A randomized experiment to examine unintended consequences of dietary supplement use among daily smokers: taking supplements reduces self-regulation of smoking
Version of Record online: 2 AUG 2011
© 2011 The Authors, Addiction © 2011 Society for the Study of Addiction
Volume 106, Issue 12, pages 2221–2228, December 2011
How to Cite
Chiou, W.-B., Wan, C.-S., Wu, W.-H. and Lee, K.-T. (2011), A randomized experiment to examine unintended consequences of dietary supplement use among daily smokers: taking supplements reduces self-regulation of smoking. Addiction, 106: 2221–2228. doi: 10.1111/j.1360-0443.2011.03545.x
- Issue online: 3 NOV 2011
- Version of Record online: 2 AUG 2011
- Submitted 8 February 2011; initial review completed 27 April 2011; final version accepted 10 June 2011
- Attitudes towards dietary supplements;
Aims We examined whether smokers' use of dietary supplements (e.g. vitamin C, multi-vitamins) induces illusory invulnerability that in turn disinhibits smoking. Such supplement use may be perceived as conferring health credentials.
Design A single-factor (credentials: with or without) between-subjects design was employed. Smokers were assigned randomly to take either a known placebo pill or a dietary supplement (in fact, the same placebo) in an ostensible health-food test.
Setting Laboratory at Kaohsiung Medical University, Taiwan.
Participants Study 1 involved of a student sample consisting of 74 daily smokers, whereas study 2 involved a community sample consisting of 80 daily smokers.
Measurements In Study 1, participants reported their perceived invulnerability following the manipulation. In study 2, pre- and post-test measures of invulnerability were administered, and attitudes towards dietary supplements were assessed prior to the manipulation. In both studies, the dependent measure was the number of cigarettes smoked during completion of an unrelated survey.
Findings Participants who believed that they were taking a dietary supplement smoked more cigarettes than did controls. Study 1 found support for the role of perceived invulnerability as a mechanism underlying this effect. Study 2 demonstrated the moderating effect played by attitudes towards dietary supplements: a more positive attitude towards supplements increased susceptibility to licensing effects.
Conclusions Dietary supplement use may create illusory invulnerability, reducing the self-regulation of smoking. Reminding health-conscious smokers that multi-vitamins do not prevent cancer may help such smokers to control their smoking and encourage them to stop.