Written by Jessica Patella, ND. Studies show that consumption of flaxseed or flax bread was associated with a 20 – 30% reduced risk of developing breast cancer.
An estimated 1 in 8 women in the United States will develop breast cancer in her lifetime, making it the second most common cancer among women (2). The National Cancer Institute estimates breast cancer costs an average of $16.5 billion dollars per year, making breast cancer both a public health and economic concern (3). Recent research has shown that consuming flaxseed reduces the risk of breast cancer (1).
Recent studies found high consumption of lignans, a type of chemical found in plants, was associated with a reduced risk of breast cancer after menopause (4,5). Flaxseeds are the richest source of lignans, but studies had not reviewed flaxseed’s effect on breast cancer independently, until now (1).
The first study to review flaxseed consumption on breast cancer included 2,999 women with a diagnosis of breast cancer and 3,370 women without a diagnosis of breast cancer, all 25-74 years old (1). Each woman completed a food frequency questionnaire with 178 food items, including flaxseed or flax breads (intake of flaxseed oil was not included because it does not contain lignans) (1).
After review, consumption of flaxseed and flax bread was associated with a 20-30% reduced risk of breast cancer (OR=0.82, 95%CI 0.69-0.97).
Flaxseed alone was associated with a reduced risk of breast cancer in postmenopausal women only who consumed flaxseed daily or weekly (OR=0.73, 95%CI 0.60-0.89; 1 serving= 1/4 cup flaxseed). Consuming flax bread was associated with a reduced risk of breast cancer in both pre and postmenopausal women who consumed flaxseed daily or weekly (OR=0.74, 95%CI 0.62-0.88; 1 serving = 1 slice flax bread) (1).
Previous studies have shown that greater than 5.4 mg of lignan consumption was associated with a reduced risk of breast cancer (6). One teaspoon of flaxseed contains more than 13 mg of lignans, giving an idea of how little is needed to possibly have a positive impact on health (1,6).
In conclusion, consuming flaxseed or flax bread was associated with a 20-30% reduction in the risk of breast cancer. This was the first study to address the association between eating flax and the risk of breast cancer. Future research to determine the optimal amount of flaxseed or flax bread consumption should be considered (1).
Source: Lowcock, Elizabeth C., Michelle Cotterchio, and Beatrice A. Boucher. “Consumption of flaxseed, a rich source of lignans, is associated with reduced breast cancer risk.” Cancer Causes & Control 24.4 (2013): 813-816.
© Springer Science+Business Media Dordrecht 2013
Posted May 13, 2013.
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health. She earned her ND from Southwest College of Naturopathic Medicine in Tempe, AZ, and is a member of the North Carolina Association of Naturopathic Physicians. Visit her website at www.awarenesswellness.com.
References:
- Lowcock E, et al. Consumption of flaxseed, a rich source of lignans in associated with reduced breast cancer risk. 2013 Cancer Causes Control 24: 813-816.
- US Breast Cancer Statistics. See Breast Cancer.org
- The Cost of Cancer. National Cancer Institute.
- Buck K, et al. Meta-analyses of lignans and enterolignans in relation to breast cancer risk. 2010 Am J Clin Nutr 92:141–153
- Velentzis LS, et al. Lignans and breast cancer risk in pre- and post-menopausal women: meta-analyses of observational studies. 2009 Br J Cancer 100:1492–1498
- Cotterchio M, et al. Dietary phytoestrogen intake–lignans and isoflavones–and breast cancer risk (Canada). 2008 Cancer Causes Control 19:259–272.
