ST. LOUIS, Mo. — Chemotherapy is one of the most effective tools modern medicine has to fight against cancer, but a major side-effect of the treatment is an increase in cognitive impairments — or “chemobrain.” However, a recent observational study finds moderate to vigorous exercise can lower the risk of developing “chemobrain” in women with early-stage breast cancer.
“Cognitive decline related to cancer treatment is a growing clinical concern,” says Elizabeth Salerno, PhD, an assistant professor of surgery at the Washington University School of Medicine in St. Louis, in a media release. “Some patients with cancer experience memory lapses, difficulty concentrating or trouble finding the right word to finish a sentence. Knowing the detrimental effects of chemotherapy on cognitive function, we wanted to understand the dynamic relationships between physical activity and cognition before, during and after chemotherapy to hopefully inform early, cost-effective prevention strategies to promote health in these patients.”
Using a questionnaire, the researchers measured the physical activity levels of 580 patients with breast cancer before and after chemotherapy. The average age of patients with stage I to IIIC breast cancer was 53. They also collected physical activity levels from 363 people without cancer who served as the control group.
150 minutes a week may save the brain
About 33 percent of patients with cancer were engaging in 150 minutes of moderate to vigorous physical activity per week — sticking to guidelines set by the U.S. Department of Health and Human Services. During chemotherapy, only 21 percent of people were meeting physical activity guidelines.
More patients began exercising after chemotherapy. The initial 21 percent performing moderate to vigorous exercise jumped to 37 percent six months after chemotherapy.
The researchers measured women’s brain health through two self-evaluations of people’s cognitive performance, a visual memory test, and a sustained attention test.
Results show that patients who did not exercise at all had significant decreases in cognitive function. Meanwhile, patients who participated in high levels of physical activity before and after chemotherapy maintained high cognitive function throughout treatment.
Exercising before chemotherapy but not during or after still had some cognitive benefits in terms of memory and attention. If there were declines in cognition during chemotherapy, the declines were not as severe as patients who are physically inactive.
“By assessment with our objective cognitive measures, patients who were meeting physical activity guidelines prior to chemotherapy had better cognitive function scores following chemotherapy and looked cognitively similar to people who didn’t have cancer,” says senior author Michelle Janelsins, PhD, an assistant professor at the University of Rochester Medical Center and Wilmot Cancer Institute.
The study is published in the Journal of Clinical Oncology.