Nicotine and Obesity: Filtering the Data

Individually, both nicotine and obesity are challenging subjects where bias creeps in from strongly held views. When they come together, the challenge is compounded. A new analysis published by the National Bureau of Economic Research reminds us that the challenge is unavoidable because significant weight gain is one of the consequences of quitting smoking — even though that risk is clearly outweighed by the health benefits of quitting.

Using data from more than 5,000 subjects in the Lung Health Study, Charles Courtemanche and colleagues found that the average long-term weight gain that results from quitting is about 10 pounds or 1.5 BMI units. Unfortunately, the effect does not appear to fade with time and the effect appears to be greatest for younger people, females, people without a college degree, and people with a BMI below 25 before they quit. They conclude that the decline in smoking has likely contributed to about 14% of the excess in obesity that has accumulated over the last few decades.

This is a tough subject for experts to tackle, but dodging the issue doesn’t help. People know it happens and for those people who have resisted quitting, especially women, concern about weight gain is a pretty significant barrier.

Evidence-based guidelines on this issue are clear. Nicotine replacement can delay or prevent some of that weight gain. Clinicians should address the issue with people up front, advising people of their options.

But bias about nicotine gets in the way of clear messaging. Despite the fact that most of the harm from smoking comes from the smoke — not the nicotine — moral judgements about continued use of nicotine creates barriers to reducing the harm of tobacco and smoke. In a recent commentary, Lynn Kozlowski observed:

When there is a “contamination of the pure” (by recommending e-cigarettes which are not perfectly safe), disgust can be felt. When individual rights are violated (harm, unfairness), anger arises. The interplay of the moral emotions of disgust, contempt and anger contribute to individual positions on harm reduction issues.

The puritan impulse is strong. And so, some public health authorities are making a great effort to persuade the public that reduced-harm nicotine products, such as electronic cigarettes, are an immoral health hazard.

The result? Many smokers will stick with the devil they know: cigarettes. Tobacco harm reduction remains a lost opportunity because objective information about it is filtered through moral judgements about nicotine.

For people frustrated about barriers to accessing evidence-based obesity care, this story is way too familiar.

Click here for the NBER paper on smoking and obesity. Click here for more about muddled messaging around the subject of tobacco harm reduction.

Smoke, photograph © Drew Brayshaw / flickr

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February 18, 2016