The Effect of Pistachio-Rich Breakfast Meals on Cognitive Function in Healthy Older Adults

Official title

A Randomized Controlled Trial to Investigate the Cognitive, Vascular, Neural and Biochemical Effects of Acute Pistachio Intervention in Older Adults

Overview

This study aims to investigate the effect of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on cognitive function throughout the course of the day in healthy ageing adults aged 65-80.

Detailed description

This crossover RCT investigates the acute postprandial effect (over a 6-hour period) of a breakfast meal containing varying serving sizes (doses) of pistachio nuts on the cognitive behaviour in healthy adults aged 65-80 years old. The study will also assess markers of inflammation and brain health by taking blood samples, and explore brain function (EEG) and blood flow (FMD) to understand how pistachio nuts may positively influence cognitive health. The study will involve a screening visit and four testing visits, with a week interval between each. On the evening prior to each test visit, participants are asked not to consume any food or drinks expect water, including tea/coffee and alcohol, after 8.30pm, and on the morning of test visits to only consume one slice of buttered white toast and a glass of water prior to attending the visit. During the four testing visits, cognitive and mood battery tests will be taken at baseline and then at 2-, 4- and 6-hour intervals following the consumption of the intervention meal. Blood draws are taken at the end of the day. For the subset of participants taking part in FMD, this will be measured at baseline, 2, 4 and 6 hours prior to cognitive testing. For those taking part in EEG, this data will be collected at 6 hours.

Interventions

• Dietary supplement 0.5 serving of pistachios
  The equivalent of 0.5 servings (15g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 15g pistachio, 35g muesli base, 150g full fat natural yoghurt, 15g unsalted butter (melted), 10g unflavoured whey powder
• Dietary supplement 1 serving of pistachios
  The equivalent of 1 serving (30g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 30g pistachio, 35g muesli base, 150g full fat natural yoghurt, 10g unsalted butter (melted), 5g unflavoured whey powder
• Dietary supplement 2 servings of pistachios
  The equivalent of 2 servings (60g) of shelled, roasted pistachio nuts, crushed and mixed into a muesli-based breakfast meal for consumption. Ingredients: 60g pistachios, 25g muesli base, 150g low fat natural yoghurt
• Dietary supplement Placebo
  Macronutrient-matched placebo breakfast meal. Ingredients: 40g muesli base, 150g full fat natural yoghurt, 25g unsalted butter (melted), 15g unflavoured whey powder

Primary outcome measures

• Delayed recall (Rey Auditory Verbal Learning Task) [Time frame: Baseline]
• Delayed recall (Rey Auditory Verbal Learning Task) [Time frame: 2 hours]
• Delayed recall (Rey Auditory Verbal Learning Task) [Time frame: 4 hours]
• Delayed recall (Rey Auditory Verbal Learning Task) [Time frame: 6 hours]

Secondary outcome measures (12)

• Rate of learning (Rey Auditory Verbal Learning Task) [Time frame: Baseline]
• Rate of learning (Rey Auditory Verbal Learning Task) [Time frame: 2 hours]
• Rate of learning (Rey Auditory Verbal Learning Task) [Time frame: 4 hours]
• Rate of learning (Rey Auditory Verbal Learning Task) [Time frame: 6 hours]
• Word recognition (Rey Auditory Verbal Learning Task) [Time frame: Baseline]
• Word recognition (Rey Auditory Verbal Learning Task) [Time frame: 2 hours]
• Word recognition (Rey Auditory Verbal Learning Task) [Time frame: 4 hours]
• Word recognition (Rey Auditory Verbal Learning Task) [Time frame: 6 hours]
• Modified Attention Network Task (MANT) [Time frame: Baseline]
• Modified Attention Network Task (MANT) [Time frame: 2 hours]
• Modified Attention Network Task (MANT) [Time frame: 4 hours]
• Modified Attention Network Task (MANT) [Time frame: 6 hours]

Eligibility criteria

Inclusion criteria

• 65 - 80 years old
• Fruit \& veg intake less than or equal to 4 servings per day
• Not regularly consuming more than 3 servings of fish per week
• Adequate English language and visual \& auditory acuity to perform the cognitive tasks
• Normal BMI for age
• Normal MMSE performance between 26-30

Exclusion criteria

• Being diagnosed with psychological or psychiatric disorders
• ADHD or dyslexia
• Any food allergy or intolerance
• Use of medications and dietary supplements that may impact study results
• Antibiotic use within the last 3 months
• Adherence to vegan or vegetarian diets, or other specific diets that may impact study outcomes
• Being diagnosed with cardiometabolic disease (including type II diabetes and cardiovascular disease), or suffer from untreated hypertension or thrombosis related disorders
• Taking blood thinners

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Crossover

Masking

Triple blind

Primary purpose

Treatment

Study locations

United Kingdom · 1 center

• Nutrition, Cognition & Health Lab, School of Psychology and Clinical Language Sciences, Un — Reading

Identifiers

NCT: NCT06900452 · 2024-236-CW

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗