Dietary Intervention for Cognitive and Cardiometabolic Health in Elderly

The MedLey study was a dietitian-led, randomized, controlled, parallel dietary intervention trial comparing the effect of a traditional MedDiet with a habitual diet on cognitive and cardiometabolic health outcomes in a healthy elderly population. The protocol has been described elsewhere [17 ,18 (link)]. In brief, 152 healthy Australian men and women aged 65 years and above were recruited and randomly allocated to either a MedDiet or a habitual diet (HabDiet, control) for 6 months. A total of 137 participants completed the study (MedDiet n = 74, HabDiet n = 63). Outcome measures included blood pressure, anthropometry (BMI, body weight, abdominal adiposity as measured by dual energy X-ray absorptiometry (DEXA)), waist/hip ratio (WHR), endothelial function, F₂-isoprostanes (F₂-IsoP), inflammatory biomarkers, lipids, glucose, insulin, dietary compliance, and cognitive performance and were collected at baseline and at 3 and 6 months of the intervention. Participants attended fortnightly sessions with a study dietitian to ensure adherence was maintained. Dietary intake was assessed with a 3-day weighed food record (WFR) and a food frequency questionnaire (FFQ) [19 (link)] at baseline and then during each intervention phase at 2 months and 4 months. The MedDiet was based on the traditional Cretan MedDiet [20 (link)] and was rich in fruits, vegetables, extra virgin olive oil, legumes, nuts, grains, and cereals, with lower amounts of red meat, processed foods, and discretionary foods. WFR data were analysed using FoodWorks Professional software (Version 7.0.3016; Xyris Software) to generate grams and servings per day of foods and food groups [17 ]. These data were used to determine adherence to the dietary prescription and the calculation of DII and E-DII scores. The study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving human participants were approved by the Human Research Ethics Committee (22 June 2013, #31163), University of South Australia, Adelaide, Australia. Written informed consent was obtained from all participants before commencement. This trial was registered with the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au (accessed on 8 December 2022)) as ACTRN12613000602729.