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), 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
2. how much protein do we need – and when ?
3. reconciling current protein recommendations
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
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
Timing of Protein and Exercise
Meal
Whey Protein
Amino Acids
Intact Proteins
(beef, fish etc.)
Appearance in plasma
Peak anabolic window
10-20 minutes
Consume 0-60 minutes post exercise
90 + minutes
Consume approx.. 60-90 minutes before
exercise
* note, the timing relates only to muscle protein anabolism and does not take
into account practical issues such as exercise performance, satiety, gastric
comfort, hunger or coingestion of other nutrients.
Research “hot topic” - Leucine
Leucine Content of Foods
1 scoop (36 g) of whey protein
isolate
3.2 g
1 scoop (36 g) soy protein isolate
2.4 g
4 oz. sirloin steak
2.0 g
4 oz. chicken breast
2.0 g
1 cup low-fat yogurt
1.1 g
1 cup fat-free milk
0.8 g
1 egg
0.5 g
2 tbsp. peanut butter
0.5 g
1 slice wheat bread
0.1 g
Sources: USDA National Nutrient Database for Standard Reference, Release 20. and GNC WPI 28
3. Reconciling current protein recommendations
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 and protein distribution
Effective
exercise?
Catabolism Anabolism
maximum rate of protein synthesis
10 g
15 g
65 g
Total Protein
90 g
Exercise 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
Are our older inpatients eating enough ?
Presented
grams
100
Consumed
80
60
40
20
0
Protein
Carbohydrate
per meal
Paddon-Jones, pilot data
Fat
High simple sugar desserts
accounted for 50% of the protein
consumed by inpatients
Delicious ? …maybe…. Healthy ?.... not so much
5. Sarcopenia and a new approach to interventions
SARCOPENIA
o Decline in basal energy expenditure
o Reduced insulin sensitivity
o Reduced muscle strength
o Reduced physical performance
o Increased risk for falls
o Increased health-related expenses
o Increased morbidity
o Increased mortality
Adapted from: Dr. OMAR JALUUL
Fried LP, Hadley EC, Walston JD, et al. 2005.
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)
Holloszy, Mayo Clin Proc. 2000
60
70
80
5
20 30 40 50 60 70 80
Age (years)
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
Protein and Renal Function
Institute of Medicine:
“protein content of diet is not
related to progressive decline
in kidney function with age."