The Importance of Dietary Protein Quality for Muscle Anabolism.
Research type
Research Study
Full title
The Importance of Dietary Protein Quality for Skeletal Muscle Anabolism in Older Adults
IRAS ID
291370
Contact name
Leigh Breen
Contact email
Sponsor organisation
University of Birmingham
Duration of Study in the UK
3 years, 0 months, 1 days
Research summary
Normal ageing is associated with declines in muscle mass and strength. Such losses can precipitate risk of falls, lowered activity level and compromised quality of life. Many older adults have a poorer appetite and less income compared to younger individuals. Consequentially, ability to eat large protein doses are unfeasible for much of this older population. Furthermore, with advancing age participation in physical activity, particularly resistance-type exercise is rare. However both protein, specifically essential amino acid (EAA) availability, and resistance-type exercise are pertinent anabolic signals for increasing muscle protein synthesis (MPS). With lifestyles which do not maximise MPS, this older demographic is at particular risk of accelerated muscle loss and earlier dependence, especially since such anabolic signals need to be greater in this population given an 'anabolic resistance' with ageing. Increasing protein quality may be a feasible method to increase anabolic signalling to promote muscle hypertrophy and strength, particularly when combined with resistance exercise training. Increasing protein quality has potential to minimise profound declines in MPS, by increasing EAA consumption throughout the day by enriching existing meals posing high efficacy, without significant cost or negative appetite responses.
Forty healthy 50-70 year olds will be recruited. Twenty will be randomly allocated to high-quality protein trial (3:1 animal:plant) supplemented with whey and the remaining 20 to low-quality protein (1:3 animal:plant) supplemented with pea protein. Dietary intake and habitual activity will be monitored throughout. Body composition (DXA), muscle architecture (ultrasound), muscle strength and activation (MVC with interpolated twitch) and muscle protein synthesis (MPS) will be assessed at the before and end of 10-day intervention which features adherence to high- or low-quality protein diet alongside bi-daily unilateral resistance exercise training. To evaluate MPS, participants will consume D2O bolus daily where presence will be assessed in saliva samples and muscle biopsies from trained and untrained legs.
REC name
London - Surrey Borders Research Ethics Committee
REC reference
21/LO/0401
Date of REC Opinion
23 Jun 2021
REC opinion
Further Information Favourable Opinion