The effect of Mediterranean Diet adherence on the relationship between cognitive performance and cancer survivorship

Up to 75% of cancer survivors experience cognitive impairment from cancer or its treatment. No modifiable risk factor has been identified; however, a Mediterranean Diet may be protective. We sought to determine if the relationship between cognitive performance and cancer survivorship depends on Mediterranean Diet adherence.

We used the latest data from the National Health and Nutrition Examination Survey (NHANES). Mediterranean Diet adherence was defined as the aMed score which gives 1 point for intake above/below the sample-specific median for healthful/unhealthful food groups (range 0-9). Cognitive processes assessed included processing speed, attention, working memory, learning, short-term memory, and executive function. Linear regression models adjusting for demographics, diet, and health behavior were used to determine the relationship between cognition and cancer history.

Among 2450 participants, 385 had cancer. Mean age was 68.9 years (SE = 0.2). The most common cancer was breast cancer (24%). Cancer history was not associated with cognition (p > 0.05). Among high aMed scores, cancer history was more negatively associated with number of Intrusions compared to low aMed scores (β (95% CI): 0.61 (0.07, 1.16), p = 0.03 for aMed*Cancer interaction term).

Cancer history was more negatively associated with cognition among high versus low aMed scores. Because of the cross-sectional nature of NHANES, the limited number of cancer survivors, and the lack of treatment information, larger prospective studies with treatment data are needed.

Cancer survivors may require dietary recommendations different from that of the general population. More studies, however, are needed to confirm this.