important
It is extremely important to quit as soon as possible to avoid the full-fledged sensitization of the immune system against ones own lung tissue. Studies have shown that 36% of survivors of heart attacks will successfully quit, 21% of healthy men with a known risk of cardiovascular disease will quit when asked to do so and 8% of pregnant women will quit. When a physician examines a patient in the office and asks a smoker to quit smoking 2% of these smokers will respond and still not smoke 1 year after this doctor’s visit. This may not sound like much, but it is an encouraging effect. Perhaps the most important fact is what I mentioned in the beginning of this blog: the least educated group of people smoked the most (45%) while the most educated people smoked the least (5% of people with a postgraduate education). My hope is that the Internet and other educational media will contribute to education to convince people how important prevention is.
Pharmacological assistance to quit smoking
Nicotine replacement therapy can involve any of 2- and 4-mg nicotine polacrilex gum, transdermal nicotine patches, nicotine nasal spray, the nicotine inhaler or nicotine lozenges. Discuss with your doctor what may be best in your case. Typically one of these products is used for 3 to 6 months.
Bupropion is an antidepressant with a nicotinic acetylcholine receptor affinity. Bupropion is useful to help with the withdrawal from nicotine addiction, which occurs in depressed or non-depressed people. It strictly has to do with the stimulation of the nicotinic acetylcholine receptor. Typically the dose is 150 mg of a sustained released bupropion tablet per day for 7 days prior to stopping smoking, then at 300 mg (two 150-mg sustained-release doses) per day for the next 6 to 12 weeks. 44% quit at 7 weeks versus 19% of controls. A newer nicotine partial receptor stimulator, varenicline, has been compared to bupropion. It was slightly more effective in helping people to get off cigarettes. Varenicline is started at a dose of 0.5 mg per day for 3 days, then 0.5 mg twice daily for 4 days, followed by a maintenance dose of 1 mg twice daily. If nausea is a problem, lower doses can be used. Varenicline has been approved for a 3-month period with an option of a second 3-month period, if relapse occurs. Discuss with your doctor what is best for you.
According to Ref. 1 a combination therapy of bupropion and nicotine patch was more effective than either one alone.
Will power, hypnotherapy
Hypnotherapy to quit smoking has been popular, but is not as effective as it is often claimed. Will power, measured by the “placebo” response is quite effective given the fact that nicotine is very addictive and yet 19% in the placebo group were able to quit on their own. According to Ref. 1 varenicline treatment for 12 weeks produced abstinence for 9 to 52 weeks and was compared to bupropion and placebo. The abstinence rates were 23%, 15%, and 10% for varenicline, bupropion, and placebo. This means that will power was still 2/3 as effective as bupropion and 43% as effective as varenicline. Don’t underestimate will power!
The best scenario is to never start smoking. The second best is to quit as soon as possible. Unfortunately, the third scenario of continuing to smoke is still very prevalent worldwide. I have seen the damage done first hand in practicing medicine, which motivated me to never smoke. But I am aware of the difficulties of quitting because of the highly addictive nature of cigarette smoking. Where is the support from governments on this? The problem is that the government benefits from taxation of cigarettes. Nevertheless it is laudable that there are government sites through the CDC to help you quit smoking.
At the end we are all responsible for our own health. If you are presently smoking, psych yourself up for the day that you will quit. Quitting means that you are deciding actively to live longer. Studies have shown that it takes often several attempts before you eventually quit successfully.More information on some of the topics mentioned:
1. Lung cancer and other cancers: http://nethealthbook.com/cancer-overview/overview/epidemiology-cancer-origin-reason-cancer/
3. Chronic obstructive pulmonary disease: http://nethealthbook.com/lung-disease/chronic-obstructive-pulmonary-disease-copd/
1. Mason: Murray and Nadel’s Textbook of Respiratory Medicine, 5th ed.© 2010 Saunders
Last edited Nov. 7, 2014