Research on exercise, weight and vitamin D offer insights for protection from osteoporosis.
BETHESDA, MD — Many breast cancer patients and survivors are unaware that they face increased risk of bone loss, which can lead to osteoporosis and increased risk of fractures and falls. Studies on vitamin D and exercise, both strength training and aerobic, revealed essential strategies survivors can take to minimize bone loss, according to research presented today at the American Institute for Cancer Research (AICR) Annual Research Conference.
“We know bone loss is a serious problem for breast cancer survivors,” said M. Tish Knobf, PhD, RN, Professor at the Yale School of Medicine. But both during and after treatment, “not every provider tells these women they are at increased risk of bone loss and this is the time survivors need to be aware…. If you can prevent or minimize how much bone is lost with exercise, that would be powerful.”
Treatments such as aromatase inhibitors (AIs) block the production of estrogen, a hormone needed for bone formation but one that fuels the growth of many breast cancers. Chemotherapy can induce early menopause, also leading to low estrogen levels and bone loss.
More than 40 million people living in the United States currently have osteoporosis or low bone mass, and more than three quarters of them are women.
Knobf reported the findings of a new 12-month study comparing two exercise regimens among breast cancer survivors who had recently completed therapy. Approximately half the women went to a fitness center three times a week for an aerobic/resistance exercise program. The other group was given national recommendations of 30 minutes of moderate intensity physical activity most days of the week.
Resistance exercise preserves bone mass for healthy post-menopausal women and it’s especially important within the first five years of menopause, when women have the greatest bump in the amount of bone they lose, says Knobf.
In one important finding, the women in the intervention group showed improved signs of heart and metabolic health compared to the home-based group. The intervention group had greater physical endurance, increased muscle mass and decreased fat mass.
“Our current study suggests that endocrine therapy after breast cancer influences bone loss and exercise may minimize the predicted rates of bone loss with adjuvant therapy.
“Women who are completing cancer therapy should be getting a strong prescription for health promotion, which includes aerobic-resistance exercise. Routine exercise improves muscle strength, balance, quality of life, mood, functional ability, cardiovascular status and may minimize the risk of bone loss,” said Knobf.
Vitamin D and Calcium
Cancer patients experience numerous complexities that suggests many will likely need supplements, said Bess Dawson-Hughes, MD, Senior Scientist and Director of the Bone Metabolism Laboratory at Tufts University.
Our bodies use vitamin D to absorb calcium, which is needed for bone formation. Most of our vitamin D comes from exposure to the sun, which is synthesized into the hormone. Diet also naturally provides vitamin D, although few foods contain it.
General risk factors for low vitamin D levels include obesity, spending little time in the sun and dark skin.
“Many cancer patients are at increased risk for low vitamin D levels and they should absolutely be checked for vitamin D.
“Patients with breast cancer and several other cancers are at increased risk of rapid bone loss and fractures. While not sufficient to prevent bone loss when taken alone, calcium and vitamin D are very important components of any pharmacologic regimen to minimize bone loss,” said Dawson-Hughes.
Other research on bone loss and cancer survivors presented at today’s session highlights:
- The role of calcium and vitamin D in bone health in the general population and women at increased risk, presented by Bess Dawson-Hughes, MD, Tufts University
- How exercise and planned weight loss influence bone health for breast cancer survivors, presented by Kathleen Y. Wolin, ScD, FACSM, Loyola University of Chicago
- Osteoporosis in cancer survivors: risk, prevention, and treatment options, presented by Ari VanderWalde, MD, MPH, MBioeth, Amgen Inc.