Drug effects

Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. It can be consumed, used as an organic pesticide, and in the form of nicotine tartrate it is used in some medicines. In consumption it most commonly appears in the forms of smoking, chewing, snuffing, or dipping tobacco, or snus.

There are many species of tobacco, which are all encompassed by the plant genus Nicotiana. The word nicotiana (as well as nicotine) was named in honor of Jean Nicot, French ambassador to Portugal, who in 1559 sent it as a medicine to the court of Catherine de Medici.

Short-term effects

When a person smokes a cigarette, the body responds immediately to the chemical nicotine in the smoke. Nicotine causes a short-term increase in blood pressure, heart rate, and the flow of blood from the heart. It also causes the arteries to narrow. Carbon monoxide reduces the amount of oxygen the blood can carry. This, combined with the effects produced by nicotine, creates an imbalance in the demand for oxygen by the cells and the amount of oxygen the blood is able to supply.

Tobacco effects on the body

More people die from smoking-related diseases than from illicit drugs, alcohol and road accidents combined.

Smoking affects both the inside and outside of the body; some of these effects are immediate and others can occur later in a smoker's life. Some of the long term effects of smoking are:

• Blindness
• Infertility and impotence
• Stroke
• Cardiovascular disease and other diseases of the arteries
• Gangrene, often resulting in the loss of limbs
• Various cancers, especially lung cancer
• Less oxygen to the brain and heart
• Shortness of breath
• Increased blood pressure
• Gum disease
• Smelly breath and stained teeth

Tobacco Cancer

Smoking causes cancer of the lung, oral cavity, pharynx, larynx, esophagus, pancreas, kidney, bladder and cervix. Recent evidence links smoking with cancer of large intestine and some forms of leukemia.

Most deaths from lung cancer are caused by smoking

Although other factors can cause lung cancer, smoking is responsible for 85% of all new cases of lung cancer in Canada.

Lung cancer is a highly lethal disease; only a small minority of patients are alive five years after diagnosis.

The causal relationship between smoking and cancers of the mouth, pharynx, larynx, and esophagus has been established for many years. Smokeless tobacco also causes cancer of the mouth.

Like all tobacco-caused diseases, the risk increases with amount and duration of smoking. Alcohol consumption is also a risk factor for these cancers, and the combination of alcohol consumption and smoking results in a greatly increased risk.

Recent studies confirm earlier findings of a strong link between smoking and cancer of the pancreas and with cancer of the kidney and bladder.

Recent findings also suggest that smoking may be a previously unrecognized cause of cancer of the large intestine (colorectal cancer) in both men and women. Evidence is also growing concerning a link between smoking and some forms of leukemia.