Unless otherwise indicated,
information in this section comes from Quit Victoria, 1995
The 1990 Report of the US
Surgeon General is devoted to smoking cessation, and has reached the following major
Smoking cessation has major and immediate health benefits for
men and women of all ages. Benefits apply to persons with and without smoking-related
Former smokers live longer than continuing smokers, and the
benefits of quitting extend to those who quit at older ages. For example, persons who quit
smoking before age 50 have one-half the risk of dying in the next 15 years compared with
Smoking cessation decreases the risk of lung cancer, other
cancers, heart attack, stroke, and chronic lung disease.
Women who stop smoking before pregnancy or during the first 3
to 4 months of pregnancy reduce their risk of having a low birthweight baby to that of
women who never smoked.
The health benefits of smoking cessation far exceed any risks
from the average 2.3 kg (5 pound) weight gain or any adverse psychological effects that
may follow quitting.
British research has confirmed that quitting at any age increases life expectancy,
provided that quitting takes place prior to the development of cancer or other serious
disease. Those who quit before the age of 35 have a life expectancy that is not
significantly different from non-smokers. For those who stop later, the risk is
intermediate between non-smokers and continuing smokers. Even those who stop between 65-74
years of age experience age-specific mortality rates beyond age 75 years appreciably lower
than those who continue to smoke.
Nicotine and carbon monoxide leave the body in the first few hours after stopping
smoking, although it may take up to two days for nicotine by-products to leave the body.
Within a month of cessation, blood pressure returns to the normal level, and lung function
has improved. After around three months, the lungs may have regained the capacity to clean
themselves properly, depending on whether irreparable lung damage has occurred, and blood
flow to the limbs will have improved.
Ten years after stopping smoking,
the ex-smoker's risk of developing lung cancer has declined to between 30-50% of the risk
in continuing smokers, and risk continues to decline with abstinence. Quitting also lowers
the risk of laryngeal cancer, and reduces the extent and severity of premalignant cellular
changes in the lining of the larynx and the lungs.
Stopping smoking halves the risk of mouth and oesophageal cancers after five years of
quitting. The risk of pancreatic cancer is also reduced, although this may only be
measurable after ten years of abstinence. The risk of bladder cancer reduces after a
number of years, but studies have conflicting findings about extent. The risk of cervical
cancer is substantially lower among former smokers than current smokers, even in the first
few years following cessation.
Smoking cessation greatly reduces the risk of coronary heart disease (CHD). Risk of
mortality is reduced by about half one year after cessation, then declines gradually.
After around 15 years of abstinence, the risk of CHD is similar to that of never-smokers.
For those smokers with diagnosed CHD, stopping smoking appears to reduce the risk of
recurrent infarction and cardiovascular death by 50% or more. Smoking cessation
substantially reduces the risk of developing peripheral vascular disease, and improves
management of the existing condition. Smoking cessation also reduces the risk of ischaemic
stroke and subarachnoid haemorrhage.
Stopping smoking reduces rates of respiratory symptoms such as cough,
sputum production and wheezing, and respiratory infections such as bronchitis and
pneumonia. In smokers with established chronic obstructive pulmonary disease (COPD),
stopping smoking improves pulmonary function by about 5% within a few months of cessation.
The accelerated decline in lung function in smokers stops with smoking cessation,
returning to the far slower rates of decline that naturally occur with ageing. With
sustained abstinence, mortality rates from COPD among former smokers decline in comparison
to continuing smokers.
The US Surgeon General has stated that 'smoking is probably the most
important modifiable cause of poor pregnancy outcome among women in the United States'.
Women who stop smoking before becoming pregnant, or who quit smoking in
the first three to four months of pregnancy, have infants with the same birthweight as
those born to women who have never smoked. Those women who stop smoking any time up to the
30th week of pregnancy have babies with higher birthweight than those who smoke throughout
pregnancy. Reducing the number of cigarettes smoked, rather than quitting completely, does
not appear to benefit birthweight of the foetus.
Smoking causes women to
reach menopause one to two years early, but former smokers have an age at natural
menopause similar to those who have never smoked.