Relationship between fruit and vegetable intake and interference control in breast cancer survivors

Purpose Nutrition plays an important role in brain structure and function, and the effects of diet may even be greater in those at greater risk of cognitive decline, such as individuals with cancer-related cognitive impairment. However, the relation of dietary components to cognitive function in cancer survivors is unknown. The objective of this study was to determine whether breast cancer survivors (BCS) evidenced impairments in interference control, a component of cognitive control, compared to age-matched women with no prior history of cancer, and to examine the moderating role of diet on cognitive function. Methods In this cross-sectional study, a modified flanker task was used to assess interference control in BCS (n = 31) and age-matched women with no prior history of cancer (n = 30). Diet was assessed with 3-day food records. Differences between BCS and age-matched controls were assessed using linear mixed models, and multilevel regression analyses were conducted to assess the moderating role of diet on cognitive performance. Results Cognitive performance was not different between groups. Fruit intake and vegetable intake were significantly associated with better performance on the incompatible condition of the flanker task (i.e., shorter reaction time and increased accuracy), independent of disease status. The association between dietary components and cognition was stronger for the incompatible incongruent condition, suggesting that fruit and vegetables may be important for the up-regulation of cognitive control when faced with higher cognitive demands. Conclusions There was no difference in performance on an interference control task between BCS and age-matched controls. The data suggest that greater fruit intake and vegetable intake were positively associated with interference control in both BCS and age-matched controls.