Quit smoking, don't just cut back, to prevent early death: study

Last Updated: Tuesday, November 28, 2006 | 11:22 AM ET

CBC News

Even reducing cigarette use by half doesn't cut the risk of premature death, according to an international study released Tuesday. 

The results run counter to the advice many doctors give smokers — curtail smoking to live longer. 

'Cutting back is helpful if it is going to get you to the next step of quitting altogether.'- Dr. Charlie Butts, Alberta Cancer Board

Dr. Kjell Bjartveit, former director of the National Health Screening Service in Oslo, and his colleagues followed 51,000 men and women in Norway for 20 years to track how quitting changes death totals from heart disease, lung cancer and other tobacco-related cancers.

Participants were between 20 and 34 years old when the study began. Their risk of developing cardiovascular disease was assessed at the start of the study and then twice during the 20 years of followup.

The participants were classified as:

• Never smokers.
• Ex-smokers.
• Quitters, who gave up between the first and second check.
• Moderate smokers having one to 14 cigarettes daily.
• Reducers who had more than 15 cigarettes a day, but who halved the number smoked by the second check.
• Heavy smokers lighting up more than 15 cigarettes a day.

"Long-term followup provides no evidence that heavy smokers who cut down their daily cigarette consumption by more than 50 per cent reduce their risk of premature death significantly," the team concluded in Tobacco Control, published by the British Medical Association.

"In health education and patient counselling, it may give people false expectations to advise that reduction in consumption is associated with reduction in harm."

Every year, 45,000 Canadians die from smoking-related illness.

The Norwegian research has found cutting back is only helpful as a step on the path to quitting.

"So the message should be that cutting back is helpful if it's going to get you to the next step of quitting altogether," said Dr. Charlie Butts, an oncologist with the Alberta Cancer Board.

"But don't fool yourself in thinking, 'if I cut from a pack to half a pack I'm doing myself a great deal of good.'"

Advocate nicotine replacements

Susan Ferguson of Edmonton quickly puffs a cigarette as she huddles in a doorway downtown, hiding from the biting wind in –30 C weather.

"I've cut back a lot," said Ferguson. "I've cut back from a pack-and-a-half to half a pack a day, so I'm getting there."

People who reduce smoking tend to compensate by puffing harder and faster on the cigarettes they do smoke to get more nicotine, said Roberta Ferrence, a smoking cessation researcher in Toronto.

The best route to quitting seems to be nicotine replacements such as the patch, nicotine gum and medications, Ferrence said.

Butts said the good news in the research is that many diseases can be avoided by quitting.