Protein & Healthy Aging: Challenging Current Recommendations Douglas Paddon-Jones, Ph.D., FACSM Sheriden Lorenz Distinguished Professor of Aging and Health Department of Nutrition and Metabolism, Center for Recovery, Physical Activity and Nutrition University of Texas Medical Branch, Galveston, TX, USA Disclosures I have received funding, participated on a Scientific Advisory Board or Speaker s Bureau for: National Dairy Council US Dairy Export Council American Egg Board National Cattlemens Beef Association Abbott Nutrition Agropur Leprino Foods Sabra Wellness National Space Biomedical Research Institute 1
Outline Inactivity Disease Inflammation Mitochondrial Dysfunction Inadequate Nutrition Aging Activity Pharmacology Perfusion How much protein do we need? + when, why, how and who. 2
Recommended Dietary Allowance (RDA).8 g protein / kg bodyweight / day The minimum daily average dietary intake level..[of good quality protein ]..that meets the nutrient requirements of 97 98% of healthy individuals.prescription? Position Statements: highly active adults Protein intake should be increased in highly active people: 1.2-1.7 g/kg/day ACSM/ADA/DC Position, MSSE, 29 3
If the RDA defines the minimum protein intake is there a maximum? IOM / FNB: No Tolerable Upper Intake Level AMDR: Up to 35% of daily energy (~ 22 g protein / day) permission to go crazy How Much Protein Do We Eat? National Health and Nutrition Examination Survey (NHANES) Protein consumed per meal (g) 45 4 35 3 25 2 15 1 5 Total: ~ 88 g/day (~1.2 g protein/kg/day) Breakfast Lunch Dinner Snacks 4
How much protein per meal do we need? - a message of moderation - 3 g protein 9 g protein Protein Synthesis (%/h).14.12.1.8.6.4.2 * * * * Young Old Fasting 3 g protein Fasting 9 g protein References: Symons et. al. AJCN, 27 Symons et. al. JADA. 29 Synergistic Effect of Protein and Exercise.18.16 * * Protein Synthesis (%/h).14.12.1.8.6.4 1% increase 5% increase * * Young Elderly.2 Fasting Protein meal Protein + Exercise Reference: Symons et. al. JNHA, 21 5
Reality: Age-related dose-response 6 6 g Net Muscle Protein Synthesis (mg Phe/leg) 5 4 3 2 1 Young Elderly 5 g 8 g More than ~25 g protein Less than ~15 g protein 6 g Reference: Katsanos et. al. AJCN, 25 Protein Quantity and Daily Distribution 6
Concept: Skewed / typical protein intake We can t store excess protein for later anabolism Catabolism Anabolism 1 g 15 g 65 g maximum rate of protein synthesis Total Protein 9 g Usable Protein 55 g? ~ 1.3 g/kg/day Reference: Paddon-Jones and Rasmussen 29 Concept: Optimizing protein at each meal? Catabolism Anabolism 3 g 3 g 3 g maximum rate of protein synthesis Total Protein 9 g Usable Protein 9 g ~ 1.3 g/kg/day greater 24 h protein synthesis response? Reference: Paddon-Jones and Rasmussen 29 7
Protein distribution impacts muscle protein synthesis 25% * * 3-3 - 3 g 1-15 - 65 g Reference: Mamerow, et.al. J. Nutr. 214 Sarcopenia Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life and death. Cruz-Jentoft AJ et al. Sarcopenia: European consensus on definition and diagnosis. Report of the European Working Group on Sarcopenia in Older People. Age Ageing 21 8
Catabolic crisis model 31 29 Muscle mass (kg) 27 25 23 21 19 17 15 4 44 48 52 56 6 64 68 72 76 8 84 88 Age (y) Reference : English and Paddon-Jones. Curr Opin Clin Nutr Metab Care. 21 Bed rest / disuse in clinical settings % Time 1 9 8 7 6 5 4 3 2 1 Inactive ( steps/min) Low Activity (< 15 steps/min) Nutrition and Metabolism 9
Inactivity and Muscle Loss - Bed Rest - Young Middle-aged Older Older Patients Loss of lean leg mass (g) -25-5 -75-1 -15-2 28 Days 14 Days 1 Days -------------------- best case situation---------------------- 4 Days Paddon-Jones et. al. 24 English et al., 214 Kortebein et al. 27 Paddon-Jones, Pilot Data Disuse inactivity: age and sex-specificity Disuse Rehabilitation - Middle-age Older - Middle-age Older Change in lean leg mass (g) -25 - -5 - -75 - -1 - -125 - -15 - a. - - - - - - b. Men Women -175 - - Paddon-Jones et. al. 24 English, English et al. et al., 215 214AJCN + Kortebein new prelim et al. data 27 Paddon-Jones, Pilot Data 1
Pragmatic approach: efficiency and protein quality Efficiency is critical Protein Quality Leucine has a key regulatory role on muscle protein synthesis are the benefits overstated? Healthy vs. Clinical? Leucine (4 g/meal): partially protects muscle function Muscle endurance Aerobic capacity Muscle strength Percentage change % -5-1 -15-2 Note: Testosterone did not protect strength during bed rest Control Leucine Healthy middle-age adults; 14 days bed rest English, et al. 215 AJCN Zachwieja, et al. 1999 JCEM 11
Leucine: partially / temporarily protects muscle mass Day 7 (mid-point) Day 14 (end bed rest) Whole body lean mass (g) -25-5 -75-1 -125 Control Leucine Healthy middle-age adults; 14 days bed rest English, et al. 215 AJCN 12
What is a typical (or achievable) step count for inpatients? Healthy older adults: 14 days reduced activity Sedentary behavior ~ 6, steps / day ~ 1,4 steps / day 4 g leg muscle loss Breen et al., JCEM 213 13
Minimum activity intervention model Healthy older adults (68+2 y) 7 days bed rest ± 2 steps per day 3-day run-in period: 588 ± 189 steps/day Bed rest period: Step count 218 ± 4 steps/day (STEP group) Activity time 22 ± 1 minutes/day 155 ± 8 minutes/week Intensity: 94 ± 4 steps/minute 12 ± 5 bpm (vs. resting: 65 ± 3 bpm) Lean Leg Mass (g) Change in leg lean mass (g) -2-4 -6-8 -1-12 -14 * * CON STEP Bed rest + 2 steps / day 14
Blood glucose AUC (mg/dl/12min) 3 Change in AUC (mg/dl/12min) 2 1-1 CON STEP -2 Bed rest + 2 steps / day Isokinetic torque (nm) also, no effect on aerobic function / muscular endurance Change in isokinetc knee extension torque (Nm) -2-4 -6-8 -1-12 -14-16 -18-2 CON STEPS Bed rest + 2 steps / day 15
Recommendations: Prevention and Treatment For all healthy adults. Establish a dietary framework that includes a moderate amount of high quality protein at each meal. Modify as necessary to accommodate individual needs: - energy requirements - physical activity - health status - body composition goals - dentition, satiety Recommendations: Prevention and Treatment During periods of catabolic crisis:.8 g protein/kg/day is insufficient Blunt addition of protein/energy is inefficient Modest walking alone is not fully protective Aggressive support with high quality protein (whey/leucine) and activity may help preserve muscle health 16
Acknowledgements Emily Arentson-Lantz Elfego Galvan Adam Wacher Elena Volpi Charles Mathers Blake Rasmussen Heather Leidy Wayne Campbell Don Layman Funding RO1 NR12973 R21 AR62479 NSBRI (NNJ8ZSA2N) National Cattlemens Beef Association National Dairy Council UTMB Claude D. Pepper Older Americans Independence Center 17