Effectiveness of nutritional countermeasures in microgravity and its ground-based analogues to ameliorate musculoskeletal and cardiopulmonary deconditioning–A Systematic Review

Abstract

A systematic review was performed to evaluate the effectiveness of nutrition as a standalone countermeasure to ameliorate the physiological adaptations of the musculoskeletal and cardiopulmonary systems associated with prolonged exposure to microgravity. A search strategy was developed to find all astronaut or human space flight bed rest simulation studies that compared individual nutritional countermeasures with non-intervention control groups. This systematic review followed the guidelines of the Cochrane Handbook for Systematic Reviews and tools created by the Aerospace Medicine Systematic Review Group for data extraction, quality assessment of studies and effect size. To ensure adequate reporting this systematic review followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analyses. A structured search was performed to screen for relevant articles. The initial search yielded 4031 studies of which 10 studies were eligible for final inclusion. Overall, the effect of nutritional countermeasure interventions on the investigated outcomes revealed that only one outcome was in favor of the intervention group, whereas six outcomes were in favor of the control group, and 43 outcomes showed no meaningful effect of nutritional countermeasure interventions at all. The main findings of this study were: (1) the heterogeneity of reported outcomes across studies, (2) the inconsistency of the methodology of the included studies (3) an absence of meaningful effects of standalone nutritional countermeasure interventions on musculoskeletal and cardiovascular outcomes, with a tendency towards detrimental effects on specific muscle outcomes associated with power in the lower extremities. This systematic review highlights the limited amount of studies investigating the effect of nutrition as a standalone countermeasure on operationally relevant outcome parameters. Therefore, based on the data available from the included studies in this systematic review, it cannot be expected that nutrition alone will be

Learning From Human Responses to Deconditioning Environments: Improved Understanding of the “Use It or Lose It” Principle

“…Bedrest differs from space flight in that in space, the gravity variable is removed, but in bedrest the 1 g variable is still present but the individual no longer works against it. However, there can be rapid muscle and bone loss, with the bone loss quite variable, similar to what has been observed in space (Kos et al, 2013 ), and cardiovascular deconditioning as well (Fortrat et al, 2001 ; Orter et al, 2020 ; Sandal et al, 2020 ; Solbiati et al, 2020 ), which again mimics the observations from space. In addition, chronic bedrest can lead to impairment of neuro-functions related to memory, and these can be reversed by exercise (Friedl-Werner et al, 2020 ).…”

Developing, Implementing, and Applying Novel Techniques During Systematic Reviews of Primary Space Medicine Data

“…One review 13 used qualitative methods to present a thematic analysis of technical documents from grey literature sources required to answer the technical nature of the research question. Three reviews 25,31,32 included bed rest spaceflight simulation studies and reported bed rest quality scores. One review 24 used the quality of partial gravity simulations to list how well various ground simulations are likely to accurately model astronaut biomechanical, cardiovascular and metabolic changes.…”

Effects of exercise countermeasures on multisystem function in long duration spaceflight astronauts

“…Recapitulation of ground-based loading cycles of daily activities during 84 days of bed rest attenuated, but did not eliminate, the decline in several musculoskeletal and cardiovascular health parameters 23 . Nevertheless, findings from systematic reviews indicate that nutritional countermeasures could ameliorate musculoskeletal and cardiopulmonary deconditioning 24 , while findings from bed rest studies indicate that including plyometric exercise (hopping and whole body vibration) may be adjunct options to mitigate musculoskeletal loss on exploration missions where resources are limited 25 . Finally, lower body negative pressure (LBNP) coupled with exercise could offset the spaceflight-induced headward shift in vascular and cerebrospinal fluid and mitigate declines in cardiorespiratory fitness 26 .…”