Soy and Seizures: Bad News for the Soy Industry

“Soy Exacerbates Seizures in Mouse Models of Neurological Disease” is the title of an important study that came out last fall in the Journal of Alzheimer’s Disease.1 Soy has long been associated with ADD/ADHD, depression, anxiety, dementia and other mental health issues. 2 Now it appears that soy can aggravate seizures as well. Cara J. Westmark, PhD, and her team at the Waisman Center for Developmental Disabilities at the University of Wisconsin, Madison, pull no punches when they warn, “These results have important implications for individuals on soy-based diets.”3


The average American, of course, would not describe his or her diet as “soy-based,” yet soy ingredients are found in more than 60 percent of packaged and processed foods and nearly 100 percent of fast foods. The plant-based diet fad has furthermore encouraged many health-conscious Americans to substitute soy products for both meat and dairy. And although animal products would appear to be “soy free,” most commercial and health-food store eggs, milk, and flesh foods contain residual isoflavones from soy-based feeds.4

Infants on soy formula—currently about 25 percent of bottle-fed babies, according to the American Academy of Pediatrics—are on soy-based diets because they rarely receive anything else to eat, which has led the Israeli Health Ministry, the French Food Agency, the German Institute of Risk Assessment, and the British Dietetic Association to warn parents and pediatricians that soy formula could jeopardize brain and body development and should be used only as a last resort.5,6

Another captive population is prisoners. The Weston A. Price Foundation is currently suing the state of Illinois on behalf of prisoners who have suffered grave damage to their digestive tracts and thyroid glands due to a high soy diet containing up to a whopping 100 grams of soy product and 100 mg of isoflavones every day.7

The level of seizures occurring among today’s Illinois prison population is unknown. However, a 1978 study in JAMA reported seizure disorders at 1.9 percent among prisoners in Illinois, three times the level found in the general population.8 Although prisoners in the 1970s may have been spared the extremely high 100 grams of soy protein served up today, they most likely endured economy fare such as hamburger and other rations extended with soy grits, textured soy protein and soy flour. Whether soy on the menu might have caused such a high percentage of seizures is unknown. Prisoners, after all, may well have suffered for years from neurological damage that led to violent tendencies, crime and incarceration. Whether they were already seizure-prone individuals or not, the research of Westmark and others suggests their high soy diet could only have made matters worse.


Those who think seizures are rare and only happen to other people need to think again. According to Dr. Westmark, one in every ten Americans will experience a seizure during their lifetime.9 According to the Mayo Clinic, seizures may result from many disorders affecting the brain. Best known is epilepsy, a disease characterized by seizures, but seizures can signify metabolic disturbances such as hypoglycemia or dangerously high or low levels of sodium, calcium, magnesium or water. Seizures can also be triggered by brain injury, infections such as meningitis, tumors, lupus, stroke and high fevers.10 In many cases, the cause of seizures is unknown, and the underlying molecular mechanisms that initiate and propagate seizures are not well understood.11

Patients with Alzheimer’s disease, Fragile X syndrome, Down syndrome, and autism are particularly susceptible to seizures,12 and the focus of much research at the Waisman Center of Developmental Disabilities has been on the myriad ways drugs, diet and genetic manipulation can affect amyloid beta levels, seizure threshold and behavioral phenotypes.13 In an editorial entitled “Concocting the Right Diet for Brain Health” published December 2011 in Translational Medicine, Dr. Westmark expressed concern about the risks of soy: “The prevailing view is soy is healthy, but much remains to be learned regarding its effects on brain development and function.” She furthermore warned:

There is a paucity of studies on the effects of phytoestrogens on fetal and early childhood development; yet, twenty-five percent of infant formulas are based on soy protein. Considering body weight, these infants are getting 6-11 times the dose of phytoestrogens necessary to exert hormone-like effects in adults. There are epigenetic changes associated with a soy-based diet in monkeys suggesting the potential to greatly alter gene expression. We have observed significantly elevated seizure rates in mouse models of Alzheimer’s disease, Fragile X syndrome, and Down syndrome when juvenile mice are fed a soy-based diet. Our data suggest that soy-based infant formulas may lower seizure threshold particularly in babies genetically predisposed to developmental disorders. Thus, understanding the negative effects of soy phytoestrogens and modulating intake during pregnancy and infancy could prevent neurological damage during critical periods of sensory development.14

What’s most surprising about this research is that the mice fed a casein-based refined diet showed “decreased amyloid beta and attenuated seizure rates.” Casein is a fractionated milk protein that is high in the amino acid methionine and seriously deficient in cysteine. It has such a poor nutritional profile that the soy industry has found it a reliable “control” to use in studies where the intent is to make soy look good. Indeed research at the Faculty of Agriculture, Shizuoka University in Japan, has shown that casein will significantly raise total cholesterol levels and lower HDL levels compared to other proteins.15,16 Consequently most studies used to support the FDA’s 1999 soy/heart disease health claim are deeply flawed because of the routine use of casein as the control.17 In the case of the research done at the Waisman Center, the rats fed a chow comprised of casein, sugar and cornstarch came out on top, and the data clearly indicated “soy isoflavones are associated with decreased seizure threshold.” Indeed soy-restricted diets reduced seizures in multiple lines of mice bred for diseases in which they would be prone to seizures.

To test the hypothesis that soy isoflavones promoted the seizures, the researchers determined to feed some of the mice chows that were supplemented with genistein and/or daidzein, the two isoflavones found in the highest quantity in soy.

After just three days of treatment with the standard soy protein chow, the group of specially bred “Alzheimer’s disease” mice responded with “wild running” and audiogenic seizures.18

In plain English, audiogenic seizures are seizures brought on by the sound of an alarm. “Wild running” refers to an out-of-control style of running that progresses to loss of the righting reflex, tonic hind limb extension, and other signs of seizure, often followed by death. “Righting reflexes” bring the body into a normal position in space and resist forces acting to displace it. They allow the animal to orient itself and regain its balance. Mice that do not die from the seizures regain the righting reflex and appear normal within a few minutes.


The researchers identified daidzein as a component of soy protein that elicited a strong wild running phenotype in wild type mice—that is, normal mice as found in nature. Three days of eating chow spiked with daidzein induced plenty of wild running, but no statistically significant increase in seizures. As yet, the researchers have not identified other components found in soy protein that work in tandem with the daidzein to trigger the progression into seizures and death. As for the Alzheimer’s mice, soy protein increased seizures but daidzein did not, though there was a strong trend for increased wild running in the females.19

Interestingly enough, daidzein but not genistein led to increased “wild running.” The non-soy chows enhanced with genistein or the combination of genistein and daidzein, failed to provoke seizures in the wild type or Alzheimer’s disease mice. Indeed the genistein may have counteracted that,20 a finding that will surely lead the soy industry to put a positive spin on the study with a headline such as “soy genistein stops seizures.”

To understand the mechanism underlying the activity of the soy isoflavone daidzein, the researchers performed in vitro experiments in which they “assessed dendritic AβPP expression in primary, cultured, wild type neurons treated with daidzein or genistein” and “found altered AβPP expression.” They concluded both the in vivo and in vitro findings “have important implications for individuals on soy-based diets as well as for the rodent model.”21

It is also extremely interesting that daidzein alone appears to have caused the seizures and increased Aß processing. According to neurosurgeon and excitotoxin expert Russell Blaylock, MD, “this is a mechanism unrelated to excito-toxicity” though it is possible “daidzein may trigger excitotoxicity indirectly—say by activating microglia.”22 Much research shows seizures are generated by MSG and other excitotoxins, which are widely found in modern soy products. Glutamate, for example, is created as a byproduct of the industrial processing methods used to manufacture soy protein isolate and other fractionated protein products. In addition, food manufacturers often add MSG—often hiding under the alias “natural flavoring”—to improve taste and smell.23 However, this would also be true of manufacturing methods used to produce acceptable tasting casein products.

In terms of seizure control, it would seem useful to optimize the daidzein-to-genistein ratio in soy feeds and soy foods, but that’s easier said than done. Isoflavone content varies greatly from one batch of soybeans to another, much to the dismay of the soy industry, which finds it cannot reliably minimize risks or maximize alleged benefits. Predicting isoflavone content remains elusive because the levels are influenced by many factors, including crop year, geographical location, number of daylight hours, temperature, humidity, rain, fertilizers, types of pathogens and the plant’s response to attack or disease.24

The significance of research on diet and seizures cannot be overstated. The Westmark study provides sobering figures: Seizures occur along with Alzheimer’s disease in 10 to 22 percent of patients; Fragile X Syndrome, 18 to 23 percent; Down syndrome, 8 percent; autism, 21 to 38 percent; and traumatic brain injury, 53 percent.”25

Expanding on Dr. Westmark’s warning in Translational Medicine about the risks of high-soy diets during pregnancy, infancy and early childhood, the current study includes this warning:

“High exposure to estrogenic compounds during fetal and early childhood development through soy-based food products could disrupt the function of the natural steroid hormones and contribute to the high incidence of seizures associated with many childhood, neurological disorders including autism and FXS (Fragile X Syndrome). Understanding the role of soy constituents, such as daidzein, on AβPP (amyloid-β protein precursor) synthesis and metabolism and modulation of intake during pregnancy and infancy could reduce seizure incidence and prevent neurological damage.”26

Westmark and co-authors furthermore report work in progress in which the data—as yet unpublished—point to higher incidence of febrile seizures in autistic children fed soy-based formula.27

The current study states that more research is needed and concludes, “Thus, a clearer understanding of the environmental factors, such as soy, that modulate synaptic AβPP levels may provide a dietary intervention to reduce Aβ levels and seizures.”27

What to do in the meantime? Those smart enough to value their brain health will say “better safe than sorry” and cut way back on soy!

The author’s gratitude goes to Sylvia Onusic, PhD, for research assistance.


1. Westmark CJ, Westmark PR, Malter JS. Soy-based diet exacerbates seizures in mouse models of neurological disease. J Alzeimer’s Dis. 2012 Oct 3. [Epub ahead of print]1–104: 20.

2. Daniel, Kaayla T. The Whole Soy Story: The Dark Side of America’s Favorite Health Food (Washington DC, New Trends, 2005) 251-258, 307-308, 355, 371-372.

3. Westmark et al.

4. Daniel, Kaayla T. The Soy-ling of America: Second Hand Soy in Animal Feeds This article can also be found at and

5. For more information about the Israeli, French and German warnings: ;;

6. Daniel, Kaayla T. The Whole Soy Story, 353-354.

7. For more information about the lawsuit:;;;;

8. Lambert NK, Young QD. Increased prevalence of seizure disorders among prisoners. JAMA, 1978; 239 (25); 2674-2675. doi:10.1001/jama.1978.03280520046016.

9. Westmark et al.


11. Westmark et al.

12. Ibid.


14. Westmark, Cara J. Editorial: Concocting the right diet for brain health. Translational Medicine, 2011, 1:3.

15. Sugiyama K, Ohkawa S, Muramatsu K. Relationship between amino acid composition of diet and plasma cholesterol level in growing rats fed a high cholesterol diet. J Nutri Vitaminol (Tokyo), 1986, 2, 4, 413-433.

16. Sugiyama K, Muramatsu K.J Significance of the amino acid composition of dietary protein in the regulation of plasma cholesterol. Nutr Sci Vitaminol ( Tokyo). 1 990, 3 6 S uppl 2:S105-10.

17. The Weston A. Price Foundation submitted a 65-page petition to the FDA asking the agency to retract the 1999 soy/ heart health claim, written by Kaayla T. Daniel, PhD, and signed by Kilmer S. McCully MD, Mary G. Enig, PhD, Galen D. Knight, PhD, and Sally Fallon Morell, president of the Weston A. Price Foundation. It is available online at:

18. Westmark et al.

19. Ibid.

20. Ibid.

21. Ibid.

22. Email from Russell Blaylock, MD, to Kaayla T. Daniel, PhD, October 7, 2012.

23. Daniel, The Whole Soy Story, 128.

24. Daniel, The Whole Soy Story, 295-299.

25. Westmark et al.

26. Ibid.

27. Ibid.





What’s Tofurky? Is it truly an incredible and revolutionary product?
It’s a vegan “roast” made primarily from tofu and wheat gluten. It smells strange, is oblong shaped, and said to taste like turkey, at least by vegans who’ve either never eaten real turkey or have very distant and feeble memories of having eaten turkey.

According to Turtle Island Foods, Tofurky is a gourmet vegan “roast and gravy” product made from “a revolutionary
tofu-wheat protein blend, known for its incredible, turkey-like texture and flavor.” Is it really “incredible” and
It might seem so if you’ve been dining on Approximeat, Roast Almost, Veat, Soyloin, Sham Ham or Wham.

Tell me about that ingredient “vital wheat gluten?”
It gives the Tofurky creature its signature wet and wild look. Having seen the creature naked and out of its box, I’d describe its body as doughy, gluey, pasty and corpse-like. Not very appealing and certainly not vital. Only a gluten for punishment would recommend it, given how many people today suffer from gluten sensitivity and celiac disease.

If you aren’t gluten sensitive, would Tofurky be a good way to “practice safe soy” this Thanksgiving?
No, with a name like that you could die laughing . . .

Do you think it has health benefits?
Absolutely. The taste and smell would keep you from overeating!

Seriously, isn’t it loaded with soy and flavored by MSG?
Hard to believe, but Tofurky actually has few flavorings compared to most meat analogue products and the Turtle Island company prides itself on rejecting spices with MSG. The company also uses no soy protein isolate, soy protein concentrate, hydrolyzed plant protein, textured vegetable protein or other modern, industrialized soy proteins manufactured using high temperatures, high pressure, acid and alkaline baths and hexane solvents. And Turtle Island takes care to use only non-GMO ingredients. The biggest problem by far is the wheat gluten! That’s the second ingredient, after water, which is the first. I’m also no fan of canola oil though I’m glad the canola oil in Tofurky is non-GMO.

Canola oil in Tofurky? Why not soy oil?
Soy oil’s in there too as it comes naturally in the tofu. I guess they decided there was no reason to soy-l it more! The added lube comes from canola oil, and the idea that it’s healthy is a great con-ola. If you don’t want the Tofurky bird to dry out, you are instructed to baste it with olive oil during the roasting process.

Sounds like a lot of oil. I thought the Tofurky was a lowfat bird?
Hardly. The creature is a shapeless blob with no bones or muscles whatsoever. It’s so fat it can’t even move unless you bind it tightly with shrink wrap, put it on top of a hill and give it a push.

How good is the fat in a real turkey?
No good at all if you are talking about supermarket brands “buttered up” with injections of soy oil , water and MSG. The problem is there’s no real butter in there!

How’s the fat found naturally in turkey?
Dr. Mary Enig says the fatty acid profile of turkey meat depends on the source, and it varies depending upon the diet fed the turkey. Typical fatty acid composition of turkey fat in the U.S. is less than 1 percent myristic acid, 22 percent palmitic acid, 6 percent palmitoleic acid, 6 percent stearic acid, 38 percent oleic acid, 22 percent omega 6 linoleic acid and 1 percent omega 3 linolenic acid.

People are always surprised that poultry contains so much monounsaturated fat. The oleic and palmitoleic acids together come to 44 percent monounsaturates. These figures would probably not change much with the organic turkeys sold in the chain health food stores because they are still fed corn and soy, just not GMO corn and soy. Few of those turkeys spend enough time in the great outdoors to be considered free range. Best to get heritage-breed turkeys that hunt and peck and eat bugs, worms and grass in the wild. The omega-3 and EPA, DHA fatty acid levels in those turkeys are much improved.

If you were going to serve Tofurky, how would you improve the taste?
Wrap it well with bacon and roast. Use real bacon, not fakin’ bakin, of course. Eat the bacon, hide the Tofurky in your napkin and toss.

Do the PETA folks like Tofurky?
You betcha! Last year PETA campaigned to rename Turkey, Texas, Tofurky, Texas. The town demurred even though PETA offered a full-course vegan Thanksgiving meal for the entire town if they changed their name. I think the gun-totin’ Texans must have fired at the PETA people because this year they didn’t go back.

What did Dr. Seuss think of Tofurky?
Dunno, though I think he kept a flock of Australorps x Ameraucana hens for the green eggs he liked with his ham. If he’d actually met a Tofurky, I think we’d have deathless prose such as, “Why did Tofurky cross the road? Did he cross it with a toad? Yes, Tofurky crossed the road, but how it crossed I’ve not been told.”

Tofurky doesn’t have a leg to stand on so how could Tofurky possibly cross the road?
Tofurky could roll if given a good push. If it crossed on its own, we’d have to ask, did Tofurky really cross the road or did the road move under Tofurky?

Why did Tofurky cross the road?
To see Gregory Peck?

Gregory can no longer peck. Why did Tofurky cross the road?
To meet up with Mr. Tofu?

Mr. Tofu “met his match” at the LA Tofu Festival. Why did Tofurky cross the road?
To go to the dork side!


This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Spring 2013.

Kaayla T. Daniel, PhD, CCN, is The Naughty NutritionistTM because of her ability to outrageously and humorously debunk nutritional myths. A popular guest on radio and television, she has appeared on The Dr. Oz Show, ABC's View from the Bay, NPR's People's Pharmacy and numerous other shows. Her own radio show, "Naughty Nutrition with Dr. Kaayla Daniel," launches April 2011 on World of Women Radio. Dr. Daniel is the author of The Whole Soy Story: The Dark Side of America's Favorite Health Food, a popular speaker at Wise Traditions and other conferences, and recipient of its 2005 Integrity in Science Award. Her website is and she can be reached at

One Response to Soy and Seizures: Bad News for the Soy Industry

  1. Steven Hurdle says:

    This article is neither scientific nor journalistic. This article raises concerns about modern day prisoners in Illinois despite acknowledging that the number of seizures occurring among them today is unknown, that the amount of soy consumed by prisoners in the 1970s is unknown, and that there are many other possible reasons for the seizures the prisoners were experiencing. In other words, it’s based upon theory and supposition.

    I used to be a huge opponent of anti-unfermented soy, and advocated that people not consume it in any quantity. I avoided it personally. I did this based on theory. But one thing I’ve learned is that theory is useless until you put it to the test. Put it to the test, and the concerns about soy fall apart. Yet, the health benefits of soy stand up. Some of the longest living populations ever studied in the world (the adventist population in California, various groups in Japan) have high soy consumption. And they were not only the longest living, but some of the healthiest and most vibrant.

    A good example of this is people who raise concerns about the phyto-estrogens in soy. But many of these anti-soy crusaders (myself included at one time) didn’t raise the alarm bells about the *actual* estrogens present in cows milk, since cows in factory farms are pregnant 10 out of 12 months of the year, and are milked while they’re pregnant.

    Concerns about avoiding soy as a meat replacement are misplaced as regards neurological diseases such as Alzheimer’s. The preponderance of evidence now suggests that cholesterol plaque (which only comes from animal products) building up in the brain is what causes a raft of “unexplained” neurological diseases. If it’s proven to be true that soy worsens the condition once caused, it appears that the condition itself can be avoided entirely by eliminating animal products from one’s diet, so soy is still a benefit to the degree that it helps someone eliminate animal products from one’s diet.

    “What to do in the meantime? Those smart enough to value their brain health will say “better safe than sorry” and cut way back on soy!”

    This advice would be much better put towards animal products in general as consumption of animal agricultural products is strongly correlated with heart disease, diabetes, alzheimer’s, ADD, ADHD, autism, parkinson’s, multiple sclerosis, and more.

    Ending the article with jokes about soy? Again, hardly journalistic.

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