Imagine a world where:
- diabetes, heart diseases, autoimmunity and other modern diseases are rare or don’t exist at all
- we are naturally lean and fit
- we are fertile throughout our childbearing years
- we sleep peacefully and deeply
- we age gracefully without degenerative diseases like Alzheimer’s and osteoporosis
While this might sound like pure fantasy today, anthropological evidence suggests that this is exactly how human beings lived for the vast majority of our evolutionary history.
Today, most people accept diseases like obesity, diabetes, infertility and Alzheimer’s as “normal”. But while these diseases may now be common, they’re anything but normal. Humans evolved roughly 2.5 million years ago, and for roughly 84,000 generations we were naturally free of the modern diseases which kill millions of people each year and make countless others miserable. In fact, the world I asked you to imagine above – which may seem preposterous and unattainable today – was the natural human state for our entire history on this planet up until a couple hundred years ago.
What was responsible for the change? What transformed us from naturally healthy and vital people free of degenerative disease into a world of sick, fat, infertile and unhappy people?
In a word? The modern lifestyle. And though there are several aspects of our current lifestyle that contribute to disease, the widespread consumption of food toxins is by far the greatest offender. Specifically, the following four dietary toxins are to blame:
- Cereal grains (especially refined flour)
- Omega-6 industrial seed oils (corn, cottonseed, safflower, soybean, etc.)
- Sugar (especially high-fructose corn syrup)
- Processed soy (soy milk, soy protein, soy flour, etc.)
What is a toxin?
At the simplest level, a toxin is something capable of causing disease or damaging tissue when it enters the body. When most people hear the word “toxin”, they think of chemicals like pesticides, heavy metals or other industrial pollutants. But even beneficial nutrients like water, which are necessary to sustain life, are toxic at high doses.
In their book The Perfect Health Diet, Paul & Shou-Ching Jaminet apply the economic principle of declining marginal benefits to toxins:
It implies that the first bit eaten of any toxin has low toxicity. Each additional bit is slightly more toxic than the bit before. At higher doses, the toxicity of each bit continues to increase, so that the toxin is increasingly poisonous.
This is important to understand as we discuss the role of dietary toxins in contributing to modern disease. Most of us won’t get sick from eating a small amount of sugar, cereal grain, soy and industrial seed oil. But if we eat those nutrients (or rather anti-nutrients) in excessive quantities, our risk of developing modern diseases rises significantly.
That’s exactly what’s happening today. These four food toxins – refined cereal grains, industrial seed oils, sugar and processed soy – comprise the bulk of the modern diet. Bread, pastries, muffins, crackers, cookies, soda, fruit juice, fast food and other convenience foods are all loaded with these toxins. And when the majority of what most people eat on a daily basis is toxic, it’s not hard to understand why our health is failing.
Let’s look at each of these food toxins in more detail.
Cereal grains: the unhealthiest “health food” on the planet?
The major cereal grains – wheat, corn, rice, barley, sorghum, oats, rye and millet – have become the staple crops of the modern human diet. They’ve also become the “poster children” of the low-fat, high-carbohydrate diet promoted by organizations like the American Heart Association (AHA) and American Diabetes Association (ADA). If you say the phrase “whole grains” to most people, the first word that probably comes to their mind is “healthy”.
But the fact is that most animals, including our closest relative (the chimpanzee) aren’t adapted to eating cereal grains and don’t eat them in large quantities. And humans have only been eating them for the past 10,000 years (a tiny blip of time on the scale of evolution). Why?
Because plants like cereal grains are always competing against predators (like us) for survival. Unlike animals, plants can’t run away from us when we decide to eat them. They had to evolve other mechanisms for protecting themselves. These include:
- producing toxins that damage the lining of the gut;
- producing toxins that bind essential minerals, making them unavailable to the body; and,
- producing toxins that inhibit digestion and absorption of other essential nutrients, including protein.
One of these toxic compounds is the protein gluten, which is present in wheat and many of the other most commonly eaten cereal grains. In short, gluten damages the intestine and makes it leaky. And researchers now believe that a leaky gut is one of the major predisposing factors for conditions like obesity, diabetes and autoimmune disease.
Celiac disease (CD) – a condition of severe gluten intolerance – has been well known for decades. Celiacs have a dramatic and, in some cases, potentially fatal immune response to even the smallest amounts of gluten.
But celiac disease is just the tip of the iceberg when it comes to intolerance to wheat and other gluten containing grains. Celiac disease is characterized by antibodies to two components of the gluten compound: alpha-gliadin, and transglutaminase. But we now know that people can and do react to several other components of wheat and gluten. The diagram below shows how wheat and gluten are broken down in the body:
Current laboratory testing for gluten intolerance only tests for alpha-gliadin and transglutaminase, the two components of gluten implicated in celiac disease (highlighted in red in the diagram). But as you can see, wheat contains several other components including lectins like wheat germ agglutinin (WGA), other epitopes of the gliadin protein like beta-gliadin, gamma-gliadin and omega-gliadin, another protein called glutenin, an opioid peptide called gluteomorphin, and a compound called deamidated gliadin produced by the industrial processing or digestion of gluten.
So here’s the thing. Studies now clearly show that people can react negatively to all of these components of wheat – not just the alpha-gliadin and transglutaminase that celiacs react to. And the worst part of this is that up until about 2 weeks ago, no commercial labs were testing for sensitivity to these other subfractions of wheat.
This means, of course, that it’s extremely likely that far more people are intolerant to wheat and gluten than conventional wisdom would tell us. In fact, that’s exactly what the latest research shows. Dr. Kenneth Fine, a pioneer in gluten intolerance research, has demonstrated that 1 in 3 Americans are gluten intolerant, and that 8 in 10 have the genes that predispose them to developing gluten intolerance.
This is nothing short of a public health catastrophe in a nation where the #1 source of calories is refined flour. But while most are at least aware of the dangers of sugar, trans-fat and other unhealthy foods, fewer than 1 in 8 people with celiac disease are aware of their condition. A 1999 paper in the British Medical Journal illustrated this well:
Patients with clinically obvious celiac disease (observable inflammation and destruction of the gut tissue) comprise only 12.5% of the total population of people with CD. 87.5% of those with celiac have no obvious gut symptoms. For every symptomatic patient with CD, there are 8 patients with CD and no gastrointestinal symptoms.
But does that mean patients with CD without gut symptoms are healthy? Not at all. It was long believed that the pathological manifestations of CD were limited to the gastrointestinal tract. But research over the past few decades has revealed that gluten intolerance can affect almost every other tissue and system in the body, including:
- endocrine system;
- stomach and liver;
- nucleus of cells;
- blood vessels; and,
- smooth muscle,
just to name a few!
This explains why CD and gluten intolerance are associated with several different diseases, including type 1 diabetes, thyroid disorders, osteoporosis, neurodegenerative conditions like Alzheimer’s, Parkinson’s and dementia, psychiatric illness, ADHD, rheumatoid arthritis, migraine, obesity and more. The table below from thesame 1999 BMJ paper depicts the increased incidence of other diseases in patients with CD:
As you can see, up to 17% of people with CD have an “undefined neurological disorder”. But even that alarmingly high statistic only accounts for people with diagnosed CD. We know that only 1 in 8 people with CD are diagnosed. We also know that those with CD represent only a small fraction of the population of people with gluten intolerance. With this in mind, it’s not hard to imagine that the number of people with gluten intolerance that have “undefined neurological disorders” (and other associated conditions on the list above) could be significantly higher than current research suggests.
Finally, we also now know that when you are gluten intolerant – which 33% (if not more) of you are – you will also “cross-react” with other foods that have a similar “molecular signature” to gluten and its components. Unfortunately, the list of these foods (shown below) contains all grains, which is why some medical practitioners (myself included) recommend not just a gluten-free diet, but an entirely grain-free diet. As you can see, it also contains other foods like dairy (alpha & beta casein, casomorphin, milk butyrophilin) and coffee (which is a very common cross-reactant).
- milk butyrophilin
- cow’s milk
- american cheese
- all cereal grains
Industrial seed oils: unnatural and unfit for human consumption
Industrial seed oils (corn, cottonseed, soybean, safflower, sunflower, etc.) have not been a part of the human diet up until relatively recently, when misguided groups like the AHA and the ADA started promoting them as “heart-healthy” alternatives to saturated fat.
The graph below shows how dramatically seed oil consumption has risen over the past several decades:
Throughout 4-5 million years of hominid evolution, diets were abundant in seafood and other sources of omega-3 long chain fatty acids (EPA & DHA), but relatively low in omega-6 seed oils.
Anthropological research suggests that our hunter-gatherer ancestors consumed omega-6 and omega-3 fats in a ratio of roughly 1:1. It alsoindicates that both ancient and modern hunter-gatherers were free of the modern inflammatory diseases, like heart disease, cancer, and diabetes, that are the primary causes of death and morbidity today.
At the onset of the industrial revolution (about 140 years ago), there was a marked shift in the ratio of n-6 to n-3 fatty acids in the diet. Consumption of n-6 fats increased at the expense of n-3 fats. This change was due to both the advent of the modern vegetable oil industry and the increased use of cereal grains as feed for domestic livestock (which in turn altered the fatty acid profile of meat that humans consumed).
The following chart lists the omega-6 and omega-3 content of various vegetable oils and foods:
Vegetable oil consumption rose dramatically between the beginning and end of the 20th century, and this had an entirely predictable effect on the ratio of omega-6 to omega-3 fats in the American diet. Between 1935 and 1939, the ratio of n-6 to n-3 fatty acids was reported to be 8.4:1. From 1935 to 1985, this ratio increased to 10.3:1 (a 23% increase). Other calculations put the ratio as high as 12.4:1 in 1985. Today, estimates of the ratio range from an average of 10:1 to 20:1, with a ratio as high as 25:1 in some individuals.
In fact, Americans now get almost 20% of their calories from a single food source – soybean oil – with almost 9% of all calories from the omega-6 fat linoleic acid (LA) alone! (PDF)
This reveals that our average intake of n-6 fatty acids is between 10 and 25 times higher than evolutionary norms. The consequences of this dramatic shift cannot be underestimated.
So what are the consequences to human health of an n-6:n-3 ratio that is up to 25 times higher than it should be?
The short answer is that elevated n-6 intakes are associated with an increase in all inflammatory diseases – which is to say virtually all diseases. The list includes (but isn’t limited to):
- cardiovascular disease
- type 2 diabetes
- metabolic syndrome
- irritable bowel syndrome & inflammatory bowel disease
- macular degeneration
- rheumatoid arthritis
- psychiatric disorders
- autoimmune diseases
The relationship between intake n-6 fats and cardiovascular mortality is particularly striking. The following chart, from an article entitled Eicosanoids and Ischemic Heart Disease by Stephan Guyenet, clearly illustrates the correlation between a rising intake of n-6 and increased mortality from heart disease:
As you can see, the USA is right up there at the top with the highest intake of n-6 fat and the greatest risk of death from heart disease.
On the other hand, several clinical studies have shown that decreasing the n-6:n-3 ratio protects against chronic, degenerative diseases. One study showed that replacing corn oil with olive oil and canola oil to reach an n-6:n-3 ratio of 4:1 led to a 70% decrease in total mortality. That is no small difference.
Joseph Hibbeln, a researcher at the National Institute of Health (NIH) who has published several papers on n-3 and n-6 intakes, didn’t mince words when he commented on the rising intake of n-6 in a recent paper:
The increases in world LA consumption over the past century may be considered a very large uncontrolled experiment that may have contributed to increased societal burdens of aggression, depression and cardiovascular mortality.
And those are just the conditions we have the strongest evidence for. It’s likely that the increase in n-6 consumption has played an equally significant role in the rise of nearly every inflammatory disease. Since it is now known that inflammation is involved in nearly all diseases, including obesity and metabolic syndrome, it’s hard to overstate the negative effects of too much omega-6 fat.
Sugar: the sweetest way to wreck your health
About 20 years ago, Nancy Appleton, PhD, began researching all of the ways in which sugar destroys our health. Over the years the list has continuously expanded, and now includes 141 points. Here’s just a small sampling (the entire list can be found on her blog).
- Sugar feeds cancer cells and has been connected with the development of cancer of the breast, ovaries, prostate, rectum, pancreas, lung, gallbladder and stomach.
- Sugar can increase fasting levels of glucose and can cause reactive hypoglycemia.
- Sugar can cause many problems with the gastrointestinal tract, including an acidic digestive tract, indigestion, malabsorption in patients with functional bowel disease, increased risk of Crohn’s disease and ulcerative colitis.
- Sugar can interfere with your absorption of protein.
- Sugar can cause food allergies.
- Sugar contributes to obesity.
But not all sugar is created alike. White table sugar (sucrose) is composed of two sugars: glucose and fructose. Glucose is an important nutrient in our bodies and is healthy, as long as it’s consumed in moderation. Fructose is a different story.
Fructose is found primarily in fruits and vegetables, and sweeteners like sugar and high-fructose corn syrup (HFCS). A recent USDA report found that the average American eats 152 pounds of sugar each year, including almost 64 pounds of HFCS.
Unlike glucose, which is rapidly absorbed into the bloodstream and taken up by the cells, fructose is shunted directly to the liver where it is converted to fat. Excess fructose consumption causes a condition called non-alcoholic fatty liver disease (NAFLD), which is directly linked to both diabetes and obesity.
A 2009 study showed that shifting 25% of dietary calories from glucose to fructose caused a 4-fold increase in abdominal fat. Abdominal fat is an independent predictor of insulin sensitivity, impaired glucose tolerance, high blood pressure, high cholesterol, high triglycerides and several other metabolic diseases.
In a widely popular talk on YouTube, Dr. Robert H. Lustig explains that fructose has all of the qualities of apoison. It causes damage, provides no benefit and is sent directly to the liver to be detoxified so that it doesn’t harm the body.
Soy: another toxin promoted as a health food
Like cereal grains, soy is another toxin often promoted as a health food. It’s now ubiquitous in the modern diet, present in just about every packaged and processed food in the form of soy protein isolate, soy flour, soy lecithin and soybean oil.
For this reason, most people are unaware of how much soy they consume. You don’t have to be a tofu-loving hippie to eat a lot of soy. In fact, the average American – who is most definitely not a tofu-loving hippie – gets up to 9% of total calories from soybean oil alone.
Whenever I mention the dangers of soy in my public talks, someone always protests that soy can’t be unhealthy because it’s been consumed safely in Asia for thousands of years. There are several reasons why this isn’t a valid argument.
First, the soy products consumed traditionally in Asia were typically fermented and unprocessed – including tempeh, miso, natto and tamari. This is important because the fermentation process partially neutralizes the toxins in soybeans.
Second, Asians consumed soy foods as a condiment, not as a replacement for animal foods. The average consumption of soy foods in China is 10 grams (about 2 teaspoons) per day and is 30 to 60 grams in Japan. These are not large amounts of soy.
Contrast this with the U.S. and other western countries, where almost all of the soy consumed is highly processed and unfermented, and eaten in much larger amounts than in Asia.
How does soy impact our health? The following is just a partial list:
- Soy contains trypsin inhibitors that inhibit protein digestion and affect pancreatic function;
- Soy contains phytic acid, which reduces absorption of minerals like calcium, magnesium, copper, iron and zinc;
- Soy increases our requirement for vitamin D, which 50% of American are already deficient in;
- Soy phytoestrogens disrupt endocrine function and have the potential to cause infertility and to promote breast cancer in adult women.
- Vitamin B12 analogs in soy are not absorbed and actually increase the body’s requirement for B12;
- Processing of soy protein results in the formation of toxic lysinoalanine and highly carcinogenic nitrosamines;
- Free glutamic acid or MSG, a potent neurotoxin, is formed during soy food processing and additional amounts are added to many soy foods to mask soy’s unpleasant taste; and,
- Soy can stimulate the growth of estrogen-dependent tumors and cause thyroid problems, especially in women.
Perhaps most alarmingly, a study at the Harvard Public School of Health in 2008 found that men who consumed the equivalent of one cup of soy milk per day had a 50% lower sperm count than men who didn’t eat soy.
In 1992, the Swiss Health Service estimated that women consuming the equivalent of two cups of soy milk per day provides the estrogenic equivalent of one birth control pill. That means women eating cereal with soy milk and drinking a soy latte each day are effectively getting the same estrogen effect as if they were taking a birth control pill.
This effect is even more dramatic in infants fed soy formula. Babies fed soy-based formula have 13,000 to 22,000 times more estrogen compounds in their blood than babies fed milk-based formula. Infants exclusively fed soy formula receive the estrogenic equivalent (based on body weight) of at least five birth control pills per day.
See below a complete list of studies demonstrating the harmful effects of soy products. Source of web
|Studies Showing Adverse Effects of Dietary Soy, 1939-2008|
|August 26 2003|
|Additional Studies: For a list of studies showing the toxicity of soy in the US Food & Drug Administration’s Poisonous Plant Database, see FDA Soy References. Also seehttp://toxicstudylist.blogspot.com and http://fetaltoxic.blogspot.com.Dietary Soy Study Summaries1939
Sharpless GR and others. Production of goiter in rats with raw and with treated soybean flour. J Nutr 17 (Jun), 545-55. Unprocessed soybean flour, when fed as part of a diet over seven weeks to rats, makes the thyroid grow to four times its usual size. In addition the amount of iodine required by a rat on this diet is twice the normal amount.1941
Wilgus HS and others. The goitrogenicity of soybeans. J Nutr, 22, 43-52. The study found that soybeans are disruptive to the proper functioning of thyroids causing goiters in chicks. When the consumption of soybean oil meal increased from 30% to 60% of their diet, the goiters doubled in size.
Almquist HJ and Merrit JB. Effect of Soybean Antitrypsin on Growth of the Chick. Arch Biochem, 35, 352-4. Raw soybean meal in amounts as small as 5% of daily protein intake in chicks was responsible for close to “maximal growth retardation.”
Pritchard WR and others. Aplastic Anemia of Cattle Associated with Ingestion of Trichloroethylene-Extracted Soybean Oil Meal (Stockman Disease, Duren Disease, Brabant Disease). J Am Vet Med Assoc. 1952 Jul;121(904):1-8. The study was conducted across 44 herds (a total of 1776 cattle), using varying amounts trichloroethylene-extracted soybean oil meal as feed. In most cases calves under six months who were fed 1-3 lbs per day were the first to die from Aplastic anemia. In some cases they died in under fives weeks of consumption. Lacatation females also experienced a mortality rate that was considerably higher. Adults 24 months and older who ate between 1-4 lbs of the feed per day experienced an average 21% death rate.
Liener IE. Soyin, a toxic protein from the soybean. I. Inhibition of rat growth. J Nutr, 49, 527-39. Soyin, in levels intended to simulate unheated soy flour, after being fed to rats was found to possibly cause “an enforced limitation of food intake with a consequent impairment of growth.”
Eveleth DF and others. Toxicosis of chickens caused by trichloroethylene-extracted soybean meal. J Am Vet Med Assoc, 123, 38-9. During the fifty day period the death rate of birds fed the soybean meal was 26.3%, the death rate of the control group was 4.8%. Of the remaining birds after the 50 day period the average weight of the control group was 1.12 lbs while the weight for those fed the soybean meal was .78 lbs.
Shepard T. Feeding of Soybean and Development of Goiter. Pediatrics 1959;24;854. The author took three cases of goiters in children in which the “thyroid enlargement (was) apparently related to intake of a soybean milk.” Two of the three children were switched to solid food and cows milk and their goiters grew smaller.
Van Wyck JJ and other. The Effects Of A Soybean Product On Thyroid Function In Humans. Pediatrics, 24, 752-60. The study analyzes the effects of soy infant formula, showing that goiters and hypothyroidism are known to occur after consumption. The hindrance of thyroid hormone synthesis cause people to have to increase their intake of iodine. In the case of one child the hypothyroidism was cured by drinking whole cows milk instead of the soy.
Gorill ADL and others. Exocrine pancreatic secretions by calves fed soybean and milk diet proteins. J Nutr, 92(1), 256. Calves fed the milk protein gained an average of 78 grams of weight per day while the calves fed the soy lost an average of 75 grams of weight per day. Those consuming soy protein also experienced a reduced flow rate and reduced levels of protein, trypsin and chemotrypsin in their pancreatic juice. “The soybean flour used in this experiment exerted a marked depression on exocrine pancreatic function of calves, which was detected after the animals had received the high soy diet for 2-5 days.”
Jensen L and others. A Foot Pad Dermatitis in Turkey Poults Associated with Soybean Meal. Poultry Sci, 49, 76-82. There was a frequents occurrence of foot pad dermatis in Turkeys fed soybean meal poults, whereas the occurrence was rare in turkeys fed a diet containing casein, gelatin and corn.
Wallace, GM. Studies on the Processing and Properties of Soymilk. J Sci Food Agri 1971 Oct;22:526-535. In order to neutralize the protease inhibitors (enzymes that inhibit the digestion of protein) in soy, it must be heated to very high temperatures under pressure and for considerable time. This process unfortunately denatures the overall protein content of soy, rendering it largely ineffective.
Joseph, JR. Biological and physiological Factors in Soybeans. JOACS, 1974 Jan;51:161A-170A. In feeding experiments, use of soy protein isolate (SPI) increased requirements for vitamins E, K, D and B12 and created deficiency symptoms of calcium, magnesium, manganese, molybdenum, copper, iron and zinc.
Nutrition during Pregnancy and Lactation. California Department of Health, 1975. Soy is listed as a minor source of protein in Japanese and Chinese diets. Major sources of protein listed were meat including organ meats, poultry, fish and eggs.
Searle CE, ed, Chemical Carcinogens, ACS Monograph 173, American Chemical Society, Washington, DC, 1976. Asians throughout the world have high rates of thyroid cancer.
Chang KC, ed, Food in Chinese Culture: Anthropological and Historical Perspectives, New Haven, 1977. This survey found that soy foods accounted for only 1.5 percent of calories in the Chinese diet, compared with 65 percent of calories from pork.
FDA ref 72/104, Report FDABF GRAS – 258. In 1972, the Nixon administration directed a reexamination of substances believed to be GRAS in the light of any scientific information then available. This reexamination included casein protein which became codified as GRAS in 1978. In 1974, the FDA obtained a literature review of soy protein because, as soy protein had not been used in food until 1959 and was not even in common use in the early 1970s, it was not eligible to have its GRAS status grandfathered under the provisions of the Food, Drug and Cosmetic Act.
Evaluation of the Health Aspects of Soy Protein Isolates as Food Ingredients. Prepared for FDA by Life Sciences Research Office, Federation of American Societies for Experimental Biology, 9650 Rockville Pike, Bethesda, MD 20014, Contract No, FDA 223-75-2004, 1979. In this document, the FDA expresses concern about nitrites and lysinoalanine in processed soy. Even at low levels of consumption–averaging one-third of a gram per day at the time–the presence of these carcinogens was considered too great a threat to public health to allow GRAS status. Soy protein did have approval for use as a binder in cardboard boxes and this approval was allowed to continue because researchers considered that migration of nitrites from the box into the food contents would be too small to constitute a cancer risk. FDA officials called for safety specifications and monitoring procedures before granting of GRAS status for food. These were never performed. To this day, use of soy protein is codified as GRAS only for limited industrial use as a cardboard binder.
Torum, B. Nutritional Quality of Soybean Protein Isolates: Studies in Children of Preschool Age. Soy Protein and Human Nutrition, Harold L Wilcke and others, eds, Academic Press, New York, 1979. A group of Central American children suffering from malnutrition was first stabilized and brought into better health by feeding them native foods, including meat and dairy products. Then for a two-week period these traditional foods were replaced by a drink made of soy protein isolate and sugar. All nitrogen taken in and all nitrogen excreted were measured. The researchers found that the children retained nitrogen and that their growth was “adequate,” so the experiment was declared a success. However, the researchers noted that the children vomited “occasionally,” usually after finishing a meal; over half suffered from periods of moderate diarrhea; some had upper respiratory infections; and others suffered from rash and fever. It should be noted that the researchers did not dare to use soy products to help children recover from malnutrition, and were obliged to supplement the soy? sugar mixture with nutrients largely absent in soy products, notably vitamins A, D, B12, iron, iodine and zinc.
Casey CE and others. Availability of zinc: loading tests with human milk, cow’s milk, and infant formulas.Pediatrics 1981;68(3):394-6. Female subjects consumed 25 mg of zinc with milk or formula, the amount of which was calculated to provide 5 gm of protein, after an eight-hour fast. Blood samples were taken prior to (base line) and at 30-minute intervals for three hours after consumption of zinc. The plasma response with human milk was significantly greater than with cow’s milk and all the formulas. The response with cow’s milk and a cow’s milk-based formula was one third that with human milk; responses with a soy-based and two casein hydrolysate-based formulas were even lower.
Lebenthal E and others. The development of pancreatic function in premature infants after milk-based and soy-based formulas. Pediatr Res 1981 Sep;15(9):1240-1244. Soy formula fed to premature babies caused in increase in digestive enzymes compared to milk-fed babies, indicating low digestibility of soy formula.
Murphy PA. Phytoestrogen Content of Processed Soybean Foods. Food Technology. 1982:50-54. One hundred grams of soy protein, the maximum suggested cholesterol-lowering dose in the FDA-sanctioned health claim, can contain almost 600 mg of isoflavones.
Wenk GL and Stemmer KL. Suboptimal dietary zinc intake increases aluminum accumulation into the rat brain.Brain Res 1983;288:393-395. Zinc deficiency will cause more aluminum to be absorbed into the body in general, and into the brain in particular. Aluminum will be absorbed by competing for binding sites on a zinc-containing ligand. Fluoride and phytates in soy formula will induce zinc deficiency.
Poley JR and Klein AW. Scanning electron microscopy of soy protein-induced damage of small bowel mucosa in infants. J Pediatr Gastroenterol Nutr 1983 May;2(2):271-87. Soy feeding caused damage to small bowel mucosa in 2 infants. The damage was similar to that of celiac disease and consistent with a lectin-induced toxicity.
Tait S and others. The availability of minerals in food, with particular reference to iron. Journal of Research in Society and Health, April 1983;103(2):74?77. When precipitated soy products like tofu are consumed with meat, the mineral blocking effects of the phytates are reduced. The Japanese traditionally eat a small amount of tofu or miso as part of a mineral rich fish broth, followed by a serving of meat or fish.
Ross RK. Effect of in-utero exposure to diethylstilbesterol on age at onset of puberty and on post-pubertal hormone levels in boys,” Canadian Medical Association Journal 1983, May 15;128(10):1197-8. Male children exposed during gestation to diethylstilbesterol (DES), a synthetic estrogen that has effects on animals similar to those of phytoestrogens from soy, had testes smaller than normal on maturation.
Ologhobo AD and others. Distribution of phosphorus and phytate in some Nigerian varieties of legumes and some effects of processing. Journal of Food Science. January/February 1984;49(1):199-201. The phytic acid in soy is highly resistant to normal phytate-reducing techniques, such as soaking or long, slow cooking.
Rackis JJ and others. The USDA trypsin inhibitor study. I. Background, objectives and procedural details.Qualification of Plant Foods in Human Nutrition, 1985;35. Diets of soy protein isolate high in trypsin inhibitors caused depressed growth and enlargement and pathological conditions of the pancreas, including cancer, and enlarged thryoid glands in rats. Analyses for this study showed that trypsin inhibitor content of soy protein isolate can vary as much as fivefold. Even low-level-trypsin-inhibitor SPI feeding resulted in reduced weight gain compared to controls. Soy protein isolate and textured vegetable protein made from soy protein isolate are used extensively in school lunch programs, imitation foods, commercial baked goods, diet beverages, meal replacements and fast food products. They are heavily promoted in Third World countries and form the basis of many food giveaway programs.
McGraw MD and others. Aluminum content in milk formulae and intravenous fluids used in infants. Lancet I:157 (1986). Carefully collected human breast milk contained 5 to 20 micrograms aluminum per liter; concentrations were 10 to 20 fold greater in most cow’s milk-based formulas and 100-fold greater in soy-based formulas.
Fort P and others. Breast feeding and insulin-dependent diabetes mellitus in children. J Am Coll Nutr1986;5(5):439-441. Twice as many soy-fed children developed diabetes as those in a control group that was breastfed or received milk-based formula. It was based on this study that the American Academy of Pediatrics took a position of opposition to the use of soy infant formula. This objection was later dropped after the AAP received substantial grants from the Infant Formula Council.
Freni-Titulaer LW and others. Am J Dis Child 1986 Dec;140(12):1263-1267.Soy infant feeding was associated with higher rates of early development in girls, including breast development and pubic hair before the age of eights, sometimes before the age of three.
Tudor RJ and others. Comparative Subacute Effects Of Dietary Raw Soya Flour On The Pancreas Of Three Species, The Marmoset, Mouse and Rat. Food Chem Toxic. 25 (10), 739-45. Ingestion of soy produced enlarged pancreases in mice and “pancreatic adenoma and carcinoma in the rat.”
Dabeka RW and McKenzie AD. Lead, cadmium, and fluoride levels in market milk and infant formulas in Canada. J Assoc Off Anal Chem 1987;70(4):754-7 (1987). Soy based or milk-free formulas contained about 8-15 times more cadmium than milk-based formulas as well as high amounts of fluoride.
Katz SH. Food and Biocultural Evolution: A Model for the Investigation of Modern Nutritional Problems.Nutritional Anthropology, Alan R. Liss Inc., 1987, p 50. During the Chou Dynasty (1134 – 246 BC) the soybean was designated one of the five sacred grains, along with barley, wheat, millet and rice. However, the pictograph for the soybean, which dates from earlier times, indicates that it was not first used as a food; for whereas the pictographs for the other four grains show the seed and stem structure of the plant, the pictograph for the soybean emphasizes the root structure. Agricultural literature of the period speaks frequently of the soybean and its use in crop rotation. Apparently the soy plant was initially used as a method of fixing nitrogen. The soybean did not serve as a food until the discovery of fermentation techniques, sometime during the Chou Dynasty. Katz speculates that the rise of liver cancer in Africa is caused by the introduction of soy foods into the African diet.
El Tiney A. Proximate Composition and Mineral and Phytate Contents of Legumes Grown in Sudan. Journal of Food Composition and Analysis 1989;2:67-68. Soybeans are listed as having some of the highest levels of phytic acid of all legumes. Phytic acid blocks the absorption of zinc, iron, copper and magnesium.
Campbell TC. The Cornell-China-Oxford Project on Nutrition, Health and Environment. 1990; Chen J and others. Diet, Lifestyle and Mortality in China. A study of the characteristics of 65 counties. Monograph, joint publication of Oxford University Press, Cornell University Press, China People’s Medical Publishing House. 1990. This exhaustive study of Chinese diets found that legume consumption ranged from 0 to 58 grams per day, with an average of 13 grams. Assuming that two-thirds of this is from soybeans, then consumption averages about 9 grams of soy products per day. Isoflavone content would probably be about 10 mg/day.
Fort P and others. Breast and soy-formula feedings in early infancy and the prevalence of autoimmune thyroid disease in children. J Am Coll Nutr 1990;9:164-167. This study documents the association of soy formula feeding in infancy with autoimmune thyroid problems.
Dabeka RW and McKenzie AD. Aluminium levels in Canadian infant formulate and estimation of aluminium intakes from formulae by infants 0-3 months old. Food Addit Contam 1990;7(2):275-82. Researchers found that aluminum content in soy formula for 1-3 month old infants could result in an intake of 363 micrograms/kg/day (2088 micrograms/day) alone, not including potential contribution from other foods or water.
Hagger C and Bachevalier J. Visual habit formation in 3-month-old monkeys (Macaca mulatta): reversal of sex difference following neonatal manipulations of androgen. Behavior and Brain Research 1991, 45:57-63. Male infants undergo a “testosterone surge” during the first few months of life, when testosterone levels may be as high as those of an adult male. During this period, the infant is programmed to express male characteristics after puberty, not only in the development of his sexual organs and other masculine physical traits, but also in setting patterns in the brain characteristic of male behavior. In monkeys, deficiency of male hormones impairs the development of spatial perception (which, in humans, is normally more acute in men than in women), of learning ability and of visual discrimination tasks (such as would be required for reading.)
Grant G and others. Pancreatic enlargement is evident in rats fed diets containing raw soybeans (Glycine max) or cowpeas (Vigna unguiculata) for 800 days but not in those fed diets based on kidney beans (Phaseolus vulgaris) or lupin seed (Lupinus angustifolius). J Nutr, 123(12), 2207-15. During the initial 150 days of the study, rats fed the soybean diet experienced abnormal levels pancreatic growth. Some of the rats fed the soybean diet also experienced the growth of nodules on the pancreas after 500 days.
Messina MJ and others. Soy Intake and Cancer Risk: A Review of the In Vitro and In Vivo Data,” Nutrition and Cancer, 1994, 21:(2):113-131. This study fueled speculation on soy’s anti-carcinogenic properties. The authors noted that in 26 animal studies, 65 percent reported protective effects from soy. At least one study was left out, in which soy feeding caused pancreatic cancer, the 1985 study by Rackis. In the human studies listed, the results were mixed. A few showed some protective effect but most showed no correlation at all between soy consumption and cancer rates. “. . the data in this review cannot be used as a basis for claiming that soy intake decreases cancer risk.” In a subsequent book, The Simple Soybean and Your Health, Messina recommends 1 cup or 230 grams of soy products per day in his “optimal” diet as a way to prevent cancer.
Hawkins NM and others. Potential aluminium toxicity in infants fed special infant formula. J Pediatr Gastroenterol Nutr 1994;19(4):377-81 (1994). Researchers found aluminum concentrations of 534 micrograms/L in soy formula, as compared to 9.2 micrograms/L in breast milk. The authors concluded that infants might be at risk from aluminium toxicity when consuming formula containing more than 300 micrograms/L.
Chorazy PA and others. Persistent hypothyroidism in an infant receiving a soy formula: case report and review of the literature. Pediatrics 1995 Jul;96(1 Pt 1):148-50. The study describes a case of persistent hypothyroidism in an infant who had received soy formula.
Anderson JW and others. Meta-analysis of the Effects of Soy Protein Intake on Serum Lipids. New England Journal of Medicine, 1995 333:(5):276-82. The FDA’s allowance of a health claim for soy protein is based largely on this meta-analysis, sponsored by Protein Technologies International. However, the study authors discarded eight studies for various reasons, leaving a remainder of 29. The published report suggested that individuals with cholesterol levels over 250 mg/dl would experience a “significant” reduction of 7 to 20 percent in levels of serum cholesterol if they substituted soy protein for animal protein. Cholesterol reduction was insignificant for individuals whose cholesterol was lower than 250 mg/dl. In other words, for most of the population, the substitution of meat with soy will not bring blood cholesterol levels down.
Harras A, ed. Cancer Rates and Risks, 4th Edition, 1996, National Institutes of Health, National Cancer Institute. This report shows that the Japanese, and Asians in general, have lower rates of breast and prostate cancer but much higher rates of other types of cancer, particularly cancer of the esophagus, stomach, pancreas and liver.
Fukutake M and others. Quantification of genistein and genistin in soybeans and soybean products. Food Chem Toxicol 1996;34:457-461. Average Isoflavones consumption in Japan was found to be about 10 mg per day.
IEH assessment on Phytoestrogens in the Human Diet, Final Report to the Ministry of Agriculture, Fisheries and Food, UK, November 1997. This exhaustive report on phytoestrogens, prepared by the British government, failed to find much evidence of benefit and warned against potential adverse effects.
Herman-Giddens ME and others. Secondary Sexual Characteristics and Menses in Young Girls Seen in Office Practice: A Study from the Pediatric Research in Office Settings Network. Pediatrics, 1997 Apr;99:(4):505-512. Investigators found that one percent of all girls now show signs of puberty, such as breast development or pubic hair, before the age of three; by age eight, 14.7 percent of white girls and almost 50 percent of African-American girls had one or both of these characteristics. Our Comment: The widespread use of soy-based formula, beginning in the 1970s, is a likely explanation for the increase in early maturation in girls.
Nagata C and others. Decreased serum total cholesterol concentration is associated with high intake of soy products in Japanese men and women. J Nutr 1998 Feb;128(2):209-13. This study included a survey of soy consumption among Japanese men and women. Consumption of soy products was about 54 grams per day for women and 64 grams per day for men. The total amount of soy protein from these products was 7-8 grams providing about 25 mg Isoflavones.
Irvine CH and others. Phytoestrogens in soy-based infant foods: concentrations, daily intake and possible biological effects. Proc Soc Exp Biol Med 1998 Mar;217(3):247-53. Researchers found that soy formulas provide infants with a daily dose rate of 3 mg/kg body weight total isoflavones, “which is maintained at a fairly constant level between 0-4 months of age. . . . This rate of isoflavone intake is much greater than that shown in adult humans to alter reproductive hormones.”
Yaffe K and others. Serum estrogen levels, cognitive performance, and risk of cognitive decline in older community women. J Am Geriatr Soc 1998 Jul;46(7):918-20. Women in the higher estrone quartiles had lower performance on two cognitive tests.
Irvine CH and others. Daily intake and urinary excretion of genistein and daidzein by infants fed soy- or dairy-based infant formulas. Am J Clin Nutr 1998 Dec;68(6 Suppl):1462S-1465S. Researchers found that “young infants are able to digest, absorb, and excrete genistein and daidzein from soy-based formulas as efficiently as do adults consuming soy products.
Eklund G and Oskarsson A. Exposure of cadmium from infant formulas and weaning foods. Food Addit Contam16(12):509-19 (1999). Cadmium was 6 times higher in soy formulas than cow’s milk formulas.
Olguin MC and others. Intestinal alterations and reduction of growth in prepuberal rats fed with soybean [Article in Spanish]. Medicina (B Aires) 1999;59:747-752. Rats fed soy-based chow had reduced growth and an increase in gastrointestinal problems compared to controls.
Nilhausen K and Meinertz H. Lipoprotein(a) and dietary proteins: casein lowers lipoprotein(a) concentrations as compared with soy protein. Am J Clin Nutr 1999;69:419-25. Many studies have shown that soy consumption can lower serum cholesterol levels. These studies have led to claims that soy can prevent heart disease. However, the theory that high cholesterol levels cause heart disease is becoming more and more untenable. Cholesterol levels are not a good marker for proneness to heart disease. However Lipoprotein(a) or Lp(a), does serve as a good marker for heart disease. This study indicates that soy raises Lp(a), meaning that it is likely to contribute to heart disease.
Food Labeling: Health Claims: Soy Protein and Coronary Heart Disease, Food and Drug Administration 21 CFR Part 101 (Docket No. 98P-0683). This US government document allows a health claim for foods containing 6.25 grams of soy protein per serving. The original petition, submitted by Protein Technologies International (a division of Dupont), requested a health claim for isoflavones, the estrogen-like compounds found plentifully in soybeans, based on assertions that “only soy protein that has been processed in a manner in which isoflavones are retained will result in cholesterol-lowering.” In 1998, the FDA made the unprecedented move of rewriting PTI’s petition, removing any reference to the phytoestrogens and substituting a claim for soy protein, a move that was in direct contradiction to the agency’s regulations. The FDA is authorized to make rulings only on substances presented by petition. The abrupt change in direction was no doubt due to the fact that a number of researchers, including scientists employed by the US government, submitted documents indicating that isoflavones are toxic. The regulations stipulate that 25 grams of soy protein per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. Twenty-five grams soy protein can contain from 24-125 mg isoflavones, depending on processing methods. Many letters were written in protest, expressing concerns about mineral blocking effects, enzyme inhibitors, goitrogenicity, endocrine disruption, reproductive problems and increased allergic reactions from consumption of soy products.
Sheehan DM and Doerge DR, Letter to Dockets Management Branch (HFA-305) February 18, 1999. A strong letter of protest from two government researchers at the National Center for Toxicological Research urging that soy protein carry a warning label rather than a health claim.
Ginsburg J and Prelevic GM. Is there a proven place for phytoestrogens in the menopause?” Climacteric, 1999;2:75-78. Quantification of discomfort from hot flashes is extremely subjective and most studies show that control subjects report reduction in discomfort in amounts equal to subjects given soy.
White L. Association of High Midlife Tofu Consumption with Accelerated Brain Aging. Plenary Session #8: Cognitive Function, The Third International Soy Symposium, Program, November 1999, page 26. An ongoing study of Japanese Americans living in Hawaii found a significant statistical relationship between two or more servings of tofu per week and “accelerated brain aging.” Those participants who consumed tofu in mid life had lower cognitive function in late life and a greater incidence of Alzheimer’s and dementia.
Clarkson TB. Soy phytoestrogens: what will be their role in postmenopausal hormone replacement therapy?Menopause 2000 Mar-Apr;7(2):71-5. Soy did not prevent bone loss when measured at autopsy in female monkeys who had had their reproductive organs removed.
Vincent A and Fitzpatrick LA. Soy isoflavones: are they useful in menopause? Mayo Clin Proc 2000;75:1174-84. “Current data are insufficient to draw definitive conclusions regarding the use of isoflavones as an alternative to estrogen for hormone replacement in postmenopausal women.”
North K and Golding J. A maternal vegetarian diet in pregnancy is associated with hypospadias. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood. BJU Int 2000 Jan;85(1):107-113. Vegetarian women are more likely consume more soy than the general population. Incidence of hypospadias was twice as great in vegetarian mothers than in non-vegetarian mothers. Hypospadias is a birth defect due to interrupted development of the penis.
Nakamura Y and others. Determination of the levels of isoflavonoids in soybeans and soy-derived foods and estimation of isoflavonoids in the Japanese daily intake. J AOAC Int 2000;83:635-650. This survey found that average isoflavone consumption in Japan is about 28 mg per day.
Bee G. Dietary Conjugated Linoleic Acids Alter Adipose Tissue and Milk Lipids of Pregnant and Lactating Sows.J Nutr 2000;130:2292-2298. Dietary mixtures for pigs, which are carefully formulated to promote reproduction and growth, allow approximately 1 percent of the ration as soy in a diet based on grains and supplements. (Pigs have a digestive system similar to humans.) The Central Soya Company, Inc. website gives a range of 2.5 percent to 17.5 percent soy in the diet of pigs, citing a number of anti-nutritional components that “have been documented to cause gastrointestinal disturbance, intestinal damage, increased disease susceptibility and reduced performance in pigs.”
Nagata C. Ecological study of the association between soy product intake and mortality from cancer and heart disease in Japan. International Journal of Epidemiology Oct 2000; 29(5):832-6. This study contained the following official conclusion: “The present study provides modest support for the preventive role of soy against stomach cancer and heart disease death.” However, only the association with lower heart disease death is correct. What the study actually found was that “Soy protein intake was significantly correlated with stomach cancer mortality rate in men” and “soy product intake estimated as total amount as well as isoflavone and soy protein intake were significantly positively correlated with colorectal cancer mortality rates in both sexes.” In other words, men who consumed lots of soy had more stomach cancer and men and women who consumed lots of soy had more colorectal cancer. These results are especially interesting as soy proponents often claim that Asians have lower rates of colorectal cancer because they eat more soy.
Strom BL and others. Exposure to soy-based formula in infancy and endocrinological and reproductive outcomes in young adulthood. JAMA 2001 Nov 21;286(19):2402-3. Although reported in the media as a vindication of soy infant formula, the study actually found that soy-fed infants had more reproductive problems and more asthma as adults.
Massey LK and others. Oxalate content of soybean seeds (Glycine max: Leguminosae), soyfoods, and other edible legumes. J Agric Food Chem 2001 Sep;49(9):4262-6. Soy foods were found to be high in oxalates and likely to contribute to kidney stones.
Khalil DA and others. Soy protein supplementation increases serum insulin-like growth factor-I in young and old men but does not affect markers of bone metabolism. J Nutr 2002 Sep;132(9):2605-8. Men consuming soy protein had higher levels of insulin-like growth factor-I (IGF-I) than those consuming milk protein. According to many other studies (but not stated in the report), high levels of IFG-I are also found in rBGH milk and have been implicated in causing hormonal cancers.
Sun CL and others. Dietary soy and increased risk of bladder cancer: the Singapore Chinese Health Study.Cancer Epidemiol Biomarkers Prev. 2002 Dec;11(12):1674-7. People who consumed 92.5 grams of soy per 1000 Kcal were found to be 2.3 times more likely to be at risk for bladder cancer. The results were calculated to factor in levels of education and cigarette consumption in study participants.
Lack G and others. Factors associates with the development of peanut allergy in childhood. N Engl J Med 2003 Mar 13;348(11):977-85. The number of children with life-threatening peanut allergies has tripled during the last decade. This study suggests a link between consumption of soy-based formula and the development of peanut allergies. Scientists at the University of Bristol monitored 14,000 babies in the southwest of England. Among the 49 children who developed a peanut allergy, almost a quarter had consumed soy milk during their first two years. (Less than 5 percent of babies overall receive soy formula in the UK.) According to lead researcher Gideon Lack, “These results suggest that sensitization to peanut may possibly occur. . . as a result of soya exposure.”
Conrad S and others. Soy formula complicates management of congenital hypothyroidism. Archives of Disease in Childhood 2004 Jan;89(1):37-40. Soy formula was found to increase the level of thyroid stimulating hormones in infants.
Hogervorst E and others. High Tofu Intake Is Associated with Worse Memory in Elderly Indonesian Men and Women. Dementia and Geriatric Cognitive Disorders 2008;26(1):50-7. The study found that those who ate tofu regularly had worse memory than those who did not. The study also found that tempe consumption increased memory, possibly due to its high levels of folate caused by fermentation.
Banta JP and others. Whole soybean supplementation and cow age class: Effects on intake digestion, performance and reproduction of beef cows. J Anim Sci 2008.86: 1868-78. Experiments conducted found that whole soybean supplement caused increased luteal activity in mature cows at the start of the breeding season . In 2 year old cows it caused less luteal activity than normal.