What You Need to Know: High levels of vigorous exercise or brisk walking may be associated with a reduction in incidence of breast cancer in African American women.
Background: Physical activity has been associated with reduced risk of breast cancer. However, evidence on the association in African Americans has been limited.
The Study: Using prospective data from the Black Women’s Health Study, researchers assessed vigorous exercise and walking in relation to incidence of invasive breast cancer overall (n=1,364), estrogen receptor–positive (ER+, n=688) cancer, and estrogen receptor–negative (ER–, n=405) cancer, based on 307,672 person years of follow–up of 44,708 African American women aged 30 or older at enrollment.
Results: This prospective study found that high levels of vigorous exercise or brisk walking may be associated with a reduction in incidence of breast cancer in African American women.
- Vigorous exercise at baseline was inversely associated with overall breast cancer incidence (p trend=0.05): the IRR for ≥ 7 hour/week relative to < 1 hour/week was 0.74 (95% CI 0.57–0.96).
- The association did not differ by ER status.
- Brisk walking for ≥ 7 hours/week was associated with a reduction similar to that for vigorous exercise.
- Vigorous exercise at age 30, age 21, or in high school was not associated with breast cancer incidence.
Sitting for long periods at work or watching TV was not significantly associated with breast cancer incidence.
My Take: You can reduce your risk of breast cancer by about a quarter by simply walking briskly on a regular basis. Aim for an hour a day. Now, go do it! I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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Reference: Rosenberg et al. Cancer Epidemiology, Biomarkers & Prevention. Cancer Epidemiol Biomarkers Prev. 2014 Aug 7. [Epub ahead of print]