Health benefits of quitting smoking?

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 conclusions:

Smoking cessation has major and immediate health benefits for men and women of all ages. Benefits apply to persons with and without smoking-related disease.

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 continuing smokers.

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.

Immediate benefits:

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.

Long term benefits:

Cancers

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.

Cardiovascular disease

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.

Respiratory disease

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.

Reproduction

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.

Other disease processes

Smokers have an increased risk of developing duodenal and gastric ulcers. The increased risk is reduced by stopping smoking. Ulcer disease is more severe, less likely to heal, and more likely to recur in smokers. Affected smokers who quit do better than continuing smokers.

Cessation and the older smoker:

As noted above, cessation at any age carries benefits for the smoker, reducing the risk of major disease. Smoking in later life has also been associated with higher rates of physical disability, poorer self-perceived health status, higher levels of depressive symptoms, and lower levels of physical function, bone mineral density, pulmonary function, and muscle strength. Cessation therefore is an important factor in bringing about improvement in general health and well-being.