Dairy protein and muscle strength

Dairy protein and muscle
strength;
Implications for fall prevention.
Dr David CameronCameron-Smith
Senior Lecturer
School of Exercise and Nutrition Sciences
Deakin University
1
2
Influence of age on muscle mass
Men
Women
25 year old man
Muscle Mass (kg)
50
40
30
65 year old man
20
10
0
15
25
35
45
55
65
75
85
Age (years)
3
4
Janssen et al., J Appl Physiol 89:81-88, 2000
Association between severe sarcopenia
and physical function in older women
Longitudinal changes in muscle mass
Walk 1/4 Mile
Quadriceps CSA (cm2)
65
Climb 10 Stairs
60
55
Lift 10 lbs
50
Walk 8 Feet
45
40
5 Chair Stands
35
Personal Care Needs
30
25
Preparing Meals
20
1982
(x = 74 yr)
1990
Performing Chores
(x = 82 yr)
0
1
2
3
4
5
6
7
8
9
10
11
Adjusted Odds Ratio (95% CI)
C.A. Grieg et al., Muscle & Nerve 1993;16:6-10
5
(Normal Muscle used as Referent Group)
Janssen et al., J Am Geriatr Soc 50:889-896, 2002
6
Vicious Cycle of Sarcopenia
No loss of fibre strength with age
1.2
1
0.8
YM
*
*
0.6
0.4
YW
OM
OW
0.2
0
Type 1
7
Type 2
Trappe S et al J. Physiol. 552: 47-58, 2003.
8
Skeletal Muscle
Muscle plasticity
9
10
Multinucleated myofibres
Newlands S. et al. Genes & Development 12: 2748-2758, 1998
11
Hawke & Garry J App Physiol. 91: 534-551,
2001.
12
Muscle recovery following cardiotoxin
exposure
13
14
Garry DJ et al PNAS 97: 5416-21, 2000
Zoico et al (2002). Nutrition Reviews 60: 39-51
The Interplay Between Chronic
Inflammation & Acute Phase Response
As yet there is no
data that
demonstrates
whether
supplemental
protein ingestion,
following
eccentric exercise
is able to
favourably impact
on the chronic and
acuteacute-phase
0.100
Gene expression
normalised to GAPDH
„
Muscle Inflammation & Dairy Protein
c-c-fos
fos
^
Placebo
Whey
BLG
*
0.075
0.050
#
0.025
0.000
Pre
2h
4h
24 h
* denotes a significant difference (P<0.05) in the Placebo group between the pre and 2hr time point.
^ denotes a significant difference (P<0.05) between the Placebo and BLG group at the 2hr time point.
# denotes a significant difference (P<0.05) in the BLG group between the pre and 2hr time potnt.
15
Myogenic Regulatory Factors (MRFs
(MRFs)) &
Growth Factors
Mathers et al, Unpublished
Myogenic Regulatory Factors (MRFs
(MRFs)) &
Growth Factors
17
Charge & Rudnicki. Physiol. Rev. 84: 209-38, 2004.
16
18
Charge & Rudnicki. Physiol. Rev. 84: 209-38, 2004.
Myogenic Factors and Dairy Protein
MyoD D
Myo
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
Placebo
BLG
Placebo
Whey
Myogenin
Myogenin
Growth Factor Signalling Pathways
Placebo
BLG
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
pre
2h
4h
24 h
Pre
2h
4h
24 h
Carey et al, Unpublished data
19
Glass D. Nature Cell Biology 5: 87 - 90, 2003.
20
Muscle Biopsies
21
2. Reduced Proliferative Potential
1. Reductions in satellite cell number
Kadi et al, Muscle & Nerve 29: 120-27, 2004
22
23
Bortoli et al Gene 321; 145-154, 2003.
24
Acute MyoD Response in Older
Humans
Hameed et al. J. Physiol. 547: 247-54, 2002.
Genetic basis of impaired proliferation is
poorly understood
25
Protein Synthesis – PostPost-Exercise
Sheffield-Moore et al. Am. J. Physiol. Endo. Metab. 287:E513-E522, 2004
26
Protein Breakdown – PostPost-Exercise
27
Sheffield-Moore et al. Am. J. Physiol. Endo. Metab. 287:E513-E522, 2004
28
Myostatin Function
Muscle Atrophy Gene - Myostatin
Shuelke et al. New Eng J. Med. 350; 2682-88, 2004
Bortoli et al. Gene 321; 145-154, 2003.
29
30
McNally New Eng J Med 350: 2642-43, 2004
Myostatin mRNA response to resistance
exercise
Atrogenic Pathway
Myostatin
mRNA expression relative to
b-actin
0.025
0.020
0.015
**
0.010
**
0.005
0.000
pre
30min
4h
24h
31
32
Carey et al, Unpublished data
AtroginAtrogin-1 and MURFMURF-1
Strength Gains in 12 Weeks
0.005
mRNA expression relative to
b-actin
mRNA expression relative to
b-actin
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
MURF-1
pre
30min
4h
24h
0.004
0.003
0.002
0.001
0.000
pre
30min
4h
24h
Increase in Peak Torque Strength (%)
50
Atrogin-1
45
40
Concentric
Eccentric
35
30
25
20
15
10
5
0
Older Adult
33
Exercise training in the very old: 85+yrs
Younger Adult
34
Farnfield et al, Unpublished Data
CrossCross-over between exercise and
protein availability
Resistance Exercise
activation
S6K1 - P
4E-BP1-P
Protein
synthesis
Fiatrone MA et al New Eng. J. Med. 330: 1769-75, 1994
35
Leucine
+
+
S6K1
4E-BP1
Protein
CSA
MHC
36
Leucine Comparisons
Leucine (mg/g protein)
136
104
104
96
170
106
95
120
nitrogen (mmoles)
Protein Source
b-Lactoglobulin
lactalbumin
BSA
Immunoglobulins
GMP
Lactoferrin
Casein
Fast versus slow
100
whey protein
casein
80
60
40
20
0
0
40
80
120
Time (min)
160
37
Harper WJ, 2000
Older males – Impact of Timing
38
Changes in Muscle Characteristics
Immediate
2hours after
Esmark et al. J. Physiol. 535: 301-311, 2001
39
Esmark et al. J. Physiol. 535: 301-311, 2001
40
In bodybuilders…
In young males?
The effect of VP2 whey isolate, micronized creatine and resistance
training on fibre characteristics, strength and body composition
11 week intervention in resistancetrained men.
Strength gains (1RM max)
Creatine/carbohydate 284%
Whey isolate
308%
Creatine/Whey isolate 371%
versus placebo
Type 2 muscle fibre area
Creatine/carbohydate
793%
Whey isolate
543%
Creatine/Whey isolate 1230%
versus placebo
Burke et al. Int. J. Sport Nutr. Exerc. Metab. 11: 349-64, 2001
41
Cribb et al 2003 Experimental
42
Biology meeting
Size
Strength
Clinical evidence
CSA
Structural proteins
THAT’S IT FOLKS!!
Translation initiation
Signalling protein activation
Growth factor activation
Myogenic/Atrogenic Genes
Fundamental & mechanistic
evidence
AA blood response
AA composition
Nutritional Basis
Exercise
Stimulus
43
Thanks
45
Pre-clinical evidence
Dairy
Protein
Young
& Old
44