Sex Differences in How Cancer Beliefs and Health-Related Confidence Are Associated with Fruit and Vegetable Consumption

Introduction: Adequate fruit and vegetable (FV) consumption is promoted by public health agencies as a means of preventing several chronic conditions, such as cardiovascular disease and cancer. This study investigated whether two potential psychological barriers, fatalistic beliefs about cancer (beliefs that cancer is predetermined and not under one’s control) and health-related confidence, were associated with FV consumption. Because there are sex differences in beliefs, confidence, and FV consumption, we also examined whether sex moderated these associations.

Methods: Analyses were conducted using data from the five most recent waves (spanning 2011 to 2017) of the Health Information National Trends Survey, a nationally representative population survey (N=16,965). At each wave, participants reported daily levels of FV consumption (2 items), cancer fatalism beliefs (3 items: “cancer prevention is not possible;” “there are too many recommendations for preventing cancer;” “everything causes cancer”) and confidence in the ability to care for one’s health (1 item). Weighted linear regression adjusting for participant characteristics and health status assessed the relations of fatalism and confidence with FV consumption, as well as whether sex moderated these associations. Significant interactions were probed by examining the simple slopes for men and women.

Results: Health-related confidence was positively associated with FV consumption, b=0.34, p < .001, whereas two of three cancer beliefs (“too many recommendations” and “cancer prevention is not possible”) were negatively associated with FV consumption, ps <.001. Sex moderated the associations between these factors and FV consumption, ps < .05. Fatalistic beliefs were more strongly associated with eating fewer servings of fruits and vegetables for men, bs < -0.31, ps < .001, than women, bs < -.0.14, ps < .01. In contrast, health-related confidence was a stronger predictor of FV consumption for women, b= 0.43, p < .001, than men, b = 0.26, p < .001.

Conclusion: Fatalistic beliefs about cancer are stronger predictors of FV consumption for men than women, whereas health-related confidence is a stronger predictor of FV consumption for women. These findings extend the evidence that fatalism and health-related confidence are associated with health promoting behaviors, by elucidating gender differences in the strength of their associations with FV consumption. This evidence may inform health communication efforts; tailoring messaging to leverage sex-specific barriers may improve their effectiveness.