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Dietary protein, muscle and health: beyond the guidelines Douglas Paddon-Jones, Ph.D., FACSM Department of Nutrition and Metabolism The University of Texas Medical Branch Conceptual Model….. Inactivity Disease Inadequate Nutrition Aging Blood Flow Drug therapies Mitochondrial Dysfunction Activity Inflammation Stable Isotope Methodology (ring - 13C6 - Phenylalanine) Artery Synthesis Breakdown Vein How much protein – need, want or desire… ? Interpreting Protein Recommendations RDA: “estimate of the minimum daily average dietary intake level that meets the nutrient requirements of 97-98% of healthy individuals” High Risk RDA for protein: 0.8 g of good quality protein / kg body weight / day Low Risk Low EAR RDA Moderate High Protein Consumption Excessive Dietary protein and bone • Moderate protein diet (1- 1.5 g/kg/day) normal calcium metabolism • Low protein intakes ( 0.8 g/kg/day): - reduced intestinal calcium absorption - increased parathyroid hormone - release of calcium from bone Feskanich D, et al. Am J Epidemiol 1996;143:472-9. Cooper C, et al. Calcif Tissue Int 1996;58:320-25 Protein and renal function Institute of Medicine: “protein content of diet is not related to progressive decline in kidney function with age." Complete vs. incomplete protein and biological value Protein digestibility and biological value DIAAS vs. PDCAAS (2013) (1989) Paul Moughan – Massey Hans Stein - Illinois Key concept: limiting amino acids Limiting amino acids: - methionine & cysteine - lysine (soy) - methionine / tryptophan ( * quantity?) - lysine + methionine + + lysine - methionine = Reality Check / Reminder: Low protein quality ≠ Poor nutritional quality (…...not all the time anyway) Single source protein supplements: Clinical / Practical Relevance ? Whey Casein Soy Blends Milk protein Collagen ( - tryptophan) Rice ( - lysine) Pea ( - methionine + cysteine) Anabolic response to “whole-food” protein 4 oz Beef Protein Synthesis (%/h) 0.14 * 0.12 12 oz Beef * * * 0.1 0.08 0.06 0.04 Young Old 0.02 0 Fasting 30 g protein Fasting 90 g protein References: Symons et. al. AJCN, 2007 Symons et. al. JADA. 2009 Synergistic 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 Protein meal Protein + Exercise Reference: Symons et. al. JNHA, 2010 Reality: Age-related dose-response Net Muscle Protein Synthesis (mg Phe/leg) 60 6g 50 Young 40 Elderly 5g 30 20 8g 10 0 More than ~25 g protein Less than ~15 g protein 6g Reference: Katsanos et. al. AJCN, 2005 Protein timing and distribution Typical US protein consumption pattern 45 Protein consumed per meal (g) 40 average: 60-100 g protein/day (~1.0 g /kg/day) 35 30 25 20 15 10 5 0 Breakfast Lunch Dinner National Health and Nutrition Examination Survey (NHANES) Snacks Fulgoni AJCN 2008 Katsanos et. al. AJCN, 2005 Symons et. al. AJCN, 2007 Symons et. al. JADA. 2009 We can’t store excess protein for later anabolism Catabolism Anabolism maximum rate of protein synthesis Total Protein 90 g 10 g 15 g X 65 g 30 g Usable Protein 55 g ? ~ 0.7 g/kg/day ? Reference: Paddon-Jones and Rasmussen 2009 Concept: Optimizing protein at each meal ? Catabolism Anabolism maximum rate of protein synthesis 30 g 30 g 30 g Total Total Protein Protein 90 gg ? ~ 120 Usable Protein 90 g ? ~ 1.3 g/kg/day greater 24 h protein synthesis response ? Reference: Paddon-Jones and Rasmussen 2009 Protein distribution impacts muscle protein synthesis 25% * * 30 - 30 - 30 g 10 - 15 - 65 g Older (?) Reference: Mamerow, et.al. J. Nutr. 2014 Building and Losing Muscle protein & amino acids If you are hospitalized - you are put in bed 100 90 80 % Time 70 60 50 40 30 20 10 0 Inactive (0 steps/min) Low Activity (< 15 steps/min) Inactivity and Muscle Loss Loss of lean leg mass (g) - Bed Rest - Young Middle-aged Older Older Patients 28 Days 14 Days 10 Days 4 Days 0 -250 -500 -750 -1000 -1500 |-------------------- best case situation----------------------| -2000 Paddon-Jones et. al. 2004 English et al., 2014 Kortebein et al. 2007 Paddon-Jones , Pilot Data What do older inpatients eat ? Presented grams 100 Consumed 80 60 40 20 0 Protein Carbohydrate per meal Paddon-Jones, pilot data Fat Protecting Muscle with Nutrition Leucine has a key regulatory role on muscle protein synthesis …are the benefits overstated ? Leucine: partially protects muscle function Knee extension endurance Aerobic capacity (VO2max) Knee extension strength/torque Percentage change % 0 -5 -10 -15 -20 Control Leucine English, et al. 2015 AJCN Leucine: partially / temporarily protects muscle mass Day 7 (mid-point) Day 14 (end bed rest) Whole body lean mass (g) 0 -250 -500 -750 -1000 -1250 Control Leucine English, et al. 2015 AJCN Smaller protein meal + leucine Clinical relevance ? Young Net Muscle Protein Synthesis (mg Phe/leg) 60 Elderly 50 40 30 10 g 20 3g 10 0 More than ~25 g protein Less than ~15 g protein protein + leucine Leucine content of food Protein source Leucine whey protein isolate 13 % milk protein 10 % egg protein 8.5 % muscle protein 8% soy protein isolate 8% wheat protein 7% collagen 2% Amino Acid Composition of Whey Protein 25 g / 100 g 20 15 10 5 0 His Lys Me Phe t Iso Leu Val Th Whey Asp Ser Gln Pro Human muscle Gly Ala Ty Arg Summary and recommendations Summary Protein quality – don’t over complicate it Combinations, quantities and common sense Mechanism-focused studies provide direction and highlight potential Current dietary practices: obstacles and opportunities Protein/leucine: meal distribution, dose response, ceiling effects? Recommendations For all adults…. Establish a dietary framework that includes a moderate amount of high quality protein (or combination) at each meal. Modify as necessary to accommodate individual needs: - energy requirements - physical activity - health status - body composition goals - dentition, satiety Recommendations React aggressively with targeted protein / nutrition interventions to preserve normal protein turnover and reduce negative metabolic consequences of short-term physical inactivity, illness or injury Paddon-Jones Lab • Emily Arentson-Lantz • Jennifer Ellison • Elfego Galvan Colleagues • ITS-CRC Nursing & Bionutrition Staff • Blake Rasmussen • Wayne Campbell • Don Layman • Thomas Lang • Aaron Russell / Severine Lamon Funding • RO1 NR012973 • R21 AR062479 • NSBRI (NNJ08ZSA002N) • National Dairy Council • Texas Space Grant Consortium • UTMB Claude D. Pepper Older Americans Independence Center (NIH) Medical Team • Adam Wacher • Elena Volpi • James Pattarini • Charles Mathers