Study Links High Soy Diet to Osteoporotic Fractures in Breast Cancer Survivors

Introduction to Breast Cancer and Osteoporosis Risk

A recent study explored the relationship between a high soy diet and the occurrence of osteoporotic fractures among women who have successfully undergone treatment for breast cancer. Breast cancer remains the most prevalent cancer after skin cancer among women in North America and is the second-leading cause of cancer-related deaths in this demographic. Hormone receptor-positive breast cancer, commonly referred to as ER-positive breast cancer, is the most frequently diagnosed type.

Impact of Breast Cancer Treatment on Bone Health

Breast cancer treatments can lead to a decrease in bone mineral density, resulting in a heightened risk of osteoporosis-related fractures for survivors compared to their healthy counterparts of the same age. While strategies such as calcium and vitamin D-rich diets, regular exercise, and smoking cessation can mitigate osteoporosis risk, the effect of a high soy diet remains uncertain.

The Role of Isoflavones in Soy Products

Soy-based products are rich in isoflavones, a group of phytoestrogens that mimic estrogen and influence its metabolism. The recent study published in JNCI Cancer Spectrum examined the connection between a high soy diet and the risk of osteoporotic fractures in breast cancer survivors.

Study Overview and Methodology

The research utilized data from the Shanghai Breast Cancer Survival Study (SBCSS), involving 3,986 patients aged 20 to 75 who were newly diagnosed with breast cancer. Among the participants, postmenopausal women constituted 52%, slightly higher than pre-/perimenopausal women. Researchers collected comprehensive information regarding cancer diagnosis, treatment, body mass index (BMI), dietary habits, exercise, and other lifestyle factors from medical records. All participants underwent in-person follow-ups at 18 months, as well as 3, 5, and 10 years post-diagnosis to assess their ongoing health status.

Findings on Osteoporotic Fractures

Throughout the ten-year period following their breast cancer diagnosis, survivors experienced 2.5 times more osteoporotic fractures compared to healthy women. Notably, a high soy diet was linked to a 77% reduction in osteoporotic fractures, particularly among younger participants. In contrast, no significant changes were observed in postmenopausal women, suggesting that high soy intake prior to menopause may be beneficial in preventing such fractures.

Effects of Tamoxifen on Fracture Risk

Among all age groups in the study, the medication tamoxifen—commonly used in breast cancer treatment—was associated with a 37% decrease in the risk of osteoporotic fractures among survivors, especially with prolonged use. Interestingly, tamoxifen exhibits a biological effect similar to that of a high soy diet, helping to reduce fracture risk regardless of menopausal status.

Implications for Future Research

Researchers express hope that these findings will contribute to the development of comprehensive strategies aimed at reducing fracture risk among women who have survived breast cancer.

Author Information

Written by Anna Otvodenko

Related Topics of Interest

– Can We Predict the Risk of Fractures in Women with Postmenopausal Osteoporosis?
– Top Drug-Based Osteoporosis Treatment Options
– Treating Osteoporosis in Men
– Osteoporotic Fracture and Bisphosphonates: What are the Long-Term Risks?
– Exploring the Impact of Carotenoids on Osteoporotic Fractures
– Stopping Osteoporosis Treatment May Increase the Risk of Vertebral Fracture
– Do High Blood Glucose Levels Increase Your Risk of Osteoporotic Fracture?
– Does a High Soy Diet Influence Osteoporotic Fracture in Breast Cancer Survivors?
– Monitoring and Improving Bone Mineral Density When You Have Osteoporosis

References

Zheng, N., Hsieh, E., Cai, H., Shi, L., Gu, K., Zheng, Y., Bao, P., & Shu, X. (2019). Soy Food Consumption, Exercise, and Body Mass Index and Osteoporotic Fracture Risk Among Breast Cancer Survivors: The Shanghai Breast Cancer Survival Study. JNCI Cancer Spectrum, 3(2).
Breast Cancer Statistics – Canadian Cancer Society. (2019) [online] Available at: https://www.cancer.ca/en/cancer-information/cancer-type/breast/statistics/?region=on [Accessed 28 May 2019].
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