A new study led by researchers at Texas A&M University finds that a currently unspecified factor released during exercise suppresses signaling within breast cancer cells, which reduces tumor growth and can even kill the cancerous cells. The researchers also found that the factors inherently reside in muscle and are released into the bloodstream no matter what a person’s usual activity level is or how developed their muscles are.
To measure the level of factors released by exercised muscle, the researcher trained rats to complete a moderate-intensity exercise program. The rats ran on treadmills for five weeks and researchers gradually increased the incline. Although the research team could not identify an exact minimum muscle contraction time necessary for the effect, they did note that the longer the contraction session lasted, the more factors were released.
Amanda Davis, a clinical assistant professor at the Texas A&M School of Veterinary Medicine & Biomedical Sciences and the lead author of the paper, said that “these data are exciting because they show that during muscle contraction, the muscle is actually releasing some factors that kill, or at least decrease the growth of, neoplastic (abnormal, often cancerous) cells. Our results suggest that whether you consistently exercise or you just get up and walk when you’re not used to working out, these factors are still being released from the muscle. Even simple forms of muscle contraction, whether it be going on a walk or getting up to dance to your favorite song, may play a role in fighting breast cancer.”
Dr. Davis concluded that “the big message is to get up and move. You don’t have to be an Olympic-level athlete for these beneficial effects to occur during muscle contraction; being physically fit doesn’t make you more likely to release this substance.”
Dr. Davis holds a bachelor’s degree in biology and a Ph.D. in kinesiology from Texas A&M University.