Ironic Effects of Dietary Supplementation

Chiou, W.-B., Yang, C.-C., & Wan, C.-S. (2011). Ironic effects of dietary supplementation: Illusory invulnerability created by taking dietary supplements licenses health-risk behaviors. Psychological Science, 22(8), 1081-1086.

One might expect that the increased availability of dietary supplements would result in improvements in public health. Chiou, Yang, and Wan (2011) suggested that the opposite might occur. They hypothesized that taking a dietary supplement might increase one’s sense of invulnerability and thus lead to taking greater health risks. Eighty-two Taiwanese participants were asked to evaluate a daily supplement that was either identified as a multivitamin or a placebo (all were, in fact, placebo pills). Participants were also given a survey measuring invulnerability and a series of health related behaviors. In addition, they were given two meal options (a buffet or an organic lunch) and two options for testing a pedometer (a shorter route or a longer route). As hypothesized, compared with the placebo group, the participants in the vitamin condition expressed higher levels of invulnerability, greater preference for unhealthy activities in their questionnaire responses, and were more likely to select the less healthy options, including eating the buffet and walking the shorter distance.

Making Connections

Health-risk behaviors
Perceived invulnerability

Media Supplement

Additional research by Wen-Bin Chiou and colleagues suggests that the sense of invulnerability associated with taking a daily supplement may also increase cigarette smoking.