Just ten minutes of exercise increases cancer-destroying cells and helps alleviate the side effects of treatment, according to a new study. Until now doctors believed patients should just rest after a cancer diagnosis, but light or moderate work-outs were found to improve patients’ prognoses and quality of life too.
To test the theory researchers from Finland’s University of Turku asked recently-diagnosed lymphoma and breast cancer patients to do a ten minute stint on a bicycle. The numbers of several immune cells were compared before and after, and discovered the number of cancer-destroying cells increased after the cycle.
After the work-out lymphoma patients had more cytotoxic T cells and natural killer cells, both of which attack cancer cells. Meanwhile the bloodstream of breast cancer patients contained more white blood cells, more intermediate monocytes and B cells that process antigens, as well as extra cytotoxic T cells and natural killer cells.
Changes were rapid and transient, most patients’ immune cell counts returned to normal 30 minutes after the exercise finished. Experts also discovered the harder participants pedalled the more the immune cells were transferred into the bloodstream.
Cancer treatments often weaken the immune system by reducing the number of immune cells, meaning exercise can play a vital role. Research Assistant Tiia Koivula, University of Turku, said: “It was previously thought that cancer patients should just rest after a cancer diagnosis.
“Today, we have more and more researched information that exercise can even improve the prognosis of cancer. However, it is not yet fully known how exercise controls cancer. The pedalling resistance was determined individually for each patient so that it corresponded to light or moderate physical activity. The most important goal was that the patients were able to pedal for 10 minutes straight without exhaustion, but so that their heart rate increased.
“It is especially interesting that we saw an increase in cytotoxic immune cells during the exercise in both patient groups. These immune cells are capable of destroying cancer cells. Although our results indicate that the higher the exercise intensity is, the more immune cells are transferred from their storage organs into the bloodstream, it is notable that also light or moderate intensity exercise lasting for only 10 minutes will cause an increase in the number of immune cells which are important for fighting cancer.
“Cancer treatments can make you tired and lower your motivation for exercise, which is why it is comforting to know that just ten minutes of cycling or walking to a supermarket, for example, can be enough to boost the body’s immune system. Further research in cancer patients is needed to study whether the immune cells are transported to the tumour after the exercise, where they could destroy cancer cells.
"This has been shown to happen in preclinical studies, but research in cancer patients is still rather incomplete.”
The scientists do not yet know where the immune cells enter the bloodstream from or where they go after the exercise. Previous studies found physical activity causes more immune cells to be transferred to the tumour site, where they become more active destroying cancer cells.
Unlike the earlier studies that focussed on patients who were not yet diagnosed, the University of Finland focussed their attention on patients. They picked 28 recently-diagnosed patients. The lymphoma patients were aged between 20 and 69, and breast cancer between 37 and 73.
Blood samples were taken once before the 10 minute cycle and twice after for the study published in the journal Scientific Reports.
