Researchers at the University of Copenhagen gave mice access to a running wheel across five tumor models, from implanted to chemically induced and inherited, then compared tumor growth against mice with no wheel to run on.
Mice that voluntarily ran saw tumor incidence and growth fall by more than 60 percent across all five tumor models tested. Natural killer immune cells flooded into the tumors of running mice far more than in sedentary mice, and when the researchers depleted those cells, most of the protection from running was lost.
The team traced the mechanism to adrenaline released during exercise, which mobilized natural killer cells into the bloodstream, and to the muscle-released signal interleukin-6, which helped direct those cells specifically into the tumors rather than just circulating uselessly. Blocking either adrenaline signaling or interleukin-6 independently blunted the tumor-suppressing effect of running, confirming both steps were required rather than exercise working through some unrelated pathway.
Read the original study
Pedersen et al., Cell Metabolism, 2016 · doi.org/10.1016/j.cmet.2016.01.011
Running sent killer cells straight to the enemy.
Source
- Pedersen, L., Idorn, M., Olofsson, G. H., Lauenborg, B., Nookaew, I., Hansen, R. H., Johannesen, H. H., Becker, J. C., Pedersen, K. S., Dethlefsen, C., Nielsen, J., Gehl, J., Pedersen, B. K., Thor Straten, P., & Hojman, P. (2016). Voluntary Running Suppresses Tumor Growth through Epinephrine- and IL-6-Dependent NK Cell Mobilization and Redistribution. Cell Metabolism, 23(3), 554–62. https://doi.org/10.1016/j.cmet.2016.01.011