Exercise for the Chemo Brain

Chemotherapy can produce a broad range of negative consequences. Chemo brain is a common term used by cancer survivors to describe a series of cognitive impairments, including confusion, difficulty with learning new skills or multitasking, and feelings of mental fogginess. The condition may be a consequence of the cancer’s actions within the body or result from the therapies used to treat the cancer and its symptoms. Chemo brain occurs more often following administration of higher doses of chemotherapy and is also more likely to develop if the brain is exposed to radiation during the therapy. During the recovery phase after treatment, patients often have low blood counts that might reduce the availability of oxygen to the brain. Many patients also report significant sleep problems that are often associated with impaired daytime cognitive function, irritability, and memory loss. Widespread inflammation that directly and negatively affects brain function also contributes to the symptoms of chemo brain.

In addition, fatigue is a common symptom of chemo brain and may contribute significantly to the cognitive impairment. Fatigue is a common symptom of brain inflammation associated with other diseases. Thus, it is not surprising that increased levels of pro-inflammatory proteins have been reported in the blood of patients with chemo brain. The degree of fatigue is often correlated with the severity of depression; both of these are likely a consequence of increased serum levels of the cytokine interleukin-6. (If you would like to read more about the role of inflammation in chemo brain, see the reference below.)

Executive functions are often impaired as part of chemo brain. Executive functions are mental processes mostly happening in the cortex that control and regulate complex behaviors and actions. One of these executive functions, called working memory, that is lost is the ability to temporarily store, decipher, and apply newly acquired information. These many different symptoms explain why breast cancer survivors often report difficulties associated with returning to work, concentrating on new tasks, paying attention, multi-tasking, or fulfilling their regular roles in society. Fortunately, for most cancer survivors chemo brain tends to be mild and to dissipate over time. Does exercise help?

Exercise may mitigate the executive function and working memory problems associated with chemo brain. Physically active breast cancer survivors perform better on working memory, executive function, and attention tasks. Exercising is a well-known treatment for cancer-related fatigue possibly via its ability to protect against body and brain inflammation. One recent study concluded that the benefits of exercise on executive function and memory were due to the reduction in fatigue. Unfortunately, this study failed to examine for changes in inflammatory markers in the body and brain. However, their finding is consistent with the hypothesis that fatigue and the consequences of inflammation are the mechanisms linking cancer treatment and chemo brain. In spite of the recognized benefits of exercising, epidemiological evidence suggests that most breast cancer survivors participate in very little exercise each day.

Many survivors report that pain is a common problem, especially in the first few years after treatment, and that the pain makes it difficult to exercise regularly. These breast cancer survivors are not alone in terms of the need to deal with daily energy-sapping pain. Indeed, pain, either modest or severe, is the most common neurological condition experienced by everyone, almost daily.