Maintaining Muscle Mass in Older Adults
Nutrition and Exercise Strategies
Douglas Paddon-Jones, Ph.D.
Professor, Nutrition and Metabolism
The University of Texas Medical Branch
Disclosures
 Dr. Paddon-Jones is a Research Investigator with funding
from the National Institute of Health (NIH), the Dairy
Research Institute and the National Space Biomedical
Research Institute (NSBRI).
 Dr. Paddon-Jones is a member of the Scientific Advisory
Board or Speaker’s Bureau for the National Dairy Council,
US Dairy Export Council, American Egg Board, Texas Beef
Council and Abbott Nutrition.
Overview
1. building muscle in response to protein: young vs. elderly
2. how much protein do older adults need – and when ?
3. protein distribution and daily requirements
4. priority areas: what happens if you are injured or sick?
5. sarcopenia and a new approach to interventions
Maintaining Muscle Mass and Function
Synthesis
Muscle
growth
Hormones
Exercise
Nutrition
Protein
Balance
Malnutrition
Breakdown
Inactivity
Illness/Injury
Muscle
loss
Stable Isotope Methodology (ring - 13C6
Artery
Synthesis
Breakdown
Vein
- Phenylalanine)
1. Building muscle in response to protein
Protein Synthesis (%/h)
Stimulating Muscle Growth with Protein
0.14
*
0.12
0.1
*
50% increase
0.08
Young
Elderly
0.06
0.04
0.02
0
Fasting
Symons et. al. AJCN, 2007
30 g protein
2. How much protein do we need – and when ?
How much protein do we need ?
- a message of moderation -
30 g protein
Protein Synthesis (%/h)
0.14
*
0.12
90 g protein
*
*
*
0.1
0.08
0.06
0.04
Young
Old
0.02
0
Fasting
30 g protein
Fasting
90 g protein
~1.2 g/kg/day for 75kg individual
Symons et. al. AJCN, 2007
Symons et. al. JADA. 2009
Key points
Protein Synthesis (%/h)
0.18
No age-related
impairment
0.16
0.14
*
0.12
*
0.1
0.08
0.06
0.04
0.02
0
Fasting
Symons et. al. AJCN, 2007
Moderate protein meal
Age-related dose-response
Net Muscle Protein Synthesis
(mg Phe/leg)
60
6g
50
Young
40
Elderly
5g
30
20
8g
10
0
Katsanos et. al. AJCN, 2005
More than ~25 g protein
Less than ~15 g protein
6g
Protein + Exercise
+
Additive Effect of Protein and Exercise
0.18
*
*
0.16
Protein Synthesis (%/h)
0.14
100% increase
0.12
0.1
*
*
50% increase
Young
Elderly
0.08
0.06
0.04
0.02
0
Fasting
Symons et. al. JNHA, 2010
Protein meal
Protein + Exercise
3. Protein distribution and recommendations
How Much Protein Do We Eat?
HIGH PROTEIN
DIETS
Protein consumed in Australia (grams per day)
Males
19-30y
31-49y
50-69y
70+y
Females
19-30y
31-49y
50-69y
70+y
5th %
77
79
63
50th %
115
107
96
95th %
186
155
144
…good thing I moved
47
50
47
38
Source : NNS 95 (M. Noakes)
74
73
70
61
120
107
101
95
Daily protein distribution
- typical ? -
Catabolism Anabolism
maximum rate of protein synthesis
10 g
15 g
65 g
Total Protein
90 g
~ 1.3 g/kg/day
A skewed daily protein distribution fails
to maximize potential for muscle growth
Paddon-Jones and Rasmussen 2009
Daily protein distribution
- typical ? -
Catabolism Anabolism
maximum rate of protein synthesis
10 g
15 g
65 g
X
Total Protein
90 g
 30 g
Usable Protein
55 g
~ 0.7 g/kg/day
A skewed daily protein distribution fails
to maximize potential for muscle growth
Paddon-Jones and Rasmussen 2009
Daily protein distribution
- Optimal -
Catabolism Anabolism
maximum rate of protein synthesis
30 g
30g
30 g
Total Protein
90 g
Usable Protein
90 g
~ 1.3 g/kg/day
Repeated maximal stimulation of protein synthesis
 increase / maintenance of muscle mass
Paddon-Jones and Rasmussen 2009
Exercise/Rehabilitation and Protein Distribution
Effective
exercise?
Catabolism Anabolism
maximum rate of protein synthesis
10 g
15 g
65 g
Total Protein
90 g
Exercise/Rehabilitation and Protein Distribution
Effective
exercise
Catabolism Anabolism
maximum rate of protein synthesis
30 g
30g
30 g
Total Protein
90 g
4. priority areas: dealing with injury or illness
Bed rest is a defacto treatment modality
- if you’re hospitalized you become inactive -
100
% of
Time
90
80
70
60
50
40
30
20
10
0
Inactive
(0 steps/min)
Low Activity
(< 15 steps/min)
Inactivity and Aging Muscle
Loss of lean leg mass (g)
250
Healthy Young
28 Days Inactivity
Healthy Elders
10 Days Inactivity
0
-250
3 times more
muscle loss
-500
1/3 the time
-750
2%
total lean leg mass
All volunteers
consumed the
RDA for protein
-1000
-1500
-2000
10%
total lean leg mass
Paddon-Jones et. al. 2004
Kortebein et al. 2007
Inactivity reduces muscle protein synthesis
Protein Synthesis (%/h)
0.1
0.09
0.08
0.07
*
0.06
30%
0.05
0.04
0.03
0.02
0.01
0
Day 1
Day 10
24 h muscle protein synthesis during 10 day of inactivity in elders
(stable isotope methodology)
Kortebein et al. 2007
Protein combats muscle loss during inactivity
Protein Synthesis (%/h)
0.1
Day 1
Day 10
- older adults -
0.09
#
0.08
0.07
*
0.06
30%
0.05
0.04
0.03
0.02
0.01
0
Normal Diet
Normal Diet +
Amino Acids
Normal Diet
Normal Diet +
Amino Acids
Ferrando & Paddon-Jones et. al. 2009
Muscle Loss in Hospitalized Older Adults
250
Loss of lean leg mass (g)
Healthy Young
28 Days Inactivity
Healthy Elders
10 Days Inactivity
Elderly Inpatients
3 days hospitalization
0
-250
-500
-750
-1000
-1500
2%
total lean leg mass
-2000
10%
total lean leg mass
10+ %
total lean leg mass
Paddon-Jones , Pilot Data
5. Sarcopenia and a new approach to interventions
Sarcopenia: - definitions Fat Mass
Lean Body Mass
55
35
30
45
(kg)
(kg)
50
40
20
15
35
30
25
10
20
30
40
50
Age (years)
60
70
80
5
20 30 40 50 60 70 80
Age (years)
……a syndrome characterized by progressive and generalized loss of
skeletal muscle mass and strength with a risk of adverse outcomes
such as physical disability and poor quality of life.
Holloszy, Mayo Clin Proc. 2000
Alternate model of muscle loss
- developing tactical nutrition interventions -
Lean muscle mass (kg)
31
29
27
25
23
21
19
17
15
40 44 48 52 56 60 64 68 72 76 80 84 88
Age (yrs)
Prevention and treatment strategies
PREVENTION:
 Adopt a meal-based approach to protein consumption
 Consume a moderate amount of high-quality protein,
3-times per day
 Consume protein in close proximity to exercise
Prevention and treatment strategies
TREATMENT:
React aggressively with nutritional support
to reduce the rapid loss of muscle and strength
associated with physical inactivity, illness or injury
Emily Arentson-Lantz, Ph.D.
Fellow
Kirk English
Doctoral Student
Joni Mettler, Ph.D.
Assistant Professor, TSU
Barbara Doucet, OT., Ph.D
Assistant Professor
Christopher Danesi
Coordinator