Smoking May Kill at Least Half
Of Those Who Start Habit Young

LONDON -- At least half of the people who begin smoking in their youth, and perhaps as many as two-thirds, are eventually killed by the habit, according to a mammoth 50-year medical study by British researchers.

The report in the British Medical Journal is the second part of a study that began in 1951. The publication's first report on the study in June 1954 was considered a landmark, confirming the link between smoking and lung cancer. The second part of the study tracked the same participants for the past 50 years and highlights the findings that kicking the habit can add years to the lives of former smokers.

Researchers Sir Richard Doll and Sir Bradford Hill -- the same two scientists who published the 1954 report -- said that, on average, cigarette smokers die about 10 years younger than nonsmokers. The main tobacco-related causes of death included lung cancer; heart disease; cancers of the mouth, pharynx, larynx and esophagus, and other respiratory diseases.

Those who stopped smoking at the age of 60 gained three years of life, those who quit at 50 gained six years and those who stopped smoking at 40 gained nine years of life expectancy, the report said. For those who kick the habit at 30 the increased risk was avoided almost totally, the researchers said.

"Over the past few decades, prevention and better treatment of disease have halved nonsmoker death rates in the elderly in Britain," said Sir Richard, emeritus professor of medicine at the Clinical Trial Service Unit at Oxford University, who is now in his 90s. "But these improvements have been completely nullified by the rapidly increasing hazards of tobacco for those who continue to smoke cigarettes," he added.

The study, funded by the Medical Research Council, Cancer Research U.K. and the British Heart Foundation, followed almost 35,000 male doctors born in 1900 to 1930.

Copyright © 2004 Associated Press