Nut Supplementation to Mitigate Post-stroke Cognitive Decline (NUT-me)

Stroke is a strong risk factor for dementia, with up to 80% of individuals having lower cognitive function 5 years after a stroke event. However, having a stroke does not need to result in declining cognition if effective strategies to reduce the risk of post stroke dementia are identified. Diets containing nuts can reduce the risk of both dementia and stroke but have not been tested in stroke survivors. Therefore, this pilot study aims to determine whether eating nuts regularly reduces post-stroke cognitive decline and dementia. The NUT-me pilot study will supplement the diet of stroke survivors with a mix of nuts containing walnuts, hazelnuts, almonds and Brazil nuts for 3 months and assess the effects on cognition and health markers. The researchers predict that regular nut consumption will contribute to preserving post-stroke cognitive function in comparison to patients who do not consume nuts. The results of this novel pilot study will be used to guide a larger trial and provide a simple dietary strategy that stroke survivors can adopt to reduce post-stroke cognitive decline.

This study will investigate the efficacy and feasibility of supplementing the habitual diet of stroke survivors with a supply of mixed nuts containing Brazil nut, walnuts, hazelnuts, and almonds to reduce post-stroke cognitive decline. The overall aim of this project will be achieved through the following objectives: Examine the feasibility through the assessment of compliance with the intervention and participants' perception of the study Investigate the efficacy of the intervention on cognitive decline, body composition and health outcomes (blood pressure, fasting glucose and insulin, and blood lipids) The investigators hypothesise that the inclusion of nuts is a simple dietary strategy that will slow post-stroke cognitive decline and that supplementation with nuts will improve body composition and health biomarkers of stroke survivors.

Participants will receive a supply of mixed nuts containing: 1 Brazil nut (~3g), walnuts (15g), hazelnuts (7g), and almonds (7g) to be consumed daily for 90 days. They will also receive dietary counselling on how to follow the Australian Dietary Guidelines.

Participants will follow the same protocol as the Nut group regarding appointments and collection of information. At the visits, they will receive dietary counselling on how to follow the Australian Dietary Guidelines

A mix of nuts containing 1 Brazil nut (~3g), walnuts (15g), hazelnuts (7g), and almonds (7g) to be consumed daily for 90 days. Dietary counselling on how to follow the Australian Dietary Guidelines

Cognitive performance after the 90-day intervention will be assessed in comparison to baseline by using the NIH Toolbox Cognition Battery V3. This validated battery encompasses 15 tests that are combined to generate composite scores by age: Crystalised Composite (which includes picture vocabulary and oral reading recognition tests) and Fluid Composite (which includes dimensional change card sort, flanker, picture sequence memory, list sorting, and pattern comparison tests).The Cognitive Function Composite Score is a combination of both crystallized and fluid scores. Higher scores indicate better cognitive performance.

Cognitive performance after the 90-day intervention will be assessed in comparison to baseline by using the NIH Toolbox Cognition Battery V3. This validated battery encompasses 15 tests that are combined to generate composite scores by age: Crystalised Composite (which includes picture vocabulary and oral reading recognition tests) and Fluid Composite (which includes dimensional change card sort, flanker, picture sequence memory, list sorting, and pattern comparison tests).The Cognitive Function Composite Score is a combination of both crystallized and fluid scores. Higher scores indicate better cognitive performance.

Cognitive performance after the 90-day intervention will be assessed in comparison to baseline by using the NIH Toolbox Cognition Battery V3. This validated battery encompasses 15 tests that are combined to generate composite scores by age: Crystalised Composite (which includes picture vocabulary and oral reading recognition tests) and Fluid Composite (which includes dimensional change card sort, flanker, picture sequence memory, list sorting, and pattern comparison tests).The Cognitive Function Composite Score is a combination of both crystallized and fluid scores. Higher scores indicate better cognitive performance.

Changes in the presence of depressive symptoms assessed by Patient Health Questionnaire (PHQ-9). The score ranges from zero to 27, with higher scores indicating worse depressive symptoms.

HOMA-IR is a measure of insulin resistance. It is calculated according to the formula: fasting insulin (microU/L) x fasting glucose (nmol/L)/22.5.

Inclusion Criteria: Ischaemic stroke (first or recurrent stroke) in the last 6 months Able to attend 4 study visits over 3 months Motivation and willingness to participate in the study protocol No prior neurological or psychiatric disease, including dementia Can give informed consent and participate in cognitive testing Exclusion Criteria: be < 18 years; have allergy to nuts have premorbid modified Rankin scale (mRS)≥4, denoting no severe disability incapable of giving consent have problems with mastication that preclude nut intake have habitual consumption of tree nuts (>2 servings/wk) in the previous 2 months have habitual consumption of alpha-linolenic acid supplements (fish oil, flaxseed oil, and/or soy lecithin) have dementia or psychiatric disease do not speak English

This is a small pilot study and the generated data will be used only by the Principal Investigator as preliminary data in grant applications and potentially one publication (yet to be decided).