Adhering to a Mediterranean diet was associated with higher 2-year cognitive function among middle-aged and older Puerto Rican adults with type 2 diabetes, according to study results published in Diabetes Care.
In this observational study, investigators utilized data from the longitudinal Boston Puerto Rican Health Study, which looked at diet, psychosocial factors, and health among Puerto Rican adults at a baseline visit between 2004 to 2007 and follow-up visit at 2 and 5 years (n = 913).
Traditional foods and beverages habitually consumed by Puerto Ricans were assessed using a validated food frequency questionnaire using portions and foods appropriate for this population. The Mediterranean diet score (MeDS) measured adherence to 9 dietary components. Components of meat, meat products, dairy, and dairy products were reverse coded. Total MeDS ranged from 0 (low adherence) to 9 (high adherence).
Cognitive function was assessed using a comprehensive battery of 7 neuropsychological examinations administered by a neuropsychiatrist-trained research assistant, including the mini mental state examination, 16-word list learning test, Stroop test, digit span forward and backward test, verbal fluency, clock drawing, and figure copying. Global cognitive function score was calculated by averaging the z scores for each of the 10 cognitive scores generated.
At baseline, 74.2% of participants were not under glycemic control and 67.9% had poor or declined glycated hemoglobin values. In participants with type 2 diabetes, higher MeDS was significantly associated with higher 2-year change in score of global cognitive function (0.027 ± 0.011; P =.016), mini mental state examination (0.156 ± 0.072; P =.031), word recognition (0.365 ± 0.152; P =.017), digit span forward (0.106 ± 0.046; P =.023), and clock drawing (0.066 ± 0.028; P =.022), but not significantly associated with the other cognitive tests.
This study is prone to limitations inherent in observational studies. Residual confounding factors were not assessed in these models.
Glycemic control further sustained the benefits of the Mediterranean diet in participants with type 2 diabetes, suggesting that both the diet and effective diabetes management may help to preserve cognitive function.
Mattei J, Bigornia SJ, Sotos-Prieto M, Scott T, Gao X, Tucker KL. The Mediterranean diet and 2-year change in cognitive function by status of type 2 diabetes and glycemic control [published online May 23, 2019]. Diabetes Care. doi:10.2337/dc19-0130