None listed
Conditions
Brief summary
Previous research has shown that older adults (i.e., 60 years and above) may require higher protein intake to preserve muscle mass, strength, and function. However, increasing protein intake can be difficult for multiple reasons such as reduced appetite, reduced protein digestion and absorption compared to younger adults, price/ cost, logistics, and that protein, naturally, is highly satiating (i.e.: it makes you feel full). In addition to consuming whole-food protein sources, protein-enriched supplements such as protein powders are convenient and high-quality protein sources that have been shown to help increase and maintain muscle mass. Of the many different protein supplements available on the commercial market, whey protein, which is derived from milk during the cheese-making process, is one of the most popular forms. Whey protein can be purchased in three primary forms: (1) Whey protein concentrate which is the least processed form of whey protein (70-80% protein by weight) that subsequently retains more of the naturally occurring fats, carbohydrates, and lactose found in whey; (2) Whey protein isolate, as its name suggests, isolates more protein (typically around 90% or more protein by weight) such that most of the fat, lactose, and other non-protein components are removed; (3) Whey protein hydrolysate, which is also typically around 90% or more protein by weight, undergoes a specialised processing technique called enzymatic hydrolysis which breaks down protein molecules into segments. As such, this form of whey protein is often considered the most easily digestible and rapidly absorbed. The purpose of this study is to gain insight into whether a whey protein hydrolysate and concentrate blend can be digested as effectively as a straight whey protein hydrolysate while still containing many of the beneficial naturally occuring fats and carbohydrates which can be important for immune and body health.
Interventions
The study will incorporate a randomised, blinded, cross-over study consisting of three experimental trial mornings at Swinburne University. Each of the experimental trial mornings (described below) will be separated (i.e., ‘wash-out’ period) by a minimum 4 days. On the experimental days, participants will be randomly allocated to consume one of three whey protein beverages:
1) 250ml of 0.4 g/kg whey hydrolysate and concentrate blend (50% volume of each 100% hydrolysate and 100% concentrate as in
The study will incorporate a randomised, blinded, cross-over study consisting of three experimental trial mornings at Swinburne University. Each of the experimental trial mornings (described below) will be separated (i.e., ‘wash-out’ period) by a minimum 4 days. On the experimental days, participants will be randomly allocated to consume one of three whey protein beverages: 1) 250ml of 0.4 g/kg whey hydrolysate and concentrate blend (50% volume of each 100% hydrolysate and 100% concentrate as indicated below) mixed in water. 2) 250ml of 0.4 g/kg 100% whey protein hydrolysate mixed in water (100% whey protein hydrolysate containing approximately 90% protein). 3) 250ml of 0.4 g/kg 100% whey protein concentrate mixed in water (100% whey protein concentrate containing approximately 74% protein). The selected dose of each whey protein beverage is based on previous research demonstrating this quantity of protein to maximally stimulate muscle protein synthesis in older adults which is an amount that can practically translated into habitual lifestyles. All protein beverages will be mixed in water in the Dietetics facility at Swinburne University using commercially available protein supplement shakes. Whey protein beverages will be provided in a restricted random order based on the recruitment order to ensure that an equal number of participants receive the three intervention beverages on experimental days one, two and three, respectively. One of the primary investigators who will not take an active part in the blood sampling procedures or the following laboratory analysis (described subsequently) will perform the randomisation. Participants will be blinded to the content and order of the intervention beverages. Participants will first undertake a preliminary visit (‘Visit 1’) to provide the research team a signed medical clearance form from their local GP, complete/sign the study consent form, undertake measurements for BMI (height and weight) as well as body composition measure on a bioelectrical impedance scale). Within the next 1-2 weeks in the lead up to an experimental trial morning (described subsequently), participants will be instructed to refrain from exercise training and vigorous physical activity and alcohol consumption for a minimum of 48 hours. Participants will also be provided with standardised prepacked meals consisting of 3 g carbohydrate g/kg body mass, 0.5 g protein g/kg body mass, and 0.3 g fat g/kg body mass in the form of Spaghetti Bolognese, jelly, muesli bar and fruit to be consumed as the final caloric intake the evening before reporting for an experimental trial. Participants will be instructed to record their dietary intake and physical activity level on the day before the first trial. These recordings will be used as a standard plan before the following trial days to ensure standardisation of dietary intake and physical activity level. To monitor adherence to the standardised diet, participants will be provided a sheet with tick boxes next to each food item to tick if they have fully consumed that food item and a notes section to write any notes if a good item has not been fully consumed. On the morning of an experimental trial, participants will arrive to the Clinical Space in Building SPW at Swinburne University after an approximately 10-h overnight fast (nil food with ad libitum water allowed). After resting for approximately 15 min, a catheter will be inserted by a qualified phlebotomist into the antecubital vein of a preferred arm and a baseline blood sample (approximately 5 mL) will be obtained. Participants will then consume one of the three whey protein drinks outlined above. Participants will be instructed to consume the drink within 2 min (under the direct supervision of the research team) at which the time will be designated as time zero. Additional blood samples (approximately 5ml each) will be obtained at 15 min, 30 min, 45 min, 60 min, 120 min, 180 min and 240 min following beverage consumption for a total of 8 samples and 40 mL of blood. During this time, participants will remain in a resting position will be required to abstain from any food or beverages throughout the trial hours. Participants will also complete a simple Likert Scale to evaluate taste of each beverage throughout the recovery period. At the completion of the four-hour trial, participants will be provided a meal prior to departing the Swinburne campus.
Sponsors
Swinburne University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator)
Eligibility
Sex/Gender
All
Age
60 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
• Aged between 60-80 years. • Community-dwelling (i.e.: not living in an aged-care facility, etc) • Have a Body Mass Index (BMI) between 18.5-35 • Deemed healthy based on responses to a medical questionnaire designed specifically for this study
Exclusion criteria
(1) Being aged <60 years or >80 years of age (2) Known dairy allergies or intolerances to lactose (3) Any known gastrointestinal (GI) disorders or renal/kidney (acute or chronic) disease) (4) The use of medication that could influence absorption after food intake (5) High blood pressure/ hypertension (>140/90 mmHg) (6) Use of supplements during the trial period (7) Weight loss or gain of more than 2 kg during the preceding 6-weeks to the trial period (8) Inability to stand unaided, or (9) inability to commit to the study and its requirement.
Outcome results
None listed