Metabolite Changes Following Consumption Of Different Protein Drinks In Singapore Older Adults

This study will be a double-blind, randomised, placebo-controlled trial using a crossover study design. 25 older adults (aged 60 to 80) will be recruited and assigned to consume 4 different test drinks in a random order on 4 different visits. This study aims to investigate whether higher protein consumption of different sources will influence postprandial plasma and urinary metabolomic profiles, cognition, mood and appetite. The study will comprise 1 screening visit and 4 test visits separated separated by a minimum washout period of >7 days

Inclusion criteria

• English-literate and able to give informed consent
• Adults 60 to 80 years old (inclusive)
• (If applicable) Postmenopausal
• BMI of 18·5 to 30 kg/m2 (inclusive)

Exclusion criteria

• Currently participating in another clinical study that involves altering the regular diet and/or involves consuming a dietary supplement or investigated food product as an intervention
• Weight change >3 kg in the past 3 months
• Exercising vigorously over the past 3 months (i.e., engaging in high-intensity exercises for more than 3 hours a week, where high-intensity exercises leave one out of breath and unable to talk or sing during the workout)
• Current smokers or have quit smoking for less than 5 years
• Drinking >2 alcoholic drinks per day (i.e., one drink is defined as either 150 ml of wine, 340 ml of beer/cider or 45 ml of distilled spirit)
• If drinking ≤2 alcoholic drinks per day, not willing to stop consumption of alcoholic beverages two days before and on the day of the test visits (total 12 days)
• Not willing to stop consumption of caffeinated beverages 10 to 12 hours before and on the day of the test visits (total 4 days)
• Taking supplements containing omega-3, magnesium, gamma-aminobutyric acid (GABA), L-theanine, melatonin and/or 5-hydroxytryptophan for the past 3 months, and not willing to discontinue usage 3 months before and during the study duration
• Currently on a specialised diet (e.g., vegetarian, vegan, weight loss diet)

• Had serious food allergies in the past, or having intolerance, sensitivities or allergies to any of the following: milk/dairy products (e.g., casein, whey), starch/starch-derived products (e.g., rice, corn, wheat, potato), soy/soy-derived products, gluten, eggs, nuts, peanuts, fish and crustaceans.
• Disease or impairment of the kidney and/or liver
• Currently diagnosed with diabetes, sleep disorders, gastrointestinal issues (e.g., lactose intolerance, irritable bowel syndrome), gout and/or G6PD deficiency
• History of diseases known to affect the central nervous system (e.g., heart disease, stroke, migraine headaches, multiple sclerosis, Parkinson's disease, mental illnesses)
• Taking antibiotics 2 weeks prior to study participation
• Taking medication known to interfere with cognitive function and mental wellbeing (e.g., benzodiazepines, antidepressants, other central nervous agents)
• Taking anti-hypertensive or cholesterol-lowering drugs for less than 3 years unless medically declared by an official doctor to be in stable condition
• Poor peripheral venous access based on past experiences with blood drawing