The purpose of this study is to investigate the short-term effects of milk and yogurt of varying fat and protein content on cognitive performance in healthy children aged 9 - 14 years; and to provide insight into mechanisms by which dairy consumption may affect cognitive performance through gastrointestinal (GI) hormone responses. The investigators hypothesize that the consumption of dairy products, specifically their protein and fat components, will improve cognitive performance via its interaction with the gut-brain axis in children. Furthermore, the investigators hypothesize that all milk and yogurt products will enhance cognitive performance over 120- mins compared to snack skipping through its interaction with GI hormones, with a greater effect in higher fat containing milk and yogurt products.
A randomized within-subject repeated measures experiment will be used to study the effect of milk and yogurt of varying fat content on cognitive performance and its interaction with GI hormones in children (9-14 years). Participants will consume milk \[Experiment A\] and yogurt \[Experiment B\] test treatments, followed by measures of cognitive performance, blood glucose and GI hormone biomarkers over 120-min. In Experiment A and B, participants will consume, in a random order on separate mornings, one of four test treatments: (1) Full-fat, (2) Low-Fat, (3) No-fat, and (4) Snack-skipping test treatments. Cognitive domains (learning and memory, spatial working memory, attention, processing speed, and executive function), gastrointestinal hormone response, and subjective emotions will be assessed at baseline (0-min), and 30-, 60-, and 120-min following treatment consumption.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
48
Fat-free milk (500 mL, skim, 0%, Lactantia PurFiltre) will provide 180 kcal, 0.4 g fat, 26 g carbohydrate, and 18 g protein. Treatments matched for calories (180 kcal).
Low-free milk (346 mL, 2%, Lactantia PurFiltre) will provide 180 kcal, 6.9 g fat, 16.6 g carbohydrate, and 12.5 g protein. Treatments matched for calories (180 kcal).
Full-free milk (281 mL, 3.25%, Lactantia PurFiltre) will provide 180 kcal, 9.0 g fat, 13.5 g carbohydrate, and 10.1 g protein. Treatments matched for calories (180 kcal).
Snack skipping (no caloric contribution).
Fat-free Yogurt (242.3 g, Oikos High Protein Vanilla; 0% MF) will provide 180 kcal, 0 g fat, 20.8 g carbohydrate, and 23.5 g protein. Treatments matched for calories (180 kcal).
Low-fat Yogurt (210.0 g, Oikos Original 2% MF) will provide 180 kcal, 3.6 g fat, 21.6 g carbohydrate, and 15.6 g protein. Treatments matched for calories (180 kcal).
Full-fat Yogurt (185.3 g, Oikos Extra Creamy Vanilla 9% MF) will provide 180 kcal, 15.9 g fat, 21.2 g carbohydrate, and 6.4 g protein. Treatments matched for calories (180 kcal).
Toronto Metropolitan University
Toronto, Ontario, Canada
RECRUITINGLearning and short-term memory
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Learning and short-term memory will be assessed using an immediate and delayed Word Recall Test (accuracy).
Time frame: Immediate measured at 30-minutes post-treatment and delayed at 60- and 120-minutes post-treatment consumption
Spatial working memory
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Spatial working memory will be assessed using the forward and backward versions of the Corsi Block Test (accuracy).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Sustained Attention
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Sustained attention and processing speed will be assessed using the Continuous Performance Test (CPT) (accuracy).
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Executive Function
Cognitive performance tests will be administered via a Dell tablet (Millisecond, Inquisit Web) and paper/pen. Executive function and selective attention will be assessed using the Flanker Task (accuracy)
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Subjective mood and emotion
A visual analogue scale (VAS) with twelve questions will be administered to assess subjective emotions and mood (aggression, anger, excitement, disappointment, happiness, upset, frustration, alertness, sadness, tension, calmness, sleepiness, and wellness). Individual questions will be used to form a composite emotion score. Each VAS will be administered via a digital software application (Express VAS, Toronto, Ontario, Canada) on a Dell tablet where children will place an 'X" on the VAS line (100 unit scale) to describe their feelings.
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 30-minutes, 60-minutes and 120-minutes post-treatment consumption
Gastrointestinal Hormone Response
Blood biomarkers will include glucose, insulin, active GLP- 1, and total GIP. Blood samples will be collected via a venous catheter inserted into the participants arm by a Registered Nurse
Time frame: Change from baseline (measured at 0-minutes before treatment) and at 30-minutes, 60-minutes and 120-minutes post-treatment consumption
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.