Nutritional Status Assessment (Nutrition) is a comprehensive in-flight study designed to understand changes in human physiology during long-duration space flight. This study includes measures of bone metabolism, oxidative damage, and chemistry and hormonal changes; as well as assessments of the nutritional status of the crewmembers participating in the study. The results have an impact on the definition of nutritional requirements and development of food systems for future exploration missions to the Moon and Mars. This experiment also helps researchers understand the effectiveness of measures taken to counteract the effects of space flight, as well as the impact of exercise and pharmaceutical countermeasures on nutritional status and nutrient requirements for crewmembers.Principal Investigator(s)
Johnson Space Center, Human Research Program, Houston, TX, United States
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)Research Benefits
Information PendingISS Expedition Duration:
September 2006 - September 2013Expeditions Assigned
14,15,16,17,18,19/20,21/22,23/24,25/26,27/28,29/30,31/32,33/34,35/36Previous ISS Missions
A subset of this protocol, Clinical Nutritional Status Assessment Medical Requirement, has been performed on two Mir missions and on all ISS Expeditions.
Nutrition is critical for health both on Earth and on board the International Space Station. From the time the first crew lived on station up until now, the Clinical Nutritional Assessment profile is implemented to evaluate crew health before and after these 4- to 6-month missions. This clinical protocol nominally consists of two preflight and two postflight evaluations of nutritional status (largely through analysis of blood and urine samples), as well as an in-flight assessment of dietary intake using a Food Frequency Questionnaire. The Nutrition experiment sought to expand the medical requirement testing by including in-flight blood and urine collections and by expanding the nominal testing to include additional normative markers of nutritional assessment.
Until 2006, it was not possible to conduct this type of study during ISS flights because blood and urine could not be collected, stowed frozen, and returned. The altered status of several nutrients after flight was worthy of concern, and alleviating that concern requires the ability to monitor the status of these nutrients during flight. This helps investigators determine if there is a specific impetus or timeframe for these decrements, which informs the requirements. In addition to allowing better monitoring of crew nutritional status during flight, in-flight sample collection allows better assessment of countermeasure effectiveness over the course of the mission, not just after flight.
Additional markers of bone metabolism (e.g.,helical peptide, OPG, RANKL, IGF-1) are measured to better monitor bone health and countermeasure efficacy. New markers of oxidative damage are measured (8-iso-prostaglandin F2?, protein carbonyls, oxidized and reduced glutathione) to better assess the type of oxidative insults that occur during space flight. The array of nutritional assessment variables expanded to include serum folate, plasma pyridoxal 5'-phosphate, vitamin D binding protein, and homocysteine to better understand changes in folate, vitamin B6, and vitamin D status, and related cardiovascular risk factors; respectively, during and after flight. Additionally, stress hormones and hormones that affect bone and muscle metabolism (DHEA, DHEA-S, cortisol, C-reactive protein, testosterone, estradiol) will be measured. This additional assessment provides better health monitoring and allows more accurate recommendations for crew rehabilitation to be made. These variables were added to follow the recommendations of an extramural panel that met to define nutritional standards and requirements in 2005.
The protocol comprises these steps:
The inclusion of in-flight blood and urine collections, and expansion to include additional variables to better monitor nutritional status, are required in order to better understand the role of nutrition in bone health, changes in body composition, oxidative damage, and to better define nutritional requirements for space flight. Maintaining and monitoring nutritional status is important for ensuring crew health during space flight, and is critical as we embark on exploration missions of longer duration in the future.Earth Applications
Increased understanding of the role of nutrition in physiological adaptation to space flight has a broader application on Earth. One example is that understanding the relationship of nutrition to bone loss is potentially valuable for patients suffering from bone loss on Earth.
Sample sessions occur on Flight Days 15 (? 5 days), 30, 60, 120, and 180 (? 14 days). Samples are returned to Earth for analysis within a year of the sampling date.Operational Protocols
During flight, the crew collects blood and 24-h urine samples on the five days designated. The blood samples are processed in the refrigerated centrifuge and then stored in the MELFI. Urine is collected void by void for 24 hours and syringe aliquot samples are stored in the MELFI.
This experiment is still ongoing; urine and blood samples for several astronauts have been collected before, during and after ISS Expeditions. Since the experiment design calls for the combination and comparative analysis of data from all Expeditions, final results are not yet available. Preliminary results have been presented, reviewed, and published in multiple forums(Evans et al. 2009) . Operationally, the data have been valuable in troubleshooting the Urine Processing Assembly (UPA) after the unit developed problems on orbit in 2009, and also in developing operational plans for using this unit. Vitamin D results from spaceflight and ground-based analog studies led to revised vitamin D supplementation recommendations on ISS, and the results of this experiment have documented the effectiveness of this new dose. The ground-based findings from Antarctic research were cited in the Institute of Medicine?s revision of the recommended dietary intakes for North Americans.
Zwart SR, Kloeris VA, Heer MA, Smith SM. Nutritional Biochemistry of Space Flight.. Happauge, NY: Nutritional Biochemistry of Space Flight; 2009.
Zwart SR, Kala G, Smith SM. Body iron stores and oxidative damage increased after a 10- to 12-day undersea dive in humans. Journal of Nutrition. 2009; 139: 90-95.
Mehta SK, Zwart SR, Pierson DL, Gonda S, Smith SM. Capacity of Omega-3 Fatty Acids or Eicosapentaenoic Acid to Counteract Weightlessness-Induced Bone Loss by Inhibiting NF-şB Activation: From Cells to Bed Rest to Astronauts. Journal of Bone and Mineral Research. 2009; 0.