Smoking? 

The benefits of quitting below... 

When smokers quit their last cigarette, the body begins a series of changes.

The connection between smoking and colorectal cancer... People who smoke cigarettes for 20 years or more are about 40 percent more likely to die of colon cancer than are non-smokers, according to a study that blames tobacco use for about 12 percent of US colon cancer deaths. The age when smoking started also played a role, said Chao. People who started the habit before the age of 15 had a 47 percent greater risk of dying form colorectal cancer than did those who never smoked.

• At 8 hours:
          - carbon monoxide levels in blood drops to normal.
          - Oxygen level in blood increases to normal.

• At 48 hours:
          - Nerve endings start re-growing.
          - Ability to taste and smell begins to become enhanced again.

• At two weeks to three months:
          - Circulation improves.
          - Walking becomes easier.
          - Lung function increases.

• After 12 months:
          - Excess risk of coronary heart disease is decreased by half.
  
• At five years:
          - From 5 to 15 years after quitting, stroke risk is reduced to that of people who have never smoked.

• At 10 years:
          - Risk of lung cancer drops to as little as one half that of continuing smokers.
          - Risk of cancer of the mouth, esophagus, bladder, kidney and pancreas decreases.

Source: Action on Smoking and Health Foundation.