Flax Seed and Oil: Phytoestrogens, Phytic Acid and Pregnancy Risks

Flax seeds and flax oil have many benefits, but that doesn’t mean that you should be consuming large amounts of it.  I recently started researching flax, chia and hemp seeds for comparison and was surprised by a few things I found out about flax. There are plenty of resources discussing the positives about flax, so I thought I would share a little about the phytoestrogens, the phytic acid content and the pregnancy risks of flax.  I welcome your thoughts and experience with flax as well.

Most of us know the common healthy attributes of flax seed. Flax seed is an excellent source of omega 3′s and a great source of fiber. Other benefits often quoted include lowering cholesterol, protecting against heart disease,cancer and diabetes, and controlling high blood pressures  For more about the positives, check out Whfood.com’s article. and this one as well.

Sounds great, right?  Flax seeds seem to have proven themselves helpful in many studies, however there are still some concerns that remain and new concerns that arise. Here are a few to consider.

Flax Contains Phytoestrogen

You’ve probably heard of the debate regarding soy and phytoestrogens. Some people think it’s a positive, a growing number of people think it’s a negative. A phytoestrogen basically acts like or mimics estrogen in our bodies. I haven’t come across of a lot of information about the phytoestrogen found in flax so far, but I know that the phytoestrogen is bad news in soy!

Kimberly Hartke recently reprinted an article about the dangers of soy. It included this section.

“The fact is that the soy bean contains numerous phytoestrogens; a descriptive name for plant chemicals having oestrogenic effects. They occur in nature to help regulate animal breeding cycles and, in synthetic form, are used in farming for the same purpose. The ubiquitous birth control pill is, of course, the human synthetic version. At high dosage or over long periods phytoestrogens become anit-oestrogenic. Much higher doses are in chemotherapy to kill cancer cells.

The class of chemical compounds called phytoestrogens contains dozens of sub-classes, such as coumestans, lignans and sterols, each of which contains further sub-classes. Soy contains many isoflavones, including the sub-classes ernistein, coumestrol and daidzein.

Scientists have known for years the isoflavones in soy products can depress thyroid. As far back as the 1950s phytoestrogens were being linked to increased cases of cancer, infertility, leukaemia and endocrine disruption.

Charlotte Gerson, of the Gerson Cancer Clinic in the USA, has published detailed research (Gerson Clinic: Cancer Research, June 1, 2001 – 61 (11) : 4325-8) proving that the phytoestrogen genistein is more carcinogenic then DES (diethylstilbestrol), a synthetic oestrogen drug that was given to millions of pregnant women primarily from 1928-1971. Few would be unaware of the death and misery that particular drug inflicted on countless women and their daughters.”

So when I found out that phtyoestrogens were in flax as well. I sat up and listened! I should say that soy and flax contain different types of phytoestrogens, so they could have very different effects. Soy’s main phytoestrogen is isoflavones. Flax’s is lignans.  I should also mention that some studies seem to point to flax being able to help fight against breast cancer (which is very exciting). Though, I remain cautious because soy is also supposedly able to fight against breast cancer (and I am not a cheerleader for soy).  I will eagerly watching for more studies about flax and it’s effects on breast cancer.

But I do think that flax can have an effect on your hormones, especially if you are taking a higher amount. For example, a few friends have used seeds to help regulate their cycle, and flax is a key part of that program. In this study, flax was used to significantly reduce hot flashes in menopausal women. I would guess this has to do with it’s estrogenic effect.

So whether you think the phytoestrogens in flax is a positive or a negative, I think that it’s important that you know that it does contain phytoestrogens which can effect your hormones. Used correctly, flax can help with many hormonal imbalances, but that doesn’t mean we all should have a free-for-all flax feast (especially if you are a male!).  This is also important to remember if you are pregnant when the right hormonal balance is very important to maintain (most of us, by the way, have too much estrogen in our body, and not enough progesterone). This leads me to my next concern.

Flax oil has the potential to cause premature labor

A recent study in Canada studied over three thousand pregnant women, asking what natural supplements they took and then seeing what effect that had on their pregnancy. They found that those who consumed flax oil quadrupled their rates of premature labor.

That’s significant.

You should note that that link was found just for those who consumed the oil, not the whole seed. You should also note that this is just one study, and there needs to be follow up studies. But remember that it wasn’t a slight risk increase, it was a very significant increase. As someone who has experienced premature labor, you better believe I am going to be avoiding flax when pregnant!

By the way, a common cause of premature labor and miscarriages is having an imbalance of too much estrogen and too little progesterone. It does make me wonder if the phytoestrogen in flax has anything to do with the increased rates of premature labor. An interesting thought.

Finally, Flax Seed Contains High Amounts of Phytic Acid

You remember phytic acid, right? It’s the anti-nutrient that binds with many of the minerals and nutrients in grains and legumes. I talked about how to reduce them in grains here.

Well, my former understanding was that flax seed had low amounts of phytic acid. It doesn’t after all. It actually has very high amounts. In fact, it’s considered one of the “best” sources of phytic acid! In the book, Flax, By Alister D. Muir, Neil D. Westcott, they state that flax contains “significant levels of phytic acid”. This website which promotes phytic acid as a positive says that wheat bran and flax seed are the “best sources.”

All to say, stop making those low carb flax muffins! However, I did notice that Navita’s Naturals has a sprouted flax flour. That would take care of the phytic acid problem.

In Conclusion

Do I think that flax has benefits? Yes, I think it does. But I think that you need to be well informed about the benefits and concerns. I noticed that while the Weston A Price foundation does recommend flax seed and oil, they don’t recommend that you take large amounts. In fact, they have voiced concern over the trend of many to overdo flax oil. In one Q & A, Sally says that 1/2 teaspoon per day should be enough.

Don’t overdo flax.