The health hazards of smoking cessation.

The health hazards of smoking cessation.

The health hazards of smoking cessation.

Health and medicine explained.
Oct. 13 2005 11:57 AM

Smoke-Free and Fat

The health hazards of kicking the habit.

Illustration by Mark Alan Stamaty. Click image to expand.





How good is the evidence linking smoking cessation to weight gain? In 1991, the CDC published an article titled "Smoking Cessation and Severity of Weight Gain" in the New England Journal of Medicine. The researchers used data from a national health survey and concluded that "major weight gain is strongly related to smoking cessation, but occurs only in a minority of those who stop smoking." About 10 percent of men and women were found to have experienced "major" weight gain (at least 30 pounds).

That surely isn't enough to power an epidemic. But hidden in the tables, where the most interesting data always lurk, is a more disturbing fact: In the subgroup of former smokers who had stopped for longer than one year (the real quitters), more than 22 percent had gained at least 17 pounds. That's more than a spare tire. It's enough to push former smokers across the body mass index chart toward official obesity.

For several years, few investigators followed up on these findings, perhaps for fear that pointing out the connection between quitting smoking and gaining weight might be viewed as pro-cigarette. Then this spring, a large study from Europe looked at the net effect on lung function of stopping smoking (good) and concomitant weight gain (bad). The authors concluded that, alas, weight gain was almost as deleterious to the lungs as smoking cessation was beneficial. It's hard to breathe with a weighted-down chest.


To be sure, the final statistical analysis (of various technical measures of breathing capacity) showed that lungs are better off without cigarette smoke, despite the weight gain. And the study didn't take into account other smoking-related problems, such as atherosclerosis and lung cancer, that might have further tipped the cost-benefit scales toward the quitters.

Still, the study served to remind us that smoking cessation is not an unadulterated victory for public health. Over the last two decades, the proportion of smoking adults in the United States has declined from 32 percent to 22 percent. (Right now, there are 45 million smokers and an equal number who have quit.) Meanwhile, during the same period of time, the prevalence of adult obesity—figure at least 25 extra pounds on a normal frame—has risen: from 15 percent (1976 to 1980) to 23 percent (1988 to 1994) to 30.5 percent (1999 to 2002). We can't know for sure whether these two trends are linked by anything beyond coincidence, and it's worth noting that the rise in obesity correlates with the aging of the baby-boomer population. But a causal relationship certainly is biologically plausible.

Is smoking a temporary crutch for people who would be otherwise fated to be overweight, so that when they stop smoking, they simply realize their BMI manifest destiny? This too is difficult to know. In a 1995 article, researchers looked at weight gained across a 10-year span among three groups: never-smokers, current smokers, and quitters. Current smokers were easily the thinnest group. They are followed by the never-smokers. The quitters, on the other hand, were more than twice as likely to have become overweight than the never-smokers—and far worse off, weight-wise, than those who continued to smoke.

If the choice is between smoking and obesity, which is worse for public health? For now, smoking wins hands down. Cigarettes kill about 400,000 people annually and cost $150 billion a year—half in medical costs and half in lost productivity. In contrast, medical expenditures that can be attributed to obesity were estimated at $75 billion in 2003. But obesity may not be cheaper for long. A recent study of more than 4,000 white adults followed for 30 years found that nine out of 10 men and seven of 10 women became overweight by the time they turned 60. The Rand Corporation predicts that in the year 2020 (when all the baby boomers will be mighty old), health-care costs for obesity-related conditions will rise to account for 20 percent of the total amount Americans spend on health care. The projected increase in obesity would offset decreases in the rates of other chronic conditions, resulting in a net increase in the overall disability rate.


So, after all of these years of vilification, should doctors tell patients at risk for obesity to light up? Is it possible that cigarettes do more good than harm?

Please. The trail of misery, illness, and death etched by cigarettes remains unparalleled in the history of mankind. That part's simple.

What isn't simple is what to do next. A proposal: The link between obesity and not smoking is another reason for the Food and Drug Administration to regulate tobacco, as the agency never has, despite all those surgeon general's warnings. It defies belief that, in 2005, tobacco companies are not required to specify what they put in their product. If scientists knew exactly what cigarettes consist of, they could ferret out what might be contributing to weight control. Is it the nicotine itself, which has been shown to suppress appetite (though nicotine patches don't seem to work too well)? Is it simply sucking on something all day? Or something else altogether?

Were the tobacco industry to help answer these questions, it could (maybe) start to redeem itself for decades of public-health abuse. Imagine—the industry could announce that stopping the epidemic of obesity is its new goal. I suspect, however, that the tobacco companies will keep their products in the shadows, away from scientific inquiry. They'll stick with their plans to addict Asia, Africa, and beyond. And Americans will get ever fatter.