Is Flax Safe for Breast Cancer Survivors? A Reader Inspired Question!

English: Brown Flax Seeds. (Photo credit: Wikipedia)

I often get great questions from either my in person seminars or via email. These questions are things that I’m sure my readers are interested in as well, so I am planning to share the periodically with you.

This one came through email and is a common question I get from breast cancer survivors and anyone else with hormone positive cancer.

Q: I was diagnosed with breast cancer 2 years ago. My question is about flax seeds. My cancer was very early stage, but strongly hormone receptor-positive. I have heard that flax seeds and flax oil should be avoided for women with hormone-receptor positive cancer. Is this true? I am grateful for any help you can offer.

A: Great question! The short answer is that flax is perfectly safe. I would suggest the ground seeds (grind yourself or buy it ground) rather than the oil. There is a lot of good lignins in the seeds that you don’t get in the oil. The AICR reports up to 4tbsp a day safe for breast cancer prevention. Here’s a link to their fact sheet – it’s great!

Julie’s Expanded Answer:

I think it’s important for people to understand that you cannot get human estrogen in food. Plants DO NOT produce human estrogen!! And eating animals that have been treated with hormones does not mean that you are absorbing human estrogen from them either. Human estrogen can come from within your own body, or via synthetic hormone pills. That’s it!

Regarding this question, and a similar one about soy and estrogen, it’s important to understand where the facts are.

FACT 1: Some plants have phytoestrogens. Phytoestrogens are plant estrogens. Please do not get confused. These are NOT THE SAME AS HUMAN ESTROGEN!!! Plant estrogens just means that the chemical structure is similar to human estrogen. So far, studies suggest that plant estrogens are actually beneficial to our bodies. They have been shown to help lower cholesterol, and also compete with human estrogen in the context of estrogen receptors.

FACT 2: Flaxseeds are one of the top sources of lignans, which is one of the three major categories of phytoestrogens. In some studies it was shown that women who consumed higher amounts of lignans actually had lower rates of breast cancer.

FACT 3: You can also get lignans from other food sources, such as vegetables, grains, fruit, tea, coffee, legumes, nuts and seeds. All things that are really great for you!

FACT 4: Flaxseeds are a good source of Alpha-Linolenic Acid, an omega-3 fatty acid that is known to have anti-inflammatory properties. That means it’s good for your heart and for cancer fighting benefits! However, it’s not nearly as active as the omega-3 fatty acids you would find in fish or fish oils.

I find this quote from the fact sheet especially helpful for the breast cancer survivors out there:

“Tamoxifen is an adjuvant therapy for breast cancer that seems to work principally by competing with estrogen for binding to estrogen receptors. Health professionals often question whether the lignans in flaxseeds could interfere with tamoxifen. However, studies of mice injected with ER+ human breast cancer suggest that in both high- and low estrogen conditions (modeling pre- and postmeno-pausal breast cancer), flaxseed either enhanced or maintain the effectiveness of tamoxifen in decreasing tumor growth, decreasing cell proliferation and increasing apoptosis. However, no results of clinical trials of flaxseed use during tamoxifen treatment are currently available. Research is in progress regarding flaxseed use during treatment with aromatase inhibitors.”

Personally, I would be comfortable consuming it but if you don’t, there are plenty of other ways to get a nutritious diet. I would avoid the oil, or supplemental versions of flax since you would be missing out on all the great benefits of the rest of the flax seed.

If you want even more information than this, then you should really just read the fact sheet!!
– Julie