Even Light Smoking Ups Lung Cancer, Heart Disease Risk

Smoking just a few daily cigarettes raises the risk of dying of heart disease, lung cancer, and from any cause, according to a Norwegian study.

The study appears in Tobacco Control. The researchers included Kjell Bjartveit of the National Health Screening Service in Norway’s capital, Oslo.

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Heart Deaths Tripled

Heart disease deaths were nearly three times as common among light smokers as among nonsmokers. The risk was a bit higher for women than men, the study shows.

The study included more than 42,000 adults in Oslo and three mainly rural Norwegian counties.

In the U.S., heart disease is a leading cause of death among men and women. Smoking is widely viewed as a risk factor for a host of health problems, including heart disease and several cancers.

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Higher Cancer, Death Risk

Lung cancer deaths were also more common among the study’s light smokers. Light smokers puffed one to four cigarettes daily.

Men who were light smokers were nearly three times as likely to die of lung cancer, compared with nonsmokers.

The lung cancer risk was even bigger for women who were light smokers. They were five times as likely as nonsmokers to get lung cancer, the researchers report.

More light smokers than nonsmokers also died of any cause during the study, which stretched from the mid-1970s to 2002.

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Changing Habits?

When the study started, participants were screened for heart disease and noted whether they smoked. Their health was followed for nearly 30 years.

Thirty years is a long time -- long enough for some people to quit smoking and others to start.

Ten years after the study started, some nonsmokers reported that they had become smokers. A large proportion of “light” smokers had also changed their habits. Roughly equal numbers of light smokers had increased or cut down on daily cigarettes.

It’s hard to know exactly how those changes affected the results, write the researchers. However, they note “no strong reason” to believe that light smokers’ results were substantially biased.

The health risks of light smoking should be emphasized more strongly, write Bjartveit and colleagues.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Bjartveit, K. Tobacco Control, Sept. 22, 2005; vol 14: pp 315-320. News release, BMJ Specialist Journals.