The Effect of Mediterranean Diet Adherence on the Relationship between Cognitive Performance and Cancer Survivorship

Purpose: 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 cross-sectional data from the 2011-2012 and 2013-2014 cycles of the National Health and Nutrition Examination Survey. 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). Cognition was assessed via: (1) the Digit Symbol Substitution test assessing processing speed, attention, and working memory, (2) the Consortium to Establish a Registry for Alzheimer’s disease (CERAD) assessing learning and short-term memory, and (3) the Animal Fluency test assessing executive function. Linear regression models adjusted for age, race, gender, comorbidities, smoking, total kilocalories, day and time of year of recall. Results: Among 2,450 participants, 385 had cancer. Mean age was 68.9 years (SE=0.2). The most common cancer was breast cancer (24%). The average aMed score was 3.5 (SE=0.1) in survivors versus 3.6 (SE= 0.1) in non-cancer controls. Cancer history was not associated with cognition (p>0.05). Among high aMed scores, cancer history was more negatively associated with animal fluency compared to low aMed scores ( (95% CI): -1.11 (-2.33, 0.12), p=0.08 for aMed*Cancer interaction term). Conclusions: Among high versus low aMed scores, positive cancer history was more negatively associated with cognition. Prospective studies are needed to confirm these results.