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

Background/objectives: 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.

Methods: 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.

Results: 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).

Conclusions: 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.

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