Clinicians, medical and public health researchers, and communication scholars alike have long been concerned about the effects of conflicting health messages in the broader public information environment. Not only have these messages been referred to in many ways (e.g., “competing,” “contradictory,” “inconsistent,” “mixed,” “divergent”), but they have been conceptualized in distinct ways as well—perhaps because they have been the subject of study across health, science, and political communication domains. Regardless of specific terminology and definitions, the concerns have been consistent throughout: conflicting health messages exist in the broader environment, they are noticed by the public, and they impact public understanding and health behavior. Yet until recently, the scientific evidence base to substantiate these concerns has been remarkably thin. In the past few years, there has been a growing body of rigorous empirical research documenting the prevalence of conflicting health messages in the media environment. There is also increasing evidence that people perceive conflict and controversy about several health topics, including nutrition and cancer screening. Although historically most studies have stopped short of systematically capturing exposure to conflicting health messages—which is the all-important first step in demonstrating effects—there have been some recent efforts here. Taken together, a set of qualitative (focus group) and quantitative (observational survey and experimental) studies, guided by diverse theoretical frameworks, now provides compelling evidence that there are adverse outcomes of exposure to conflicting health information. The origins of such information vary, but understanding epidemiology and the nature of scientific discovery—as well as how science and health news is produced and understood by the public—helps to shed light on how conflicting health messages arise. As evidence of the effects of conflicting messages accumulates, it is important to consider not just the implications of such messages for health and risk communication, but also whether and how we can intervene to address the effects of exposure to message conflict.
