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

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

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.

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.

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