MIND Diet and Cognitive Function in Adults With MCI

To examine the effects of a 1-year cluster-randomized controlled intervention of MIND diet on cognitive function among 240 participants with mild cognitive function (MCI) aged 50 years and above from 4 communities.

The current study is a 1-year cluster-randomized controlled intervention trial designed to examine whether the a localized modified Mediterranean-Dietary Approaches to Stop Hypertension (DASH) dietary intervention for neurodegenerative delay (MIND) diet will improve cognitive function among 240 participants with MCI from 4 communities. The modified MIND diet recommends 11 brain healthy food groups (green leafy vegetables, dark red and yellow vegetables, other vegetables, nuts, berries, beans, whole grains, seafood, poultry, olive/tea-seed oil and green tea) and limits intake of 4 unhealthy food groups (red meat and products, animal oil, pastries and sweets, and fried/fast food). This study will randomly assign 240 MCI participants to two groups: A) MIND diet intervention group and B) control group, and estimate the cognitive and biological impacts of the 1-year intervention.

Participants in the MIND diet group will receive an education program on a localized MIND diet for 1-year, and will be routinely followed up and given advice on other healthy lifestyles.

Participants in the control group will be routinely followed up and given general advice on healthy lifestyle.

An intensified education program following a localized modified MIND diet for 1 year, which recommends 11 brain healthy food groups (green leafy vegetables, dark red and yellow vegetables, other vegetables, nuts, berries, beans, whole grains, seafood, poultry, olive/tea-seed oil and green tea) and limits intake of 4 unhealthy food groups (red meat and products, animal oil, pastries and sweets, and fried/fast food).

Global cognitive performance (composite z-score) measured by comprehensive Neuropsychological Test Battery (NTB). The z-score calculation will use the population mean and standard deviation, and a higher z-score indicates better cognitive performance.

NTB domain-specific cognitive performance (composite z-score) for memory, executive function, attention, language, visuomotor speed and visuoconstruction. The z-score calculation will use the population mean and standard deviation, and a higher z-score indicates better cognitive performance.

The Clinical Dementia Rating-Sum of Boxes (CDR-SB) is scored from 0 to 18. Higher scores reflect worse performance.

Change in Alzheimer's Disease Cooperative Study Activities of Daily Living Mild Cognitive Impairment-Activities of Daily Living Inventory (ADCS MCI-ADL)

The Alzheimer's Disease Cooperative Study Activities of Daily Living-Mild Cognitive Impairment-Activities of Daily Living Inventory (ADCS MCI-ADL) is scored from 0 to 53. Higher scores reflect better performance.

The Pittsburgh Sleep Quality Index (PSQI) is scored from 0 to 21. Higher scores indicate worse sleep quality.

To evaluate the behavioural effect of dietary changes of the MIND diet intervention package. Exploratory aim 1b: Changes in plasma levels of carotenoids, fatty acids, and vitamins (including folic acid). To evaluate the effect on nutritional biomarkers of the MIND diet intervention.

To evaluate the effect on the depressive status of the MIND diet intervention. A higher GDS score indicates more severe depressive symptoms.

To evaluate the effect on the anxiety status of the MIND diet intervention. A higher GAD-7 score indicates more severe anxious symptoms.

To evaluate the effect on plasma metabolites of the MIND diet intervention. We will assay the metabolome using liquid chromatography-mass spectrometry (LC-MS) and construct an overall metabolic score of the diet as the outcome.

To evaluate the effect on systematic inflammation of the MIND diet intervention. We will assay interferon-γ, Interleukin (IL)-10, IL-12p70, IL-13, IL-1β, IL-2, IL-4, IL-6, IL-8, Tumor Necrosis Factor alpha, and C-Reaction Protein and construct an overall plasma inflammatory biomarker score as the outcome.

To evaluate the effect on intestinal microbiome biodiversity and abundance in specific species in faecal samples of the MIND diet intervention. We will assay microbiome using 16-S ribosomal RNA (rRNA) sequencing and construct an overall intestinal microbiome score as the outcome.

Inclusion Criteria: At risk of cognitive decline: cognitive performance at the mean level or slightly lower than expected for age with no dementia (AD8>=3 and/or 5-min MoCA < 11) Free of physical disabilities that preclude participation in the study Willing to complete all study-related activities for 24 months Willing to be randomized to either intervention group Exclusion Criteria: Allergic to more than one type of food (nuts, berries, olive oil, or fish) Diagnosed of dementia, severe diabetes mellitus, cardiovascular disease, cancer, thyroid disease, kidney disease, or liver disease Diagnosed of major depression or other neuropsychological diseases Severe loss of vision, hearing or communicative ability Substance abuse within 6 months or heavy alcohol consumption (> 2 drinks/day for women; > 3 drinks/day for men).

When the final research data published, the data and other related resources would be shared in the Global Alzheimer's Association Interactive Network (GAAIN).

Chen H, Dhana K, Huang Y, Huang L, Tao Y, Liu X, Melo van Lent D, Zheng Y, Ascherio A, Willett W, Yuan C. Association of the Mediterranean Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) Diet With the Risk of Dementia. JAMA Psychiatry. 2023 Jun 1;80(6):630-638. doi: 10.1001/jamapsychiatry.2023.0800.

Huang L, Tao Y, Chen H, Chen X, Shen J, Zhao C, Xu X, He M, Zhu D, Zhang R, Yang M, Zheng Y, Yuan C. Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) Diet and Cognitive Function and its Decline: A Prospective Study and Meta-analysis of Cohort Studies. Am J Clin Nutr. 2023 Jul;118(1):174-182. doi: 10.1016/j.ajcnut.2023.04.025. Epub 2023 Apr 25.

Morris MC, Tangney CC, Wang Y, Sacks FM, Barnes LL, Bennett DA, Aggarwal NT. MIND diet slows cognitive decline with aging. Alzheimers Dement. 2015 Sep;11(9):1015-22. doi: 10.1016/j.jalz.2015.04.011. Epub 2015 Jun 15.

Liu X, Morris MC, Dhana K, Ventrelle J, Johnson K, Bishop L, Hollings CS, Boulin A, Laranjo N, Stubbs BJ, Reilly X, Carey VJ, Wang Y, Furtado JD, Marcovina SM, Tangney C, Aggarwal NT, Arfanakis K, Sacks FM, Barnes LL. Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) study: Rationale, design and baseline characteristics of a randomized control trial of the MIND diet on cognitive decline. Contemp Clin Trials. 2021 Mar;102:106270. doi: 10.1016/j.cct.2021.106270. Epub 2021 Jan 9.