Smokers under 55 who quit the habit revert to normal heart attack risk much more quickly than scientists have thought, but people who insist on continuing to smoke--justifying their decisions by switching to low-yield cigarettes--are playing a deadly game with their own health.
Moreover, the prospect of suffering a heart attack can decline even in smokers who have other conditions that add to their heart attack risk. For smokers who have developed high blood pressure or who have family histories of heart attack susceptibility, quitting can bring about a significant diminution of the prospect of having a sudden heart seizure.
Two New Studies
That is the substance of two new studies on smoking and health that apparently add to the growing body of scientific evidence that there simply is no good news for people who insist on using tobacco and perhaps more good news than researchers have believed possible for people who quit.
For quitters under 55, the good news is that the risk of sudden major heart attack--risk that is substantially elevated by smoking--returns to normal within perhaps as little as two years or less after the last cigarette is smoked.
Researchers who did the study at the Boston University School of Public Health cautioned that the reversal is probably not that fast for all smokers. But they said the new evidence not only confirms the ability of the body to rebound from the effects of even decades of smoking--a capability established in earlier research--but implies there is a faster response than many scientists may previously have thought possible.
The study, published last week in the New England Journal of Medicine, focused on men, but researcher Lynn Rosenberg, who headed the Boston project, said in a telephone interview the
Rosenberg said a small group of women was originally included in the newly published project but that, though the women showed the same reversal effect as men, the number of female subjects was too small for statistical review as precise as that to which male subjects were subjected.
For smokers who can't or won't discontinue their addictions, however, a study at the University of Arizona Health Sciences Center in Tucson finds that--especially among long-time smokers--it does little or no good to change from conventional cigarettes to so-called low-yield ones. The research is being published in this month's issue of the journal Chest.
Even though what tobacco company marketing departments call "light" cigarettes produce less tar and nicotine than conventional products, people with smoking histories lasting several years or more have probably sustained such extensive impairment of their lungs that using the low-yield brands won't improve their health, at all, the study concluded.
Earlier studies established that people who quit entirely can return to normal or near-normal lung function within about three years after they stop smoking. Their risks of lung cancer may remain, but they will find breathing easier and be less prone to other lung diseases.
A 'Deadly Delusion'
The Arizona study continued a long-standing debate over whether it is even possible to produce a "safe" cigarette--a proposition attacked earlier this year in still a third scientific publication, the New York State Journal of Medicine, as "a deadly delusion."
Attempts to reduce the noxiousness of cigarette smoke and its components trace to the early 1970s. Marketing figures indicate that so-called low-yield cigarettes now account for significantly more than half the total market for cigarette products.
In the Boston study, Rosenberg and her colleagues examined the relationship of smoking behavior and heart attack risk in a total of nearly 5,000 men--all under 55. They were identified from among patients at 78 hospitals in Massachusetts, Rhode Island, Connecticut and New York.
The study examined the smoking and health histories of 1,873 men who had suffered heart attacks and a control group of another 2,775 men who were selected at random but who had no heart attack history. All the subjects were between 20 and 54 years old. Men smoking at the time of the research were found to have triple the risk of sudden catastrophic heart attack as the controls who had never smoked. Men who had been off tobacco for at least one year had declined to double the risk and for men who had abstained for 23 months, the risk dropped to nearly the same level as the men who had never smoked.
Back to Normal Levels
The risk level is probably not equal to the never-smokers, Rosenberg said, but by two years after smoking cessation, the chance of having a sudden heart attack has returned to almost normal levels. Previous studies indicated that, after 20 years or so, heart attack rates for smokers who quit may be the same as for never-smokers.