Mediterranean diet, improved glycemic control provide combined cognitive benefits
Adults with type 2 diabetes may be able to improvements their cognitive abilities by incorporating a Mediterranean diet into their regular disease management regimens, according to findings published in Diabetes Care.
“Consuming foods and nutrients characteristic of the Mediterranean dietary patternhas been consistently associated with better cognitive function among adults and older adults,” Josiemer Mattei, PhD, MS, MPH, assistant professor of nutrition in the department of nutrition at the Harvard T.H. Chan School of Public Health, and colleagues wrote. “As consuming a Mediterranean diet has been associated with prevention and control of type 2 diabetes, this dietary pattern may have dual benefits for both type 2 diabetes and cognition.”
Mattei and colleagues conducted an observational study with 465 adults with type 2 diabetes (mean age, 58.9 years; 72.5% women) and 711 adults without the condition (mean age, 56 years; 73.6% women) who were recruited for the Boston Puerto Rican Health Study between 2004 and 2007.
Along with Mediterranean diet adherence, the researchers also assessed adherence to the Healthy Eating Index, Alternate Healthy Eating Index and Dietary Approaches to Stop Hypertension (DASH) diets using food questionnaires at baseline and at 2 years. Superior adherence to each of the four diets was implied by higher scores. Seven neuropsychological examinations were also conducted with each participant to evaluate different aspects of cognitive ability.
Participants who had an HbA1c level of 7% or more at baseline were considered to have uncontrolled hyperglycemia, and those with lower measures were considered to have glycemic control. If participants lowered their HbA1c by at least 0.5% after 2 years, they were considered to have “stable or improved” glycemic control, whereas HbA1c increases of more than 0.5% equated to “poor or declined” glycemic control.
The researchers observed an association between greater adherence to a Mediterranean diet and superior overall cognitive function (P = .016) for those with type 2 diabetes at 2 years compared with baseline even when adjusting for age and sex. However, this was only true when participants had HbA1c of less than 7% at baseline (0.062; P = .004) or stable or improved glycemic measures after 2 years (0.053; P = .007), with the association losing its significance when participants had poor or declining glycemic control.
At 2 years, memory function improved for those without type 2 diabetes who adhered to the Mediterranean diet compared with baseline (P = .016), but there was not a significant association with overall cognitive ability. In addition, the researchers noted that the other three diets had memory function benefits but were “inconsistent” in terms of improving overall cognitive function.
“Our findings suggest that the Mediterranean diet benefits cognition among both individuals without type 2 diabetes and patients with type 2 diabetes, with the latter obtaining the most benefits,” the researchers wrote. “Furthermore, being under glycemic control (vs. uncontrolled) seems to amplify the benefits, which may explain null results in other studies if participants had uncontrolled diabetes.” – by Phil Neuffer