For Men with Prostate Cancer
Can Exercise Buffer the Cognitive Effects of Hormone Therapy?
by Allison Hourani, BA, Tatiana D. Starr, MA, and Christian J. Nelson, PhD
Androgen deprivation therapy, or hormone therapy, is a mainstay of treatment for many men with prostate cancer. For those with advanced disease, it is the standard of care. Androgen deprivation therapy works by depleting a man’s testosterone, which is a major driver in the growth of prostate cancer cells.
However, while hormone therapy is effective in managing the disease, this type of treatment often comes with some unpleasant side effects. These can include hot flashes, osteoporosis, anemia, fatigue, muscle loss, swelling of the
breast tissue, loss of libido, erectile dysfunction, and increased risk of diabetes, cardiovascular disease, and fatal cardiac events, not to mention emotional distress.
Additionally, recent studies have suggested that androgen deprivation therapy can impair cognitive function. Since testosterone is found in areas of the brain responsible for learning and memory, the reduction of testosterone from hormone therapy may directly affect these areas. The areas most often affected are visuospatial abilities, working memory, executive functioning, verbal memory, and processing speed. Cognitive functioning may also be indirectly affected by the other side effects of androgen deprivation therapy.
As evidence of hormone therapy’s negative impact on cognitive functioning continues to grow, investigators are exploring ways to mitigate these effects. One of the more promising interventions is exercise.
In adults with mild cognitive impairment, exercise has been shown to improve attention, processing speed, executive function, memory, and working memory. Since many of these exercise studies include samples of older men (in whom testosterone levels are generally depressed), there are promising indications that exercise may also be effective for men receiving hormone therapy.
Researchers believe there are three potential mechanisms for which exercise may influence brain function:
- Aerobic exercise may increase blood flow to and from the heart and the brain.
- Exercise may have an effect on neurotransmitters, or brain chemicals, responsible for concentration and alertness.
- Exercise can increase a specific type of chemical in the brain called brain-derived neurotrophic factor. BDNF helps the brain generate new neurons, particularly in the areas of the brain related to learning, memory, and higher-level thinking.
Exercise does not need to be vigorous in order to be beneficial. The exercise reported in these studies was moderate, generally brisk walking or jogging.
The take-home message for men with prostate cancer is that thirty minutes of moderate physical activity a few days each week should be enough to potentially counteract the cognitive effects of androgen deprivation therapy. This can include walking, jogging, or even performing common household chores like gardening or raking leaves.
You can even make some small lifestyle changes to ramp up the physical activity in your daily routines, for example taking the stairs instead of the elevator, or parking your car at the far end of the lot.
While investigators have yet to prove conclusively that exercise alone can buffer the cognitive effects of androgen deprivation therapy, the current research certainly is promising. Besides, numerous other health benefits of exercise are well established. For your health – both mental and physical – talk with your doctor about incorporating physical activity and exercise into your survivorship care plan.
Previously a research study assistant at Memorial Sloan Kettering Cancer Center in New York, NY, working on quality-of-life and cognition research in men with prostate cancer, Allison Hourani (not pictured) is now studying social work at the Silver School of Social Work at New York University. Tatiana Starr is a clinical research supervisor at Memorial Sloan Kettering, where she has helped manage a number of quality-of-life research studies in men with prostate cancer. Dr. Christian Nelson is a clinical psychologist with expertise in treating men with prostate cancer and other genitourinary diseases at Memorial Sloan Kettering.
This article was published in Coping® with Cancer magazine, January/February 2016.