Habitual Protein Intake and Muscle Protein Synthesis
Information source: Maastricht University Medical Center
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Sarcopenia
Intervention: Protein diet (Dietary Supplement)
Phase: N/A
Status: Completed
Sponsored by: Maastricht University Medical Center Official(s) and/or principal investigator(s): Luc JC van Loon, PhD, Principal Investigator, Affiliation: Maastricht University Medical Center
Summary
Protein intake stimulates muscle protein synthesis. From the standpoint of maintaining
skeletal muscle mass with aging, it is important to optimize the adaptive response to food
intake. However, a paucity of information is available describing the effects of habitual
dietary protein intake (i. e. either high or low amounts of dietary protein consumed on a
regular basis), on the subsequent meal-induced stimulation of muscle protein synthesis. An
adaptation to a diet of several days or weeks may involve splanchnic and/or skeletal muscle
adaptations that may further enhance, or decrease, the amino acid sensitivity of muscle
protein synthesis after protein ingestion.
The aim of this study is to investigate the effect of a habitual (14 days) high protein diet
when compared with low protein diet on digestion and absorption kinetics and the subsequent
muscle protein synthetic response to dietary protein ingestion.
Clinical Details
Official title: The Impact of Habitual Dietary Protein Intake on the Anabolic Response in Elderly Men
Study design: Allocation: Randomized, Endpoint Classification: Bio-availability Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Prevention
Primary outcome: Muscle protein synthesis rates
Secondary outcome: Digestion/Absorption kinetics
Detailed description:
During the adult life skeletal muscle mass remains fairly constant until the fourth or fifth
decade. Then, the slow process of sarcopenia (the age-related loss of muscle mass) is
believed to begin. The maintenance of skeletal muscle mass is regulated by a balance between
the opposing processes of muscle protein synthesis and muscle protein breakdown. Food
intake, dietary protein in particular, stimulates muscle protein synthesis and allows net
muscle protein accretion throughout the day, which allows the normal maintenance of muscle
mass in healthy individuals. Many studies have described the postprandial muscle protein
synthetic response to protein intake and/or physical activity, and these acute findings have
led to recommendations for protein intake for both athletes wishing to gain muscle mass as
well as patients and elderly individuals to help them maintaining muscle mass. However,
translating the acute findings from a single meal to long-term recommendations is perhaps
premature, since scientists know very little with regard to how previous consumed meals
affect the anabolic responsiveness to subsequent food intake. A characteristic of the
adaptation to habitual high or low protein intake is thought to be associated with a change
in the amplitude of diurnal cycle of whole body proteins. If this speculation is accurate,
it implies that the muscle protein synthetic responses to feeding (differences between
fasting and feeding muscle protein synthesis rates) are adapting to differing habitual
protein intake, which may reduce (or enhance) the anabolic responsiveness to protein intake.
To gain a more complete scientific understanding, it is necessary to examine whether an
adaptation does in fact occur after habitual high or low amounts of protein intake with
regard to the anabolic response to subsequent protein intake. In the present investigation,
we wish to investigate the impact of the habitual consumption of either high or low protein
diets for 14 days on the anabolic responsiveness to a protein meal in healthy elderly.
Previous work has determined that whole body adaptations to protein intake occur after >10
days. Collectively, our findings will be valuable to maximize the skeletal muscle adaptive
response to food intake and, ultimately, to develop nutritional strategies for maintenance
or enhancement of skeletal muscle mass in elderly men.
Eligibility
Minimum age: 55 Years.
Maximum age: 75 Years.
Gender(s): Male.
Criteria:
Inclusion Criteria:
- Healthy males
- Age between 55 and 75 y
- BMI between 18. 5 and 30 kg/m2
Exclusion Criteria:
- Lactose intolerance
- Smoking and alcohol abuse
- Diabetes
- Diagnosed GI tract diseases
- Arthritic conditions
- A history of neuromuscular problems
- Any medications known to affect protein metabolism (i. e. corticosteroids,
non-steroidal anti-inflammatories, or prescription strength acne medications).
- Use of anticoagulants
- Participation in exercise program
- Hypertension, high blood pressure that is above 140/90 mmHg.
Locations and Contacts
Maastricht University, Maastricht, Limburg 6200 MD, Netherlands
Additional Information
Starting date: January 2014
Last updated: November 27, 2014
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