A new Finnish study from University of Turku shows that already a 30-minute exercise can increase the proportion of tumor-killing white blood cells in the bloodstream of breast cancer patients. White blood cells, the cells of our immune system, fight against cancer, bacteria, and viruses. However, not all white blood cells destroy cancer cells and some can even promote cancer growth.
The most important cell types that destroy cancer cells are cytotoxic T cells and natural killer cells. Cell types that support cancer growth include, for example, regulatory T cells and myeloid derived suppressor cells. The balance of different types of white blood cells determines whether the immune system works to destroy cancer or to support it.
If there are more cancer-destroying cells than cancer-promoting cells in the tumor area, the body is more capable of fighting cancer." Tiia Koivula, Lead Author, Doctoral Researcher, University of Turku, Finland Twenty breast cancer patients who had just been diagnosed and therefore had not yet started their cancer treatments participated in the study. During the study, the patients pedaled a bicycle ergometer for 30 minutes at a resistance of their own choosing.
Blood samples were taken from the patients at rest before the pedaling, during the exercise, and after the exercise. Blood samples were analysed to calculate the amount of many different types of white blood cells, and the amounts measured during the exercise were compared to those at rest. D.