The Medical Requirement for long-duration crewmembers, Clinical Nutritional Assessment profile (MR016L), has been implemented for all International Space Station (ISS) US crewmembers. The MR016L protocol nominally consists of two preflight and one postflight analysis of nutritional status. The Nutritional Status Assessment (SMO 016E) project sought to expand the MR016L testing in three ways: 1) include in-flight blood and urine collection, 2) expand nominal testing to include additional normative markers of nutritional assessment, and 3) add an R+30 session to allow evaluation of postflight nutrition and implications for rehabilitation.
To date, it has not been possible to assess nutritional status during flight because blood and urine could not be collected/returned during ISS missions. The altered nutritional status findings for several nutrients postflight are of concern, and in order to determine if there is a specific impetus or timeframe for these decrements the ability to monitor the status of these nutrients during flight is required. In addition to monitoring crew nutritional status during flight, in-flight sample collection would allow for better assessment of countermeasure effectiveness. This protocol is also designed to expand the current MR016L to include additional normative markers for assessing crew health and countermeasure effectiveness, and extend the current protocol to include an additional postflight blood and urine collection (R+30). Several nutritional assessment parameters are altered at landing, but it is not known whether the changes are still apparent after 30 days.
Nutritional Status Assessment (AKA Nutrition) is the most comprehensive inflight study done by NASA to date of human physiologic changes during long-duration space flight; this includes measures of bone metabolism, oxidative damage, nutritional assessments, and hormonal changes. This study will impact both the definition of nutritional requirements and development of food systems for future space exploration missions to the Moon and Mars. This experiment will also help to understand the impact of countermeasures (exercise and pharmaceuticals) on nutritional status and nutrient requirements for astronauts.
Blood and two consecutive 24-hour samples were collected approximately 180 and 45 days before launch, and again on landing day and 30 days after landing. Crewmembers provided up to five blood and 24-hour urine collections during space flight at about flight day 15. Except for samples collected on R+0, all blood samples were collected at least eight hours after food intake or exercise. Because flight durations varied, not all crewmembers had five in-flight sessions.
Crewmembers used the interim resistive exercise device (iRED) or the Advanced Resistive Exercise Device (ARED) during space flight. Investigators compared these devices and collected data from two mass measurement devices on the ISS, the Russian Body Mass Measuring Device (BMMD), which uses spring oscillation physics, and NASA's Space Linear Acceleration Mass Measurement Device (SLAMMD).
Astronauts who exercise regularly using resistive exercise coupled with adequate energy intake and vitamin D status can return from space flight missions of four to six months with measured bone mass and bone mineral densities which are very close to their preflight measures for most skeletal regions.
For crewmembers whose body mass was measured on both devices, significant body mass loss occurred compared to preflight and averaged -4.4% as assessed by BMMD and -2.8% as assessed by SLAMMD. After an initial loss in the first 30 days of flight, body mass remained constant through the rest of the mission, as determined using either device. The mean difference between the two devices was 1.1 kg when the closest scheduled SLAMMD and BMMD measurements were compared. Dietary intake during flight is approximately 80% of the World Health Organization's estimated requirement and the decrease in body mass follows in-flight energy intake closely on average.
The bone mineral density response to space flight was the same for men and women in both exercise groups. The typical decrease in bone mineral density after flight was not observed for either sex for those using the ARED. Biochemical markers of bone formation and resorption responded similarly in male and female astronauts. The response of urinary supersaturation risk to space flight was not significantly different between men and women, although risks were typically increased after flight in both groups, and risks were greater in men than in women before and after flight. Thus, the responses of men and women to space flight with respect to these measures of bone health were not different.
The plasma concentrations of 22 cytokines were monitored in astronauts during long-duration space flight onboard the ISS. Blood samples were collected three times before flight, 3–5 times during flight (depending on mission duration), at landing, and 30 days after landing. Analysis was performed by bead array immunoassay. With few exceptions, minimal detectable mean plasma concentrations were observed at baseline for innate inflammatory cytokines or adaptive regulatory cytokines; however, interleukin (IL)-1ra and several chemokines and growth factors were constitutively present. An increase in the plasma concentration, tumor necrosis factor-a (TNFa), IL-8, IL-1ra, thrombopoietin (Tpo), vascular endothelial growth factor (VEGF), C-C motif chemokine ligand 2 (CCL2), chemokine ligand 4/macrophage inhibitory protein 1b (CCL4), and C-X-C motif chemokine 5/epithelial neutrophil-activating protein 78 (CXCL5) was observed associated with space flight.
In-flight data indicate that iron stores increase early in flight then return to preflight concentrations by the end of a six month mission. The increase of ferritin was associated with evidence of oxidative damage and bone resorption. The greater the increase in ferritin during flight, the greater the decrease in BMD in the hip and pelvis after long-duration space flight.
The following publications are available through open access:
Smith SM, Zwart SR, and Heer MA. Human Adaptation to Spaceflight: The Role of Nutrition (NP-2014-10-018-JSC). Houston, TX: National Aeronautics and Space Administration Lyndon B. Johnson Space Center; 2014. (ISBN 978-0-16-092629-7). http://www.nasa.gov/hhp/education
Smith SM, Zwart SR, Kloeris V, and Heer MA. Nutritional Biochemistry of Space Flight. Happauge, NY: Nova Science Publishers, Inc. 2009. (ISBN 978-1-60741-641-8) https://www.novapublishers.com/catalog/product_info.php?products_id=20061
|Mission||Launch/Start Date||Landing/End Date||Duration|
|Expedition 14||09/18/2006||04/21/2007||215 days|
|Expedition 15||04/07/2007||10/21/2007||197 days|
|Expedition 16||10/10/2007||04/19/2008||192 days|
|Expedition 17||04/08/2008||10/23/2008||198 days|
|Expedition 18||10/12/2008||04/17/2009||187 days|
|Expedition 19||03/26/2009||10/11/2009||199 days|
|Expedition 20||05/27/2009||10/11/2009||137 days|
|Expedition 21||10/11/2009||12/01/2009||51 days|
|Expedition 22||11/30/2009||03/18/2010||109 days|
|Expedition 23||03/18/2010||06/01/2010||75 days|
|Expedition 24||06/01/2010||09/25/2010||117 days|
|Expedition 25||09/24/2010||11/25/2010||31 days|
|Expedition 26||11/26/2010||03/16/2011||111 days|
|Expedition 27||03/14/2011||05/23/2011||70 days|
|Expedition 28||05/23/2011||09/15/2011||115 days|
|Expedition 29||09/16/2011||11/21/2011||40 days|
|Expedition 30||11/14/2011||04/27/2012||166 days|
|Expedition 31||04/27/2012||07/01/2012||65 days|
|Expedition 32||07/01/2012||09/16/2012||78 days|
|Expedition 33||09/16/2012||11/18/2012||63 days|
|Expedition 34||11/18/2012||03/15/2013||117 days|
|Expedition 35||03/15/2013||05/13/2013||58 days|