Nicotine
• Per capita sales of cigs-peaked in early 60s-40% of adults smoked; today-21%
• 74% of Amer. Smokers-consider themselves addicted
• Avg. day in 2006-4,000 ages 12-17-smoked for first time
• 100 million-estimated # of people worldwide who died prematurely in 20th century
• Higher the education level-less likely to smoke• College grads-% less than half of non-grads• Men-24%; women 18%• Most likely-25-44 yrs.-25.6%• Below poverty level-30.5%; above-21.7%
How Nicotine Moves Through the Body
• Absorbed rapidly into blood through lungs; in brain within seconds
• Chew-takes longer; cig-1mg nicotine;chew-3-5 mg; both result in about same peak concentrations in blood
• More than 4,000 chemicals found in tobacco smoke
• Cigars-usually don’t inhale; absorbed through mucous membranes
• Peak concentration in lungs, blood, & brain-about 10 min
• Eliminated very quickly-almost all gone in 30 min
Is Nicotine Addictive?
• Affects brain quickly; activates reward pathways (dopamine)
• Effects dissipate quickly• Tolerance develops rapidly• Withdrawal: irritability, craving, depression,
anxiety, cognitive & attention deficits, sleep disturbances, increased appetite
• Peak in several days; usually subside in a few weeks
• Recent research: decreased levels of MAO-results in higher dopamine levels-may contribute to addiction
• Acetaldehyde-found in tobacco smoke-increases reinforcing qualities of nicotine, especially for adolescents
Carbon Monoxide & Tar
• Carbon monoxide: odorless, colorless, toxic gas
• Attaches to hemoglobin-prevents oxygen from getting to body from lungs
• Accumulates over time• Produces cardiovascular disease
• Tar: quantity varies in cigs; last 1/3 of cig-contains 50%
• Adheres to cells in lungs-cilia can’t function effectively
• Permits carcinogenic compounds that normally would have been eliminated to settle on tissue=lung cancer
Effects on Brain & Mental Function
• Stimulates a subtype of an ACh receptor-called the nicotinic acetylcholine receptor; many brain areas
• Excites cells & increases cell-cell signaling• Increases activity in areas associated with
memory and other cognitive functions; stimulation improves memory
• May help Alzheimer’s patients; adult ADHD; improve cognitive functioning in schizophrenia
• May lead to depression in some adolescents• Smoking adolescents: 2x as likely as
nonsmokers to experience an episode of major depression
Heart Disease
• Nicotine causes release of adrenaline-increases heart rate and blood pressure-heart works harder
• Toxic to inner linings of blood vessels; hardens them
• Smoking-30% of all deaths from coronary heart disease
• Raises risk of fatal heart attack 2-4x
• Increases platelet adhesiveness in blood=increased risk of blood clots=heart attack or stroke
• Increases cholesterol=atherosclerosis-fatty deposits impede blood flow
Other Problems Related to Smoking
• COPD: 80-90% of cases are the result of smoking• Adolescents: 5+ cigs a day-40% more likely to
develop asthma• 90% of approximately 213,000 new cases of lung
cancer in U. S. each year-caused by smoking• Increasing numbers of women; since 1988 lung
cancer has exceeded breast cancer deaths• In U. S.-about 30% of cancer deaths of all types-
linked to smoking
• Increased risk: 2-27x larynx; 13x mouth/lips; 2-3x bladder; 2x pancreatic; 5x kidneys and uterus
• Smokeless: leukoplakia (white spots) & erythroplakia (red spots)-inside mouth and nose; precancerous changes
Secondhand & Sidestream Smoke
• Sidestream-higher concentrations of carcinogens than secondhand or smoke taken in by smoker
• Nonsmoking adults: raises risk of heart disease by 25-30% (both men and women); lung cancer: +20-30%
• SIDS: 430 deaths per year in U. S.
• Children whose parents smoke-increased risk of bronchitis, middle-ear disease, wheezing, childhood asthma
• 46,000 premature deaths from heart disease; 3,000 from cancers
Prenatal & Postnatal Effects
• Babies: can go through symptoms of withdrawal
• Also cyanide and carbon monoxide to fetus• Smaller, lighter, smaller head circumference• Affects brain and mental functions after birth
(may be permanent)• Verbal and math abilities; hyperactivity;
greater likelihood of nicotine addiction
• Dad smokes-more likely to have children who develop childhood cancers.
• One study: fathers who smoked 20+ per day-42% increased risk of having a child with cancer; smoked 10-20: +31% risk
• Smoking may damage sperm, leading to cancer-causing alterations of DNA
Quitting
• Not just a matter of will power• About 1/3 try to quit each year; 3-5% succeed
on first try• About half quit after avg. of 8 attempts• Within 1 yr: risk of coronary heart disease is ½
of a smoker• Within 5-10 yrs: risk of stroke reduced to that
of nonsmoker