Cigarette smokers die on average 10 years earlier than nonsmokers, but kicking the habit, even at 50 years of age, can halve the risk, according to half a century of research reported on Tuesday. Findings from a 50-year study into the dangers of smoking showed that if people quit by the age of 30 they can avoid nearly all of the risk of dying prematurely. "Cigarette smoking reduces the expectation of life by 10 years," said 91-year-old Oxford University professor Richard Doll, who discovered the link between cancer and smoking. "It is clear that consistent cigarette smoking doubles mortality throughout adult life--middle and old age. It is also clear that giving up smoking can eliminate a very large part of the hazard." The study's findings are particularly important to gay men and lesbians because some studies have shown that they are twice as likely to smoke as their age-matched heterosexual peers.
Doll and Bradford Hill confirmed the link between smoking and lung cancer in a landmark study published in the British Medical Journal on June 26, 1954. Half a century later, Doll and Oxford University professor Richard Peto have reported the 50-year results from the same study of 34,439 British doctors in the journal. "This study is a remarkable achievement. Studies that last 50 years are highly unusual in medicine, and it's even more unusual for one to have an author who was there at the beginning and after 50 years," the journal's editor told a news conference.
The early results from Doll's second study confirmed that smoking causes lung cancer and suggested that it also causes heart disease. "We thought we'd better carry the study on for a lot longer and see if smoking causes anything else, and, by goodness, it does," said Doll. "By the time we did the 40-year follow-up we found there were some 25 diseases which smoking seemed to cause and that the mortality was about double with the consistency of smoking." Fifty-year results showed that among men born in the 1920s who became persistent smokers, about two thirds died from their habit. Since Doll began the study five decades ago, tobacco has already killed about 100 million people worldwide. During the present century there will be about 1 billion tobacco deaths if current smoking patterns continue. (Reuters)