Flax Seed and Breast Cancer
There are so many articles and suggestions about what we should or should not eat. Most of them have no real scientific backing, but some do--and those tend to be inconclusive and uncertain. Here is an editorial from the Journal of Clinical Oncology that fits that description. The question at hand is whether the inclusion of half a cup of flax seed daily reduces the recurrence risk of breast cancer. If you click the link and read the entire article, you will find the conclusion that not enough is known to make a recommendation.
As an aside, I am now even more baffled by who bought and left the bag of flax seed in the freezer of our cottage in Maine. Various family members and friends used it over the summer, and it was always fun to arrive after them and find some left over treats. Usually those unexpected goodies were along the lines of a bottle of wine, ice cream, cheese, or marinated something. However, once there was a bag of flaxseed and no number of inquiries resulted in anyone's claiming it.
Here is the beginning and a link:
Flaxseed and Breast Cancer: What Should We Tell Our Patients?
Ruth E. Patterson, Moores Cancer Center, University of California, San Diego, La Jolla, CA
In the United States alone, there are approximately 2.6 million survivors of breast cancer.1 This population is highly motivated to initiate lifestyle changes in diet and exercise to improve their prognosis.2
Dietary lignans have been identified as potentially protective against breast cancer via estrogen-dependent and independent anti- carcinogenic activity.3 Lignans are bioactive, non-nutrient, noncaloric phenolic plant compounds that are found in large amounts in flax- seeds and sesame seeds and in small amounts in whole grains, le- gumes, and certain fruits and vegetables (Table 1).3 For example, one half cup of whole wheat meal is estimated to provide approximately 325 ??g lignans, whereas one half cup of flaxseed provides approxi- mately 275,000 ??g lignans. In humans, lignans are metabolized by the gut microflora into enterolignans; enterolactone is the main metabo- lite.4 Therefore, enterolactone concentrations in serum, plasma, and urine have been used as biomarkers of dietary lignans.
The article by Buck et al5 that accompanies this editorial investi- gates the association of enterolactone with breast cancer outcomes. Specifically, the authors found that among 1,140 patients with breast cancer who were postmenopausal, serum enterolactone concentra- tions in the highest quartile were associated with an approximate 40% reduced risk of overall mortality (hazard ratio, 0.58; 95% CI, 0.34 to 0.99) and distant disease (hazard ratio, 0.62; 95% CI, 0.35 to 1.09). Although this is the first such study in survivors of breast cancer, these findings are supported by a recent meta-analysis that indicates that enterolactone biomarkers are associated with a statistically significant 28% reduced risk of incident breast cancer.6