Food and Health

Cancer Prevention Properties of Flaxseed

I have a high risk for breast cancer.  My maternal grandmother, mother, maternal aunt, and only sister all have had breast cancer between the ages of 48 and 53.  I went to a genetic counselor when I was in my late 40s and was told my absolute risk of breast cancer is nearly 70%.

That doesn’t mean my risk of breast cancer is increase by 70%.  It means I have a 70% absolute risk of getting breast cancer according to the genetics counselor.  We tested negative for the BRCA gene, but the genetic counselor informed me that there are many other genetic dispositions I could potentially have, they just haven’t been properly identified.

Ironically, I was diagnosed with gastroesophageal reflux disorder (GERD) in 2010 at age 43.  Shortly after starting my prerequisites for my graduate nutrition studies in 2014 I decided to stop taking my omeprazole, a proton pump inhibitor (PPI).  I learned that these drugs can cause serious nutrient deficiencies when taken long term, and I had already been taking one every single day for nearly 4 years.

I had done some research to find an alternative solution to GERD and read that in some countries they used whole flaxseed to treat GERD.  I started swallowing a teaspoon of whole flaxseed with a glass of water every morning on an empty stomach and every evening before I went to bed.  While there is no strong scientific evidence behind this remedy, it worked for me.

Flaxseed and Breast Cancer

I later learned in my nutrition studies that flaxseeds have cancer prevention properties specifically for estrogen-dependent breast cancer.  When whole or ground flaxseeds are eaten, the gut microbiome interacts with these seeds to form mammalian lignans.1  Indeed, a clinical trial administering 25g of ground flaxseed to estrogen-dependent, post-menopausal breast cancer patients showed a reduction in tumor growth and an increase in cancer cell death among those eating the flaxseed compared with a placebo group (a group not eating flaxseed, but a similar dietary product that could not be distinguished from the flaxseed product).1  In fact, several studies have indicated that because of the chemical properties of  flaxseeds, they may be a potential replacement for breast cancer drug treatments like tamoxifen, or potentially used for prevention of certain breast cancer types.1

Another study showed that not only ground flaxseed, but also whole flaxseed also produced the same mammalian lignans as ground flaxseed.2  This study compared the lignan producing properties of both flaxseed and sesame seed and found sesame seed also to be effective in producing the cancer protective lignans.2

While my personal experience certainly cannot be classified as a “scientific study”, I can tell you that each year at the time of my screening (sometimes I’m screened twice per year with a breast MRI following 6 months after my mammogram) I am relieved to find the results are negative.  Currently I incorporate both whole and ground flaxseed into my diet, and I can never know for certain if eating flaxseeds every day for so long has helped keep the breast cancer beast away in my case.  More than likely it may be a combination of eating flaxseed and the multitude of other dietary changes I made during my studies.  However, I have a 70% risk of breast cancer, have all maternal family members diagnosed between the ages of 48 and 53, and I am currently 51 years old and breast cancer free.


  1. Thompson LU, Chen JM, Li T, Strasser-Weippl K, Goss PE. Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer.  Clinical Cancer Research. 2005; 11(10):  3828 – 3835.
  2. Coulman KD, Liu Z, Hum WQ, Michaelides J, Thompson LU. Whole sesame seed is as rich a source of mammalian lignan precursors as whole flaxseed. Nutrition and Cancer. 2005; 52(2): 156-165.

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About Laura Cadoret, MS

Helping people see the big picture in food industry and nutrition
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