Cited by 1,128Spaceflight effects on biologySpace exploration and regulationEffects of Radiation Exposure

The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight

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Garrett-Bakelman, Francine E., Darshi, Manjula, Green, Stefan J., Gur, Ruben C., Lin, Ling, Macias, Brandon R., McKenna, Miles J., Meydan, Cem +74 more·2019·Science

Abstract

What to expect after a year in space: Space is the final frontier for understanding how extreme environments affect human physiology. Following twin astronauts, one of which spent a year-long mission on the International Space Station, Garrett-Bakelman et al. examined molecular and physiological traits that may be affected by time in space (see the Perspective by Löbrich and Jeggo). Sequencing the components of whole blood revealed that the length of telomeres, which is important to maintain in dividing cells and may be related to human aging, changed substantially during space flight and again upon return to Earth. Coupled with changes in DNA methylation in immune cells and cardiovascular and cognitive effects, this study provides a basis to assess the hazards of long-term space habitation. Science , this issue p. eaau8650 ; see also p. 127

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Crossref · 10.1126/science.aau8650

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  • Astronauts exposed to radiation, high G-forces, zero gravity, and cabin air quality show an accelerated aging-like phenotype.

    “An accelerated aging-like phenotype has been observed in astronauts who are exposed to radiation, high G-forces, zero gravity and cabin air quality126.”

    From Cellular senescence and senolytics: the path to the clinic (2022) · cites this paper as [126]

    The Discussion section on persistent telomere loss reports postflight telomere shortening and identifies telomere length as a biomarker of aging. The paper also discusses physiological changes associated with weightlessness and radiation exposure, but it does not establish an overall accelerated aging-like phenotype in astronauts or link one to high G-forces or cabin air quality. Its year-long flight findings are principally from one astronaut. (LLM, conf=0.84)

    Experimental — accuracy not yet measured
  • Mitochondrial debris were observed in blood in the Twin Study, and mitochondrial DAMPs activate innate immune pathways.

    “Mitochondrial debris were observed in blood in the Twin Study (Garrett-Bakelman et al., 2019) and mitochondrial damage-associated molecular patterns (DAMPs) activate innate immune pathways (Banoth and Cassel, 2018; Zhang et al., 2010).”

    From Comprehensive Multi-omics Analysis Reveals Mitochondrial Stress as a Central Biological Hub for Spaceflight Impact (2020) · cites this paper as Garrett-Bakelman et al., 2019

    In Results, “Mitochondria-related adaptations during spaceflight” (page unavailable), the study reports mitochondrial DNA measured in blood plasma and increased mitochondrial RNA during flight. It does not identify the material in blood as mitochondrial debris. The DAMPs clause is attributed to other citations, not this paper. (LLM, conf=0.82)

    Experimental — accuracy not yet measured
  • After arriving back to Earth, the space-bound twin had considerably shortened telomeres compared to his brother, an important biomarker in biological aging and associated age-related diseases.

    “This study reported that, after arriving back to Earth, the space-bound twin had considerably shortened telomeres compared to his brother, an important biomarker in biological aging and associated age-related diseases.”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [5]

    The Results section reports that the space-bound twin’s telomeres shortened rapidly after his return to Earth, then stabilized near preflight averages; his brother’s telomere lengths remained relatively stable. It does not report that the returning twin’s telomeres were considerably shorter than his brother’s. The Discussion identifies telomere length as a biomarker of aging linked to age-related diseases. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Neuro-ocular syndrome occurs in approximately 40% of astronauts due to brain fluid displacement and associated adaptations to the hostile environment.

    “We must also remedy other neurological damages caused by spaceflight such as neuro-ocular syndrome, which occurs in approximately 40% of astronauts due to brain fluid displacement and associated adaptations to the hostile environment5.”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [5]

    The Discussion section on spaceflight-associated neuro-ocular syndrome (page not provided) says about 40% of astronauts had experienced one or more associated ocular issues as of May 2017. It identifies headward fluid shift and associated adaptations as a proposed explanation, not an established cause; the paper also says the exact mechanism is not well understood. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • In the NASA twins study, most of the analysis was performed on Earth with preserved samples taken from one of the twins; this is a recurrent practice that allows understanding any particular inflight risks; however, it limits the capacity of response on site.

    “In the NASA twins study, most of the analysis was performed on Earth with preserved samples taken from one of the twins; this is a recurrent practice that allow to understand any particular inflight risks; however, it limits the capacity of response on site5,119.”

    From Key points for the development of antioxidant cocktails to prevent cellular stress and damage caused by reactive oxygen species (ROS) during manned space missions (2021) · cites this paper as [5]

    Split into 2 atoms — 0 confirmed, 2 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.

    Experimental — accuracy not yet measured

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Research works printed but not linked: 1

  1. [12]Hayes JC, Guilliams ME, Lee SMC, MacNeill KR, Jr ADM, “ Exercise: developing countermeasure systems for optimizing astronaut performance in space” in Biomedical Results of the Space Shuttle Program, Risin D, Stepaniak PC, Eds. (NASA/SP-2013-607, NASA, Washington, DC, 2013), pp. 289– 314.

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Authors
Garrett-Bakelman, F. E., Darshi, M., Green, S. J., Gur, R. C., Lin, L., Macias, B. R., McKenna, M. J., Meydan, C., Mishra, T., Nasrini, J., Piening, B. D., Rizzardi, L. F., Sharma, K., Siamwala, J. H., Taylor, L., Vitaterna, M. H., Afkarian, M., Afshinnekoo, E., Ahadi, S., Ambati, A., Arya, M., Bezdan, D., Callahan, C. M., Chen, S., Choi, A. M. K., Chlipala, G. E., Contrepois, K., Covington, M., Crucian, B. E., De Vivo, I., Dinges, D. F., Ebert, D. J., Feinberg, J. I., Gandara, J. A., George, K. A., Goutsias, J., Grills, G. S., Hargens, A. R., Heer, M., Hillary, R. P., Hoofnagle, A. N., Hook, V. Y. H., Jenkinson, G., Jiang, P., Keshavarzian, A., Laurie, S. S., Lee-McMullen, B., Lumpkins, S. B., MacKay, M., Maienschein-Cline, M. G., Melnick, A. M., Moore, T. M., Nakahira, K., Patel, H. H., Pietrzyk, R., Rao, V., Saito, R., Salins, D. N., Schilling, J. M., Sears, D. D., Sheridan, C. K., Stenger, M. B., Tryggvadottir, R., Urban, A. E., Vaisar, T., Van Espen, B., Zhang, J., Ziegler, M. G., Zwart, S. R., Charles, J. B., Kundrot, C. E., Scott, G. B. I., Bailey, S. M., Basner, M., Feinberg, A. P., Lee, S. M. C., Mason, C. E., Mignot, E., Rana, B. K., Smith, S. M., Snyder, M. P., & Turek, F. W.
Affiliations
  • Weill Cornell Medicine (US)
  • The University of Texas at San Antonio Health Science Center (US)
  • University of Illinois Chicago (US)
  • University of Pennsylvania (US)
  • Stanford Medicine (US)
  • Wyle (United States) (US)
  • Colorado State University (US)
  • Johns Hopkins University (US)
  • University of California San Diego (US)
  • Northwestern University (US)
  • University of California, Davis (US)
  • National Aeronautics and Space Administration (US)
  • Harvard T.H. Chan School of Public Health, Boston, MA, USA.
  • University of Bonn (DE)
  • University of Washington (US)
  • Rush University Medical Center (US)
  • Stanford University School of Medicine, Palo Alto, CA, USA.
  • MEI Technologies (United States) (US)
  • University of Illinois at Chicago, Chicago, IL, USA.
  • Johns Hopkins University, Baltimore, MD, USA.
  • University of Washington, Seattle, WA, USA.
  • University of California, San Diego, La Jolla, CA, USA.
  • The University of Texas Medical Branch at Galveston (US)
  • National Space Biomedical Research Institute (US)
Corresponding author
  • Garrett-Bakelman, Francine E.
  • Darshi, Manjula
  • Green, Stefan J.
  • Gur, Ruben C.
  • Lin, Ling
  • Macias, Brandon R.
  • McKenna, Miles J.
  • Meydan, Cem
  • Mishra, Tejaswini
  • Nasrini, Jad
  • Piening, Brian D.
  • Rizzardi, Lindsay F.
  • Sharma, Kumar
  • Siamwala, Jamila H.
  • Taylor, Lynn
  • Vitaterna, Martha Hotz
  • Charles, John B.
  • Kundrot, Craig E.
  • Scott, Graham B. I.
  • Bailey, Susan M.
  • Basner, Mathias
  • Feinberg, Andrew P.
  • Lee, Stuart M. C.
  • Mason, Christopher E.
  • Mignot, Emmanuel
  • Rana, Brinda K.
  • Smith, Scott M.
  • Snyder, Michael P.
  • Turek, Fred W.
Venue
Science
Published
2019-04-12
Volume
364
Issue
6436
ISSN
  • 0036-8075 (ISSN-L)
  • 1095-9203
OpenAlex
W2939018266
Cited by
1,128
References
150
Citations by year
2026: 127 · 2025: 187 · 2024: 186 · 2023: 156 · 2022: 142 · 2021: 144 · 2020: 113 · 2019: 69
FWCI
80.21
Type
journal article
Language
en
Open access
Locations
  • Science (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • eScholarship (California Digital Library) (submittedVersion)
Funders
  • National Science Foundation (CCF-1656201)
  • National Institutes of Health (AG035031, 1R01MH117406, R21AO129851)
  • National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK104706, P30 DK035816, P30 DK017047)
  • National Aeronautics and Space Administration (NNX14AH51G, NNX14AB02G, NNX14AH27G, NCC 9-58, NN13AJ12G, NNX14AN75G, NNX17AB26G, NNX14AH52G, NNX14AH26G, NNX14AH50G, NNX16AO69A:0061, NNX16AO69A:0107)
  • DLR Space program (50WB1535)
  • WorldQuant Foundation
  • Starr Foundation (I9-A9-071)
  • Pershing Square Foundation (PSSCRA)
  • NASA Astrobiology Institute (NN13AJ12G)
  • NIDDK (DP3DK094352)
Topics
  • Health Sciences › Medicine › Physiology › Spaceflight effects on biology
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Space exploration and regulation
  • Health Sciences › Medicine › Radiology, Nuclear Medicine and Imaging › Effects of Radiation Exposure
Keywords
long-duration spaceflight, International Space Station, astronaut health, telomere length, genomic instability, DNA methylation, oxidative stress, gut microbiota, carotid artery, intima-media thickness, eye changes, gene expression, cognitive decline, post-flight recovery, spaceflight health risks
MeSH terms
Gastrointestinal Microbiome, Adaptation, Physiological, Body Weight, Carotid Arteries, DNA Damage, Humans, Male, Space Flight, Time Factors, United States, Astronauts, United States National Aeronautics and Space Administration, DNA Methylation, Genomic Instability, Adaptive Immunity, Carotid Intima-Media Thickness, Telomere Homeostasis

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