Dr. Davis has succeeded in drawing attention to the dangers of wheat and the benefits of a low-carb diet beyond what I thought possible. He builds a convincing case against this new plant that he says shouldn’t even be called “wheat,” and he documents most of his arguments with supportive research. I was already avoiding most grains and decided to eliminate wheat after reading Wheat Belly. I have been following a low-carb lifestyle and writing about it for over 13 years, so it wasn’t a radical change for me.

I do have a major concern about both of the Wheat Belly books, however. Ten out of the 29 recipes in the original Wheat Belly call for flax, as do most of the recipes in the new cookbook. Flax meal has become a staple food for many who want to avoid wheat. It is used in gluten-free baked goods and as a flour substitute in low-carb foods. It is also used as a replacement for eggs in low-fat and vegan recipes and as a supplement to provide fiber and omega-3 fats. Many people are eating it in great quantities, thinking it is the ultimate superfood or, as one writer said to me, The most powerful food on the planet.

A closer look shows some pretty scary stuff about flax, rancidity, for one. Flax contains very fragile oils that are easily damaged by heat, light, air, and time. It should be stored in the refrigerator and used promptly. Only fresh, freshly-ground, ripe seeds are safe to eat, so obviously, cooking with flax is not a good idea.

Flax has a lot in common with soy, once the darling of the healthfood crowd. Both soy and flax contain estrogen mimics. (An extract of soy is used as hormone replacement therapy for treating menopause symptoms.) These plants produce hormones as a way to defend themselves from predators (like us) by disrupting the endocrine system of those who eat them so they can’t reproduce. Eating a lot of plant estrogens might not be such a good thing, especially for men.

Soy, a byproduct of the vegetable oil industry, has been heavily marketed as a health food since the 1990s. Flax seed comes from a type of plant used to make linen. Neither were staple foods in any traditional society. A 1998 study from Cornell conducted by vegan advocate and author of The China Study, T. Collin Campbell, reported that the Japanese ate less than 2 teaspoons of soy protein per day. (Celibate monks, who use soy and a vegetarian diet to reduce libido, are an exception.)

In addition to soy, which is already ubiquitous in our food supply, pesticides, plastics such as Bisphenol A (BPA), and chemicals like perfluoroctanoic acid (PFOA), used in food packaging and coatings, also contain these hormone-like chemicals and the dose is cumulative. BPA and PFOA, the so-called gender benders, have been linked to breast cancer, fertility problems, and other hormone related illnesses.

While flax and soy both contain estrogen mimics, according to Web MD, flax contains 800 times as much of these hormone-like chemicals as soy. In fact, flax contains more plant estrogens than any other plant food.

We are already experiencing an epidemic of infertility along with our other epidemics of obesity, diabetes, autism, auto-immune diseases, explosive rage disorder, and more. You may have heard that American men have one-third the sperm counts of their grandfathers and that by 2050, for the first time in modern history, scientists are predicting that our population will start to go down. Add in all the men who are on statins to reduce cholesterol (testosterone is made out of cholesterol), and it is easy to see why the same companies that sell statins also sell Viagra and Cialis.

There is conflicting evidence about plant phytoestrogens. Some think they may be helpful, some think they may be harmful, and most of the articles about them end by saying, more research is necessary. But this much is clear: This is potent medicine and the dosage is very important!

How much is a dose? Even the sites that recommend flax as a supplement tell you to consult your doctor to determine how much to take. The USDA says that 3 tablespoons of flax a day is a safe level. Some of the recipes in the Wheat Belly Cookbook contain more than that in a single serving.

Below is a sample of warnings about flax from various organizations:
~from MayoClinic.com: http://www.mayoclinic.com/health/flaxseed/NS_patient-flaxseed/DSECTION=safety
“Taking flaxseed or flaxseed oil by mouth may cause a person with bipolar disorder to experience mania or hypomania….

Raw flaxseed or flaxseed plant may increase blood levels of cyanide, a toxic chemical….

Flaxseed may cause low blood pressure. Caution is advised in patients with blood pressure disorders and those taking drugs, herbs, or supplements that affect blood pressure….

Based on the available evidence, flaxseed, which contains alpha-linolenic acid (ALA), should be avoided in patients with prostate cancer or those at risk for prostate cancer….

Use flaxseed and flaxseed oil cautiously in patients with elevated triglycerides, as these agents may raise or lower triglyceride levels.”

~From DietaryFoodFiber.com: http://www.dietaryfiberfood.com/nutrition/flax-seed-side-effects.php
“One study reports that the menstrual period may be altered in women who take flaxseed powder by mouth daily. Due to the possible estrogen-like effects of flaxseed (not flaxseed oil), it should be used cautiously in women with hormone sensitive conditions such as endometriosis, polycystic ovary syndrome, uterine fibroids, or cancer of the breast, uterus, or ovary. Some natural medicine textbooks advise caution in patients with hypothyroidism, although little scientific information is available in this area….

Raw flaxseed or flaxseed plant may increase blood levels of cyanide, a toxic chemical (this effect has not been reported when flaxseed supplements are taken at recommended doses.)” (Are they talking about a few spoonfuls of seeds or a little capsule of oil? We don’t know. JBB)

~From Livestrong.com: http://www.livestrong.com/article/306658-flaxseed-side-effects/
“A study on the Effect of Flax Seed Ingestion on the Menstrual Cycle, published in a 1993 Journal of Clinical Endocrinology and Metabolism, found that a woman’s menstrual period might be altered if she consumes flaxseed products daily….

Because flaxseed has estrogen-like effects, it may result in a worsening of conditions such as uterine, ovarian and breast cancers; uterine fibroids; polycystic ovary syndrome; and endometriosis, according to the Natural Medicines Comprehensive Database of the National Institutes of Health. Women who have hormone-sensitive conditions should probably avoid using large amounts of flaxseed. It can also alter the effects of oral contraception.”

Please do your own research and decide for yourself whether you want flax in your diet and if so, how much is too much.

The Wheat Belly Cookbook does an excellent job of explaining why we need to ditch wheat and other high-carb foods and makes the case that modern wheat was not adequately tested for human consumption. But flax hasn’t stood the test of time either. Is flax as risky as wheat? Perhaps not, but if you eat too much of it, you may just be replacing one untested food with another. Women and girls may be at risk for hormone imbalances and the guys may be trading a wheat belly for flax boobs and Viagra. Still not a pretty picture.

About Chia: I tried to find a replacement that worked as well as flax in these recipes before I posted this review so I could suggest an easy fix. Chia seeds are the best candidate I have found so far, but the recipes may still need some tweaking. I made a good loaf of Basic Bread by substituting one-half the amount of chia for the flax, but my chia version of the Flaxseed Wraps needed a complete overhaul.

Chia seeds are similar to flax but have some very important advantages. Both attract water and form a gel, making it important to drink lots of water and not to take some medications when eating them, because they can entrap pills and keep them from dissolving. Chia seeds contain complete proteins and two-thirds of chia oil is the beneficial omega-3 variety. This is the same fragile oil found in flax, but chia also contains large amounts of natural antioxidants to keep it fresh, even after it is ground. Chia has no phytoestrgens or toxins and unlike flaxseed, chia can be kept for long periods without becoming rancid. Chia’s nutrients are bio-available from the whole seed; they don’t have to be ground like flax in order to be digested.

(c) 2013, Judy Barnes Baker, www.carbwarsblog.com

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Judy Barnes Baker

The working title for my first book was, “You’ll Never Know What You Are Missing.” It summed up my goal: to make eating for health synonymous with eating for pleasure. Once you discover the secret, you will find that the very best food for weight management, longevity, the treatment and prevention of disease, and over-all health and happiness is also the most sumptuous, satisfying, and indulgent way of eating the world has to offer. You are invited to the feast. Enjoy!


  1. Flax? SOOOOO many Omega 6's… My heart just sank!

  2. Anne, eat fish instead! 🙂

  3. It seems that flax has gotten even more popular as of late, as I hear a lot more about it in my CrossFit members' diets. I haven't encouraged it, nor have I ever been completely against it. But after this article it seems I should look more into the latter. Thanks for your insight and lookin forward to learning more about it so I can best help my members.

  4. Maybe I'll just eat nothing, then I don't have to worry about what's good or bad. So depressing, but thanks for posting the reference data.

  5. Thank you for posting but this has seriously upset me 🙁 Already having a hormone imbalance, I was quite shocked reading the piece… Any idea if preparation (like using it in baking) lessens the phyto-oestrogens? I eat a porridge of two tbs flaxmeal (I grind my own but did not as yet keep it in the fridge) with 1 tbs chia and one tbs hemp seed daily and have had menstrual problems other than normal the last few months….

  6. Sandi, don't dispair! We can make good food without flax. By the way, tests have shown that people who eat a low-carb, ketogenic diet lose more weight than those who eat NOTHING at all!

  7. Nikki, I doubt that cooking reduces the estrogens in flax and heat damages the oils so they become toxic. Can you just use more chia?

    Also, you might want to check the omega-6 levels in hemp.

    Thanks for the comment.

  8. I appreciate all the information you presented here. Dr Mercola talked about this a couple of years ago, and I've since backed off on flaxseed. I decided to use variety, especially chia seeds. Sometimes almond flour, coconut flour, ground chia seeds, etc.

    I remember years ago reading that by constantly eating the same thing, we can induce allergies. So I figured it wouldn't hurt to mix it up, and not go overboard on any one ingredient.

    After reading this, methinks I'll demote the little flaxseed to the bottom of my list. 🙂

  9. Haha, Rettakat, you're funny! Wow, what an informative piece, Judy. I myself stopped flax ages ago when I did some research after having one or two funny turns that may or may not have been due to the flax…but at least it got me off the flax. Thank you for creating awareness. I need to create awareness about coconut oil next. That is the next darling in the low-carb world that should come off its pedestal.

  10. Don't keep us in suspense, Jennifer! Tell us about coconut oil.

  11. I'm so glad you wrote this. I had a bad experience with ground flax seed 7 years ago when I was 65. I had read somewhere that it was good for women's health so I made a batch of muffins with a tablespoon or so of ground flax per muffin. (This was before I adopted low-carb eating.) I got mild hot flashes when that batch ran out so made another batch. By the time I'd finished the second batch something didn't seem right so I quit flax "cold turkey." For almost a week after that I had the worst hot flashes I'd ever had with so much sweat pouring down my face I had to mop my forehead every few minutes to avoid getting so much sweat in my eyes I couldn't see.

  12. Thanks to all of you for the comments.

    Me: That's an amazing story. Thanks for sharing it. I have had a problem with hot flashes too (mine are fibromyalgia related), so I know how terrible they can be!

  13. Hemp seed seems to be a new food on the block, although I don't know re its gelling properties or whether or not it contains phytoestrogens.

  14. Marta, hemp doesn't gel at all. It is also very high in omega-6 oils, although the companys that sell it claim it has the right balance of 6s to 3s. Those of us on low-carb are not over-loaded with omega-6 anyway, so some is probably OK. Here is an article about it (from a seller, so maybe not impartial and certainly behind the science about saturated fat): http://www.drbronner.com/pdf/hempnutrition.pdf

    Hemp is tasty and has a very neutral taste. I have used it a time or two, and so far, I haven't seen any warnings about it (probably shouldn't grow your own, though, or you might get arrested!)

  15. Interesting article Judy.
    I have just finished reading The Brain Trust Program by Dr. Larry McCleary which contains excellent information of Menopause and Hot Flashes. He recommends flax seeds because they are rich in ALA which the body can turn into DHA and EPA but he does not specify how much to take. I have written to him to find out more information on this controversial subject and will let you know if I do get a reply.

  16. Joan: I'm a fan of Dr. McCleary too and would love to hear what he has to say. Forward a link to my article to him, as most people don't seem to be aware of anything but the pro-flax material that is out there and they often don't read to end of the articles, which often include a warning about the dangers of taking too much.

  17. Judy , I did ask Dr. McCleary to comment on your article and sent him the link last week.
    I checked out Dr. Davis Carrot Flaxseed Muffins and he only uses 2tbsp.approximately 28g for a recipe of 12 muffins which I feel is quite reasonable. The upper limit of flaxseed I believe is 25g per day

  18. Joan, let me know what he says.

    Yes, some of the recipes don't have a lot in one serving, but some do. The wraps and the cereal, for example, have 1/4 to 1/2 cup per serving, if I remember correctly. I think there should be a warning about eating multiple servings per day, which a lot of people are doing.

    Remember too, that the reason plants contain compounds that are like human hormones is to protect themselves from us. Livestrong.com says the biggest threat is to pregnant women who may miscarry or have children with birth defects in their reproductive systems. I spoke with someone after this article came out who said a relative had 3 miscarriages in one year after starting a Paleo diet with a lot of flax. (She already had other children and had not had problems before.) That's exactly what plant estogens are supposed to do—it's the plant's revenge—we kill their babies (seeds), they try to kill ours.

    There are other sources for omega-3oils for those who don't want to eat fish or take a supplement that do not carry these risks.

  19. Flax causes me to have sinus congestion and often sinus infections so I cannot eat it anymore. Also cant' eat any type of grain. Such a bummer.

  20. Unknown:
    That could be a blessing in disguise!

  21. I was so pleased to find this blog! I recently purchased the Wheat Belly cookbook and my heart just sank when I read through all of those flax laden recipes. I've always known that flax was a phytoestrogen that must be consumed with great caution. Our environment is already chock full of xenoestrogens (chemical compounds that have an estrogen-like effect on our bodies). The last thing we need is to add more to our food source….

  22. Welcome, Linda. I am glad you found your way here and appreciate your comments! Dr. Davis considers flax to be a "free food" and says to eat as much of it as you want. I hope you will help me sound the warning.

  23. I had my first experience with flax a couple of days ago and it was horrible. I have IBS and had a terrible reaction to it.

    Thank you for the information.

    • Judy Barnes Baker

      You are welcome, Anonymous. It’s lucky that you weren’t able to tolerate it long enough to have other problems!

  24. So much conflicting evidence from all sides! I’ve heard praises sung for so many things that someone else claims is harmful, it’s hard to know where to turn (for example, I’ve read a number of studies and articles promoting phytoestrogens and/or flax for PCOS).

    Frankly I find posts like these mildly alarmist, and even somewhat detrimental – if nothing is proven either way, I'm not entirely sure it's wise to so strongly vilify flax (or anything!) one way or the other. I think probably too much of anything is bad!

    For example, someone may eat flax daily and see none of these issues – or some might see some of these issues, but there are so many other variables involved in daily life, you couldn't know whether flax was the culprit or not. And what might benefit one person might be downright dangerous for someone else!

    I enjoy flaxseed, and have found that it's a great substitute for a lot of the things I now tend to avoid. I eat a fair amount pretty often.

    And I know you wrote this to help and inform, but without proper evidence of anything, I might just need to compromise and weigh the risks against the benefits. Thanks for the read, however. I can see this is complicated stuff!

  25. Hi Sara. Thanks for the comment. Yes, people vary in how they respond to eating flax. but I don't think it is alarmist to warn them that it may cause adverse reactions, especially if it is eaten in large amounts.

    I have had a lot of feedback here and on other sites that confirm that many people have had problems, some very serious, and there may be many more who have had negative reactions but haven't made the connection because flax is usually praised as a super food. I think anyone who sells or recommends flax seed needs to include a warning.

  26. Michelle, the only problem I see with the ingredients in his recipes is the flax, although I have heard that some of the recipes don't work as written. I think Carolyn Ketchum has "fixed" some of them for her readers. I'd suggest reading the Wheat Belly and Grain Brain books for the science and getting your recipes elsewhere. You'll still find a lot of flax in most of the gluten-free books, though. You'll have to filter those out. All my recipes are flax-free.

    The backbone of the Wheat Belly Cookbook is his flax wraps. My flax-free wrap recipe is here: http://carbwars.blogspot.com/2013/07/low-carb-gluten-free-flax-free-flexible.html

    I have several other flax-free breads here on my blog. If you search for "pita," Crispbread," and "biscuit" you can find them. There is also a chocolate granola recipe that you might like.

  27. I just started using the Wheat Belly cookbook and enjoy the recipes but also have been using ground flax daily as a hot cereal with coconut milk unsweetened. I am so disappointed that this Dr. uses it as I have started my period 2 weeks early and have bad breath, bad taste in my mouth and am fatigued. I have also gone off of all wheat products as well. Can I trust this guys cookbook if he published it using so my flax?

  28. One more thing, Michelle: The bad taste in you mouth is the result of ketosis. It will happen any time you are losing weight no matter how you do it. Most people experience this during the induction phase of a low-carb diet but it goes away in the later stages.

  29. I just started using the Wheat Belly Cookbook and flax daily for a week. I started my period and have had bloating, abdominal cramping and a really bad taste in my mouth along with fatigue. I was so excited to go wheat free and low carb then I stumbled on this while on Amazon. I am grateful but at the same time now I don't trust his cookbook.

  30. I have been eating 2 1/2 TB of freshly ground golden flax seed every morning to try to counter act hot flashes. Is this a dangerous amount? Your article doesn't state what amount is too much?

  31. Melissa, I can't tell you what your dose should be as that would depend on the individual. If you are taking it as medicine, you can ask your doctor to recommend how much you need. If you have any adverse symptoms, then it's too much.

    Our government says that 3 tablespoons per day is a "safe" amount, but I have heard from people for whom that much caused unwanted side effects.

  32. My jaw dropped when I read your post, I have been consuming flax seeds regularly for years. In the past couple years I have had alarming changes in my cycle and developed ovarian cysts. I have been systematically changing my diet over this time trying to figure out if something I was consuming contributed to my ailments. (soy was the first to go). I consider myself extremely healthy and not a follower of fad diets but common sense, though I do avoid carbs and processed foods because they make me feel bad. I've become vary aware of how food affects how i feel but I had NO IDEA flax could be causing my woes, I am throwing out my seeds today and I hope a few months from now I will finally find some relief. I really really hope it is the flax seeds!!!

  33. Sara S: hi and thanks for sharing your story. Please write again and let us know if eliminating flax resolved your problems.

    More and more foods with flax are showing up for sale with nary a word of warning anywhere! Most people seem to know about the estrogen in soy, but few know that flax has much, much more than soy.

  34. Ms. Barnes-Baker, I'm late to this flax-seed discussion because I've only read your review of the Wheat Belly book today via a link at amazon, but I do remember reading that even if flax weren't so darned (IMO) dangerous, it requires a lot of biochemical fixing by the human body before it can be utilized (IF it even really can be utilized). I don't remember now where I read that but the confirmation that it requires transformation by the human metabolism into something that can be "utilized" (questionable?), can be found at Dr. Mike Eades website:

    "Flaxseed oil has high levels of alpha-linolenic acid (ALA), an omega-3 fat. When consumed ALA enters the fatty acid pipeline and is desaturated and elongated by the appropriate enzymes until it is partially converted to EPA then to DHA. So flaxseed oil does increase the levels of EPA and DHA, but, we think, not nearly as much as does fish oil, which already contains the preformed EPA and DHA we need.
    Over the years we’ve taken a lot of flack (flax?) from various people and companies that sell flax oil. We’ve been inundated with testimonials from people who have been healed of—it seems—every disease known to man simply by taking flax oil. I don’t know why, but it seems that flaxseed oil lovers have an almost religious affinity for the stuff. Despite it all, we’ve hung tough and stuck with out recommendations for fish oil instead of flaxseed oil simply because a) it makes more sense biochemically, and b) our patients seemed to do better on fish oil."
    This link will take you to the article: http://www.proteinpower.com/drmike/uncategorized/fish-oil-versus-flaxseed-oil/

    I respect the Drs. Eades' and your opinions more than all the pro articles and suppositions on flax.

    The issues you've brought up in your review not only are valid IMO but it's also great work, for which I'm grateful because you go way beyond carb craving.

    I used flax in a "no wheat" "bread" recipe. The bread was tasty but it caused immediate problems. Since then I've learned that I can make an acceptable version using 1 TBSP coconut flour as replacement for 4 TBSP ground flax seed. I don't consume this replacement bread very many times per month, maybe once or twice, but it doesn't cause carb cravings and it proves I can do better than flax in most recipes by substituting coconut flour.

  35. Anonymous: Great comment! I wasn't aware that Dr. Eades had posted anything about flax; I certainly would have quoted him if I had known. I hope you also posted your comment on the Wheat Belly Amazon page. This is an important issue and posting book reviews is a great way to reach people.

  36. Just found this site and do not know what to make of it. For a couple of years I have been taking 3 tablespoons of a flaxseed formula daily. It is from Golden Standards and has been helping raise my GFR (kidneys). Thus keeping me from Dialysis. However, I now have diarrhea constantly, plus much discomfort and pain in my gut. So I do not know what to do at this point. The formula product is call “Kidney Stuff” and has now Cholesterol and Sodium. Is rich in Omega3’s and Lignans. Is a source of Folate, Magnesium. Copper, Dietary Fiber and Manganese and is non GMO. It did raise my GFR and has kept me away from Dialysis. However, since I have stopped taking it a couple of months ago, I do not know where my GFR rate presently is. Perhaps I am now much closer to Dialysis than I know.

    I am wondering why people no longer write on this page. Do not write me on my Facebook page, I seldom go there. I respond to email best and notifications of replys to various things on my email.

    • Hi Sally. I’m so sorry to hear of your problems. I think you can find supplements that have the beneficial qualities of flax without the horrible side effects. The lignans are the source of estrogen and anti-nutrients in flax. You can get omega 3s from Krill or fish (much better sources) or from chia seed or even from flax oil that has not had the lignan added back, but only use flax oil if it is ery fresh as it goes rancid easily. The magnesium, copper, etc. come in supplement form.

  37. Judy….Thanks for your reply, very much appreciated. Useful information! There is a grower of Flaxseed about an hour North of me. I think I will stop there and see what he or she has.

    I knew a Judy Barnes in high school….wonder if that was you. Are you from Michigan?


    • Sally Borghese: Let us know what you find out. Maybe you can convince him to sell it as birdseed rather rather than human food!

      No, I went to high school in West Virginia.

      Thanks for the comment.

  38. Thanks for the article. Do you know if cold-pressed flaxseed oil (rather than the whole seed) contains the phyto-oestrogens?

    • tammy: No, it is my understanding that the oil by itself does not contain the phyto-estrogens, BUT often the lignans from the seeds have been added back into the oil because they are considered “healthy!” Be aware though, that the whole seeds are not easily digested, so you will not get any of the benefits of the omega-3 fats in the whole seeds (which is one of the main reasons flax is considered healthful). Whole flax may have a laxative effect because of the mucilage, but that is all.

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