(KIWI) Speeding up a Slow Protein for Muscle Mass With Hay Kiwifruit

Study Overview
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Brief Summary
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The specific hypothesis is that the consumption of 2 Hayward green kiwifruit (containing actinidin protease) prior to 100g of ground beef will increase the rate of protein digestion from the beef in the elderly, leading to an increased uptake of the essential amino acids. Furthermore, this increased essential amino acid availability will produce a greater postprandial net anabolic protein response, as well as increased fractional synthetic rates of muscle proteins.

Detailed Description
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The specific hypothesis is that the consumption of 2 Hayward green kiwifruit (containing actinidin protease) prior to 100g of ground beef will increase the rate of protein digestion from the beef in the elderly, leading to an increased uptake of the essential amino acids. Furthermore, this increased essential amino acid availability will produce a greater postprandial net anabolic protein response, as well as increased fractional synthetic rates of muscle proteins. To test this hypothesis, the investigators will use a double-blinded crossover design involving two intervention arms; in both arms 100g of ground beef (cooked weight) will be consumed following either 2 Hayward green kiwifruit (containing actinidin protease) or 2 Hort16A Gold kiwifruit (devoid of actinidin protease) by elderly subjects.

Official Title
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(KIWI) Speeding up a Slow Protein for Muscle Mass With Hay Kiwifruit

Conditions
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Metabolism, Protein

Intervention / Treatment
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* Dietary Supplement: Green Hayward Kiwifruit first, then Gold Kiwifruit
* Dietary Supplement: Gold Kiwifruit First, then Green Hayward Kiwifruit


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: men and women ages 60-85 inclusive. Exclusion Criteria: Inability to chew meats or difficulty swallowing solid foods History of diabetes History of malignancy in the 6 months prior to enrolment History of gastrointestinal reduction or bypass surgery (Lapband, etc) History of a chronic inflammatory condition or disease (Lupus, HIV'AIDS, etc) History of chronic kidney disease or currently requiring dialysis. Allergy to beef or kiwifruit Subjects who do not or will not eat animal proteins Subjects who cannot refrain from consuming protein or amino acid supplements during their participation in this study Subjects who report regular resistance exercise (more than once per week) Hemoglobin less than 9.5mg/dL at the screening visit Platelets less than <150,000 at the screening visit Subjects who are not willing or able to suspend aspirin for several days prior to their muscle biopsies. Subjects who have been prescribed a blood-thinning medication (Coumadin, lovenox, heparin, Plavix, etc). Concomitant use of corticosteroids (ingestion, injection or transdermal) Any other disease or condition that would place the subject at increased risk of harm if they were to participate, at the discretion of the study physician

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Subjects crossed over between ingesting 2 different types of kiwifruit for 2 weeks prior to each stable isotope metabolic study.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Gold Kiwifruit First, then Green Hayward Kiwifruit<br>Subjects first ate 2 gold kiwifruit with midday meal for 2 weeks before crossing over to the green Hayward kiwifruit intervention | Dietary Supplement: Green Hayward Kiwifruit first, then Gold Kiwifruit<br>* Subjects ate 2 peeled green kiwifruit with their midday meal for 2 weeks prior to testing.<br>Dietary Supplement: Gold Kiwifruit First, then Green Hayward Kiwifruit<br>* Subjects ate 2 peeled gold kiwifruit with their midday meal for 2 weeks prior to testing.<br>|
| Active Comparator: Green Hayward Kiwifruit first, then Gold Kiwifruit<br>Subjects first ate 2 green Hayward kiwifruit with midday meal for 2 weeks before crossing over to the gold kiwifruit intervention | Dietary Supplement: Green Hayward Kiwifruit first, then Gold Kiwifruit<br>* Subjects ate 2 peeled green kiwifruit with their midday meal for 2 weeks prior to testing.<br>Dietary Supplement: Gold Kiwifruit First, then Green Hayward Kiwifruit<br>* Subjects ate 2 peeled gold kiwifruit with their midday meal for 2 weeks prior to testing.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Whole Body Net Balance Measured by Gas Chromatography-Mass Spectrometry (GC-MS) | Blood samples were analyzed to quantify the appearance of the stable isotopes: 2H2-tyrosine, 2H4-tyrosine, and 2H5-phenylalanine in tracer to tracee ratio or mole percent excess. Changes in these markers over time enable the calculation of whole body protein metabolism. Calculations are done as follows: Total plasma rate of appearance = infusion rate/enrichment Fractional rate of appearance of tyrosine from phenylalanine= 2H4-tyrosine/2H5-phenylalanine Phenylalanine hydroxylation = fractional rate of appearance of tyrosine from phenylalanine x rate of appearance of tyrosine Protein Synthesis = [(rate of appearance of phenylalanine -Phe hydroxylation) x 25] Protein Breakdown = [(rate of appearance of phenylalanine - phenylalanine infusion rate) x 25 - phenylalanine intake] Net Balance = Protein Synthesis - Protein Breakdown | 300 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Skeletal Muscle Protein Metabolism Measured by Gas Chromatography-Mass Spectrometry (GC-MS) | Muscle samples were analyzed to quantify the appearance of the stable isotope 2H5-phenylalanine in trace to tracee ratio or mole percent excess. The change in 2H5-phenylalanine in subsequent muscle biopsy allow for the calculation of muscle protein synthesis. The calculation is done as follows: [(2H5-phenylalanine enrichment in second biopsy - 2H5-phenylalanine enrichment in second biopsy)/ (2H5-phenylalanine plasma enrichment × time)] × 60 × 100. | 9.5 hours |