Five RCTs of the Mediterranean diet and cognition have been published to date. The data are mostly nonsignificant, with small ESs. However, the significant improvements in cognitive domain composites in the most robustly designed study warrant additional research.

Background: Maintain Your Brain (MYB) is a randomized controlled trial of an online multi-modal lifestyle intervention targeting modifiable dementia risk factors with its primary aim being to reduce cognitive decline in an older age cohort. Methods: MYB aims to recruit 8,500 non-demented community dwelling 55 to 77 year olds from the Sax Institute's 45 and Up Study in New South Wales, Australia. Participants will be screened for risk factors related to four modules that comprise the MYB intervention: physical activity, nutrition, mental health, and cognitive training. Targeting risk factors will enable interventions to be personalized so that participants receive the most appropriate modules. MYB will run for three years and up to four modules will be delivered sequentially each quarter during year one. Upon completing a module, participants will continue to receive less frequent booster activities for their eligible modules (except for the mental health module) until the end of the trial. Discussion: MYB will be the largest internet-based trial to attempt to prevent cognitive decline and potentially dementia. If successful, MYB will provide a model for not just effective intervention among older adults, but an intervention that is scalable for broad use.

Dementia is a leading cause of morbidity and mortality without pharmacologic prevention or cure. Mounting evidence suggests that adherence to a Mediterranean dietary pattern may slow cognitive decline, and is important to characterise in at-risk cohorts. Thus, we determined the reliability and validity of the Mediterranean Diet and Culinary Index (MediCul), a new tool, among community-dwelling individuals with mild cognitive impairment (MCI). A total of sixty-eight participants (66 % female) aged 75·9 (sd 6·6) years, from the Study of Mental and Resistance Training study MCI cohort, completed the fifty-item MediCul at two time points, followed by a 3-d food record (FR). MediCul test–retest reliability was assessed using intra-class correlation coefficients (ICC), Bland–Altman plots and κ agreement within seventeen dietary element categories. Validity was assessed against the FR using the Bland–Altman method and nutrient trends across MediCul score tertiles. The mean MediCul score was 54·6/100·0, with few participants reaching thresholds for key Mediterranean foods. MediCul had very good test–retest reliability (ICC=0·93, 95 % CI 0·884, 0·954, P<0·0001) with fair-to-almost-perfect agreement for classifying elements within the same category. Validity was moderate with no systematic bias between methods of measurement, according to the regression coefficient (y=−2·30+0·17x) (95 % CI −0·027, 0·358; P=0·091). MediCul over-estimated the mean FR score by 6 %, with limits of agreement being under- and over-estimated by 11 and 23 %, respectively. Nutrient trends were significantly associated with increased MediCul scoring, consistent with a Mediterranean pattern. MediCul provides reliable and moderately valid information about Mediterranean diet adherence among older individuals with MCI, with potential application in future studies assessing relationships between diet and cognitive function.

The Mediterranean diet is associated with multiple health benefits. Yet, no tool has been specifically developed to assess adherence to the ‘traditional’ Mediterranean diet and cuisine within a Western cohort, and validated for online use. We tested the reliability and validity of online administration of the Mediterranean Diet and Culinary Index (MediCul) among middle-aged and older adults. Participants were recruited in January–March 2017 from the 45 and Up Study, completing MediCul twice. Test-retest reliability was assessed using the paired t-test, intra-class correlation coefficient (ICC) and Bland-Altman plot. Validity was tested against a three-day food record (FR)-derived MediCul score using Bland-Altman and nutrient trends across the MediCul score tertiles. Participants (n = 84; 60% female; 65.4 years (SD = 5.9)), were overweight (BMI 26.1; SD = 4.0) with 1.7 (SD = 1.5) chronic illnesses/conditions. Sequential MediCul tool scores were 56.1/100.0 and 56.8/100.0, respectively (t = −1.019; p = 0.311). Reliability via ICC (ICC = 0.86, 95% CI: 0.789, 0.910, p < 0.0001) and Bland-Altman was good. In Bland-Altman validity analyses, the tool over-reported FR MediCul score by 5.6 points with no systematic bias ((y = 8.7 − 0.06*x) (95% CI: −0.278, 0.158, p = 0.584)). Nutrient trends were identified for MediCul consistent with expected Mediterranean patterns. Online MediCul administration demonstrated good reliability and moderate validity for assessing adherence to a ‘traditional’ Mediterranean pattern among older Australians.

Aim Nutrition‐based applications (“apps”) offer enormous research potential, however evidence of their use and acceptability among older adults is limited. We compared self‐reported and dietitian‐adjusted dietary intake records among adults aged 55 to 75 years using the Research Food Diary (RFD) app. Methods Participants were recruited from the 45 and Up Study and completed a 3‐day food record using the RFD. A follow‐up dietetic telephone interview was performed to confirm the electronic dietary data. Independent of these interviews, a set of adjustments based on dietetic skills, nutritional database knowledge, food composition and dietary assessment was established to resolve probable reporting errors. The “adjusted” and “dietitian‐assisted” records were compared to self‐reported records for nutrient intakes and serves of The Five Food Groups using one‐way repeated measures analysis of variance. Results Sixty‐two participants were recruited, with 48 using the RFD app which included eight records without any identified errors. Reporting errors contained in the raw self‐reported records included: food items with missing/implausible quantities or insufficient descriptions to allow automatic coding. After removal of unusable records, 44 records were analysed. Differences were found between the self‐reported and adjusted records for protein, calcium, vitamin B12, zinc and dairy food serves (all P < .001; differences up to 8%). No significant differences were found between the adjusted and dietitian‐assisted measures. Conclusions Similarities between adjusted and dietitian‐assisted records suggest carefully applied dietetic assumptions are likely to improve accuracy of self‐reported intake data where dietitian interviews are not possible. We provide four key recommendations to guide this process.

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The Maintain Your Brain trial (MYB) is one of the largest internet-delivered multidomain RCT designed to target modifiable risk factors for dementia. It comprises four intervention modules: physical activity, nutrition, mental health, and cognitive training. This paper explains the MYB Nutrition Module, which is a fully online intervention promoting the adoption of the ‘traditional’ Mediterranean Diet (MedDiet) pattern for those participants reporting dietary intake that does not indicate adherence to a Mediterranean-type cuisine or those who have chronic diseases/risk factors for dementia known to benefit from this type of diet. Participants who were eligible for the Nutrition Module were assigned to one of the three diet streams: Main, Malnutrition, and Alcohol group, according to their medical history and adherence to the MedDiet at baseline. A short dietary questionnaire was administered weekly during the first 10 weeks and then monthly during the 3-year follow-up to monitor whether participants adopted or maintained the MedDiet pattern during the intervention. As the Nutrition Module is a fully online intervention, resources that promoted self-efficacy, self-management, and process of change were important elements to be included in the module development. The Nutrition Module is unique in that it is able to individualize the dietary advice according to both the medical and dietary history of each participant; the results from this unique intervention will contribute substantively to the evidence that links the Mediterranean-type diet with cognitive function and the prevention of dementia and will increase our understanding of the benefits of a MedDiet in a Western country.

Background The Mediterranean‐style diet (MD) is promoted as one of the healthiest dietary patterns and has been shown to reduce cognitive decline in some randomised controlled trials (RCTs). This pattern is plant‐based with a focus on vegetables, legumes, fish, and olive oil, with low intake of red meats and foods high in sugar and saturated fats. The Maintain Your Brain (MYB) study is an online multi‐domain RCT targeting modifiable risk factors for dementia, including diet. This study investigated cross‐sectional associations between adherence to a MD pattern and cognition. Methods Participants enrolled in MYB were recruited from the Sax Institute’s larger 45 and Up Study, and included those with all baseline MYB assessments (n=6236). Diet was assessed using the validated Mediterranean Diet and Culinary Index tool. This 50‐item tool assesses intake of nine desirable and four undesirable features of the MD diet and allows derivation of the Mediterranean Diet Adherence Screener (MEDAS). Computerised cognitive tests, administered through the MYB digital platform, were used to assess domains of executive function, complex attention, learning and memory and global cognition. Results Participants were 46% male, with mean (SD) age 65.0 (5.8) years, BMI 26.6 (4.9) kg/m2 and well educated (46% with tertiary education). Higher MEDAS scores were associated with being female, younger, better educated and having a lower BMI (all p<0.001). Overall participant adherence to a MD pattern was low; MEDAS score 6.1 (2.1)/14. After covariate adjustment and correction for multiple analyses in hierarchical linear regression models, better MEDAS scores were significantly associated with worse (lower) z‐scores for executive function (β ‐0.018, p=0.003). For every 1‐point higher MEDAS score, executive function z‐scores were 0.018 lower. This unexpected negative association was clinically very small. There were no significant associations with other cognitive domains. Conclusion Adherence to a MD was sub‐optimal in this well‐educated Australian sample. The one unexpected finding is likely not clinically meaningful given its size. Additionally, as this was a cross‐sectional study, reverse causality cannot be ruled out. Results from the main MYB RCT will provide data on MD acceptance and impact in a Western dietary environment.