You may have heard the anti-supplement crowd crowing about recent studies showing that smokers smoke more after taking vitamins. But that’s a total misinterpretation of the true research findings. The real deal…

Previous studies have demonstrated a psychological phenomenon called the licensing effect, whereby people subconsciously and/or consciously view the benefits of one type of virtuous behavior as a justification for or counterbalance to some negative behavior. In other words, people fool themselves into believing that a healthful action cancels out a harmful one.

The new research, led by Wen-Bin Chiou, PhD, at National Sun Yat-Sen University in Taiwan, included two similar studies of smokers. All smokers were given placebos—but half were told that they had received a vitamin C pill or a multivitamin, while the other half knew they had received a placebo. Participants then completed one-hour surveys during which they were allowed to smoke. Both surveys included questions that (unbeknownst to participants) gauged smokers’ perceptions of their own invulnerability… the second study’s survey also gauged participants’ attitudes toward supplements. Results: Smokers who believed that they had taken vitamins had greater feelings of invulnerability and smoked more cigarettes during the survey than smokers who knew they had received placebos… and the more strongly a participant believed in the health benefits of supplements, the more he or she was likely to smoke.

Bottom line: Taking vitamins does not in and of itself make a person smoke more, but care must be taken to avoid an illusion of invulnerability that encourages greater recklessness with regard to smoking. Dr. Chiou said, “We never suggested that smokers should not take dietary supplements—if smokers want to take supplements, they should.” The licensing effect may disappear, he added, if smokers remind themselves that their primary goal is good health and not wrongly presume that taking supplements (or eating broccoli or running marathons, for that matter!) could prevent lung cancer or otherwise offset the hazards of smoking.