PhD Program in Space Life Science Functions of Nutrition in Space Scott M. Smith, Ph.D. Nutritionist Manager for Nutritional Biochemistry NASA Johnson Space Center

PhD Program in Space Life Science Nutritional Biochemistry Lab – NASA/JSC  Charge: determine the nutritional requirements for extended duration space flight  Calorie requirements  Vitamin A, E, and D, Calcium, Iron, and Zinc Courtesy of NASA

PhD Program in Space Life Science Functions of Nutrition in Space  Meet energy / nutrient requirements  Psychosocial aspects of the food system  Nutrition as a countermeasure  Changes in the diet to mitigate negative effects of space flight  Importance of defining the nutritional requirements for crews before departure

PhD Program in Space Life Science Concerns: Nutrition in Space Flight  Nutrient Requirements  Energy  CHO (fiber), Fat, Protein  Fat-soluble vitamins  Water-soluble vitamins  Minerals, Fluid  Systems  Bone, Muscle, Cardio Fluid/Electrolyte  Immunology  Hematology, Neurology  Endocrine, Behavioral health & performance, Gastrointestinal  Countermeasures  Energy, Amino acids, Protein, Sodium  Fatty acids  Antioxidants, Vitamin D  Bisphosphonates, K-Citrate  Medications, Exercise  Other  Vehicle/Mission  Food System, Duration  Radiation, extra vehicular activity  Schedule

PhD Program in Space Life Science  Food intake is one of the primary challenges in space  Dietary intake across the space programs  Percent of World Health Organization predicted energy requirement  Crew members can meet their nutritional requirements through food while in space Energy Adapted from Smith, SM, 2005, 2008 Energy intake across different space programs

PhD Program in Space Life Science  Percent of body weight loss at the end of a mission  Effects of long duration flights:  Excess loss of 10% body mass  Other effects:  Fluid shift  Salt loading  Emesis Energy Each symbol is a difference crew member Adapted from Kloeris, LH, 2007

PhD Program in Space Life Science Question From the Audience Are these weights measured after attempts are made to restore plasma volume to normal levels?

PhD Program in Space Life Science  Percent of body weight loss at the end of a mission  Effects of long duration flights:  Excess loss of 10% body mass  Other effects:  Fluid shift  Salt loading  Emesis Energy Each symbol is a difference crew member Adapted from Kloeris, LH, 2007

PhD Program in Space Life Science  Likely consequences of poor food intake  Fair/poor function of cardiovascular system  Loss of muscle mass  Loss of bone mass  NTX (urinary N- telopeptide)  PICP (serum type I procollagen carboxy- terminal propeptide)  OC (plasma osteocalcin) Reproduced from J Bone Miner Res 2004;19: with permission of the American Society for Bone and Mineral Research Energy

PhD Program in Space Life Science Dietary intake record using Food Frequency Questionnaire Courtesy of NASA Food Frequency Questionnaire Energy: Case Study Adapted from Smith, SM, 2005

PhD Program in Space Life Science Consortium for Research in Elder Self-Neglect (SN) of Texas (CREST) Study  25 (OH) Vitamin D  Elderly individuals  Average age: 77 years  Consequences of poor Vitamin D intake below 25 nmol/L  Rickets, Osteomalacia  U.S. Astronauts  Pre and Post flight  4-6 months on board ISS  Increased incidence of disease between nmol/L Elderly Individuals Astronauts Adapted from Smith, SM, 2005, 2006

PhD Program in Space Life Science  Parathyroid Hormone (PTH) is normalized when Vitamin D is above 80 nmol/L  The higher Vitamin D the lower the PTH levels Bone and Beyond Reproduced from New England Journal of Medicine. 338(12): , Copyright © Massachusetts Medical Society. All rights reserved.

PhD Program in Space Life Science Bone and Beyond  Vitamin D status has been related to:  Fracture risk and Bone Mineral Density  Muscle strength/function, falls  Cancer (prostate, breast, colon)  Multiple sclerosis  Blood pressure/heart disease  Diabetes (type 1)

PhD Program in Space Life Science Recommendations  Optimal Vitamin D status:  25D levels ≥ 80 nmol/L  Vitamin D sources:  Foods  Fortified milk, orange juice  Fish (e.g., salmon, tilapia, tuna)  Few other sources of Vitamin D  Sunlight  UV conversion of 7- dehydrocholesterol to previtamin D3 in the skin  Supplements

PhD Program in Space Life Science Antarctica Courtesy of NASA Polar Vitamin D Study in Antarctica  Blind supplementation study  4 groups in the study - randomized:  400 IU Vit. D  1000 IU Vit. D  2000 IU Vit. D  Individuals who  did not take the supplements but provided samples or  took their own Vit. D supplements

PhD Program in Space Life Science Courtesy of NASA Credit:: NASA  Hyperresorptive bone loss  Running on the treadmill does nothing for bone health in space  Nutrition is a countermeasure against bone loss Bone Loss in Space

PhD Program in Space Life Science Nutrition and Bone  Dietary protein has a significant impact on bone health  Higher ratio of animal protein to potassium in the diet provide more acid precursors  An increased ratio leads to more bone breakdown  NTX (N-telopeptide)  APro/K (ratio of animal protein intake to potassium intake) Courtesy of NASA Adapted from Zwart, SR, 2004

PhD Program in Space Life Science Nutrition and Bone  Pilot Study: Antioxidant countermeasure to mitigate oxidative damage  Treatment: Grape juice, Vitamin E & 0.5 mg NAC every day for 2 weeks  N-acetylcysteine (NAC) contains cysteine, a sulfur containing amino acid  Metabolism increases acid load which affects bone  N-telopeptide (NTX) - marker of bone resorption  50% increased excretion in bed rest subjects, 100% increased excretion for astronauts  6 subjects – healthy astronauts  2 weeks placebo: no change in N-telopeptide  2 weeks: Grape juice, Vitamin E & 0.5 mg NAC/day  Increased excretion of bone markers identical to bed rest subjects

PhD Program in Space Life Science Nutrition and Bone Courtesy of NASA  Space flight diet is high in sodium  5-8 grams Na/day  C-telopeptide (CTX) – marker of bone breakdown  Low Na+ diet before and during bed rest  ~50% increase in CTX  High Na+ diet during bed rest  Na+ associated with pH  High Na+ load leads to acid that has negative effect on bone Unpublished data, graph not displayed

PhD Program in Space Life Science Nutrition and Bone  Vitamin K influence on bone  Related to synthesis of gamma-carboxyglutamic acid residues in proteins  Estimated by measuring Vit. K status - undercarboxylated osteocalcin (Uosteocalcin)  Vit. K = Uosteocalcin Courtesy of NASA Adapted from Vermeer, C, 2004

PhD Program in Space Life Science Nutrition and Bone  European Data on MIR  1 astronaut before and after flight  After 85 days Uosteocalcin goes up without supplementation of Vit. K  With Vit. K supplementation Uosteocalcin goes down.  Omega-3 fatty acids  Sources: spinach, salmon  Relationship between omega- 3’s and bone  Could mitigate cancer risk, muscle loss and bone loss Courtesy of NASA Adapted from Vermeer, C, 2004

PhD Program in Space Life Science Courtesy of NASA Credit: NASA  Iron storage increases during flight  Urinary 8-hydroxy guanosine  marker for oxidative damage to DNA  Increased after flight and NEEMO  Radiation/oxygen issues have implications for cataracts and other health issues. Iron and Oxygen Adapted from Smith, SM, 2004 Adapted from Smith, SM, 2001, 2004

PhD Program in Space Life Science Unpublished data not displayed Courtesy of NASA The more total body iron the more oxidative damage Iron and Oxidative Damage

PhD Program in Space Life Science Courtesy of NASA  Changes in iron metabolism during bed rest.  Transferrin receptors go down during bed rest suggesting excess iron  Total body iron vs. 8(OH)dG Unpublished data not displayed Bed Rest

PhD Program in Space Life Science NEEMO – oxidative damage Courtesy of NASA  NEEMO analogue  Hyperbaric environment  Total body iron increases  Malonaldehyde increases – marker of oxidative damage  Inverse relationship between total body iron and SOD – seen with iron overload  Iron excess is related to oxidative damage. Adapted from Zwart, SR, 2008

PhD Program in Space Life Science Courtesy of NASA Space Suit  Peggy Whitson - extra vehicular activity (EVA) suit  Provides thermal protection  Reduced pressure environment

PhD Program in Space Life Science Courtesy of NASA First Blood & Urine Samples on ISS  Vitamin D levels before & after flight  Flight day 15 to flight day 80 – levels hold  800 IU/day of Vitamin D is recommended Unpublished data not displayed

PhD Program in Space Life Science Courtesy of NASA Cape Canaveral – Kennedy Space Center