Abstract
Our study investigates the effects of long-duration spaceflight on brain aging in spacefarers using structural MRI and machine learning models. Pre-, post-, and follow-up scans of ROS cosmonauts ESA astronauts, and matched Earth-bounding controls were analyzed. We found a considerable difference between the spacefareres and the control group, especially in the ESA cohorts (ß = 0.63). In the ROS cohorts, we observed a difference between the pre- and post-flight scans. A post-hoc analysis revealed that the pre-flight brain age delta was 0.842 years less than the immediate post-flight brain age delta after long-duration spaceflight. All three machine learning models showed good to excellent intraclass correlation coefficients (ICC) between the two consecutive MRI sessions. Our findings suggest that long-duration spaceflight may have an effect on human brain aging as observed from MRI.
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The code used for analysis in this manuscript will be made available. However, due to privacy and ethical restrictions, the data itself will not be shared.
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Acknowledgements
We thank all cosmonauts, astronauts, and volunteers for their participation. This work was supported by the Belgian Science Policy Prodex, European Space Agency (ESA) (ISLRA 2009-1062 to F.W.), Russian Academy of Sciences (FMFR-2024-0033), and the Research Foundation Flanders (FWO Vlaanderen to A.V.O.). This work was also supported by the German Aerospace Centre (DLR) on behalf of the Federal Ministry of Economics and Technology/Energy (50WB2027 to P.z.E.), the Deutsche Forschungsgemeinschaft (DFG, PA 3634/1-1 to K.P. and EI 816/21-1 to S.E.), and the Helmholtz Portfolio Theme “Supercomputing and Modelling for the Human Brain” (to K.P.).
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G.T. and P.z.E. conceptualised the study and led the manuscript writing. They, along with K.P., F.H., and S.M., conducted the data analysis. The remaining co-authors contributed to data collection, provided critical feedback, and helped shape the research.
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A.V.O. is an Associate Editor of npj Microgravity. The authors declare no other competing interests.
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Tang, G., Patil, K.R., Hoffstaedter, F. et al. Longitudinal brain-age predictions comprising long-duration spaceflight missions. npj Microgravity (2026). https://doi.org/10.1038/s41526-026-00575-3
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DOI: https://doi.org/10.1038/s41526-026-00575-3
