Soybeans have a nice new name –Edamame. Sounds kind of exotic and sophisticated, doesn’t it? Since the 1990′s when marketers got behind this new name, sales of soybeans have skyrocketed, and an amazing array of products made with soy have proliferated store shelves. Does this mean you should jump on the soy bandwagon too?
Writings about the soybean date back to 3000 B.C., when the emperor of China listed the virtues of soybean plants
to regenerate soil for future crops. His praises centered on the root of the plant, not the bean. These ancient writings suggested that the Chinese recognized the unfitness of soybeans for human consumption in their natural form. Now, 5000 years later, we have forgotten what the Chinese knew about the anti-nutritive qualities of soybeans and are consuming them in record amounts. We have turned our backs on the Chinese wisdom that says the only soybean worth eating is one that has been fermented.
The key to releasing the soybeans nutrients has been known for thousands of years
About 1000 B.C. some smart Chinese person discovered that a mold, when allowed to grow on soybeans, destroyed the natural plant toxins present and made the nutrients in the beans available to the body. This process became known as fermentation
and led to the creation of the still popular foods tempeh, miso, and natto.
A few centuries later, a simpler process was developed to prepare soybeans for consumption. After lengthy soaking
and cooking, the beans were treated with nigari
, a substance found in seawater. The end product was tofu
. During the Ming dynasty, fermented
soy appeared in the Chinese Materia Medica
, the book behind traditional Chinese medicine
(TCM) as a nutritionally important food and an effective remedy for diseases.
Non fermented soybeans contain potent anti-nutrients
In their natural form, soybeans contain phytochemicals with highly negative effects on the human body. The three major anti-nutrients are phytate
, enzyme inhibitors and goitrogens.
These anti-nutrients are nature’s way of protecting the soybean plant so it can live long enough to effectively reproduce. They function as the plant’s immune system, offering protection from the radiation of the sun, and from invasion by bacteria, viruses, or fungi. They make the soybean plant unappetizing to foraging animals. All plants have some anti-nutrient
properties, but the soybean plant is especially rich in these chemicals. If they aren’t removed by extensive preparation such as fermentation or soaking, soybeans are one of the worst foods a person can eat.
Unfermented soy has been linked to digestive distress
, immune system breakdown, PMS
, endometriosis, reproductive problems for men and women, allergies, ADHD
, higher risk of heart disease and cancer, malnutrition, osteoporosis, and loss of libido.
Groups most at risk of experiencing negative effects from the anti-nutrient properties of soy are infants taking soy baby formula, vegetarians eating a high soy diet
, and mid-life women going heavy on the soy foods thinking they will help with symptoms of menopause.
Soybeans contain high levels of phytates
All legumes contain phytate (also known as phytic acid) to some extent, but the soybean is loaded with it. Phytate works in the gastrointestinal tract to tightly bind minerals such as zinc, copper, iron, magnesium and calcium. It has a particularly strong affinity for zinc, a mineral that supports wound healing, protein synthesis, reproductive health, nerve function, and brain development
. It is believed that people living in third world countries are shorter than those in developed countries because of zinc deficiency caused by eating too many improperly prepared legumes. There is also evidence that mental development can be negatively impacted by a diet high in phytate.
In most legumes such as other varieties of beans, soaking is enough to break down most of the phytate content. However the soybean requires the enzymes released in the fermentation process to reduce its phytate content to the point where it becomes fit for consumption. This means that fermented soy foods like miso and tempeh have the lowest levels of phytate and are the best choices for anyone wishing to eat soybean products,. Tofu is also a good choice, as long as care is taken to eat it as the Asians do, with mineral rich
sea vegetables and some other protein source to make up for its nutrient depleting effects.
Whole soybeans, soy milk, soy chips, soy protein bars, soy flour and all the other myriad products made from soybeans
and advertised as health foods have much higher levels of phytate and are not worth consuming.
Unfermented soy products are rich in enzyme inhibitors
When food is eaten, digestive enzymes
such as amylase lipase and protease are secreted into the digestive tract to help break it down and free nutrients for assimilation into the body. The high content of enzyme inhibitors in unfermented soybeans interferes with this process and makes carbohydrates and proteins from soybeans impossible to completely digest. When foods are not completely digested because of enzyme inhibitiors, bacteria in the large intestine try to do the job, and this can cause discomfort, bloating, and embarrassment. Anyone with naturally low levels
of digestive enzymes, such as elderly people, suffer the most from the enzyme inhibiting action of soy.
Soybeans can block production of thyroid hormone
Soybeans have a high content of goitrogens
, substances that can block the production of thyroid hormone
as well as cause goiter formation. This is a big deal because low thyroid activity plagues women in America, particularly middle-aged women. Thyroid hormone stokes the cellular furnaces, known as mitochrondia
. So when thyroid production is low, energy levels as well as body heat are also low. Low thyroid level
is what makes old people move so slowly and seem like every action is a huge chore. Low thyroid
means the action of the heart is reduced, resulting in lack of oxygen to the cells, a prime condition for cancer development.
, an isoflavone found in soybeans, can also block thyroid production. Phytate can accentuate these effects because it binds up zinc and copper, leaving little of these important minerals
available to make thyroid hormone.
A transport protein called GLUT1 is shut down by genistein. This protein sends glucose into the cells where it is used to generate energy. Slowing the transport of glucose means less energy production not only of thyroid hormone, but of every other action in the body.
Another way in which soy isoflavones reduce energy in the body is by inhibiting tyrosine kinases, enzymes involved in the transfer of energy from one molecule to another. These enzymes drive cell division, memory consolidation, tissue repair, and blood vessel maintenance and regeneration.
It is this action of regulating cell division
that has made genistein a popular substance for fighting cancer. When research on this anti-cancer effect of genistein became known, the soy industry feverishly developed products that would appeal to Western women looking for genistein. In the middle of all this excitement, little attention was paid to how the energy reducing effects of genistein lowered cellular energy
in normal cells as well.
The benefits of genistein come at a high cost
Women have been encouraged to use high genistein soy products to alleviate symptoms
of menopause and as a guard against bone loss and breast cancer. But given the full range of effects of genistein in the body, high consumption could result in age-related memory loss
. Commercial soybean products offer genistein levels as high as 20 to 60 mg per serving. Asians are presented as an example of the benefits of eating soybeans, and their incidence of breast cancer and osteoporosis is low. However, the Asian diet of fermented
soybean products such as miso and tempeh includes only around 5 mg of genistein a day.
Genistein slows the growth of blood vessels to tumors, another action that makes it popular as a cancer fighter. However, it has the same effect on blood vessels serving normal cells. Eating a regular diet high in genistein could result in the starvation of healthy blood cells, and a reduction in their oxygen supply.
In a graphic example of how genistein slows cellular energy, a study found that eating high levels of it slowed hair growth by 60 to 80 percent
In the late 1990’s a study of 8,000 Asian men showed that those consuming the highest amounts of tofu had smaller brain size and nearly three times the rate of senile dementia
as those who at the lowest amounts. These results suggest that eating foods high in isoflavones such as soy protein isolates may accelerate the aging of the brain.
Fermentation releases the nutrients and transforms soybeans to nutritious food
With soy foods, a little goes a long way. The nutrients found in fermented soy products such as miso, tempeh, and natto can be beneficial in the moderate amounts found in the typical Asian diet, but have the potential to do harm in higher amounts. In China and Japan, only about one ounce of fermented soy food is eaten on a daily basis.
When fermented soy foods are used in small amounts they help build the inner ecosystem
, providing a wealth of friendly microflora to the intestinal tract that can help with digestion and assimilation of nutrients and boost immunity.
Dr. John Lee, the now deceased Professor from the Harvard Medical School and author of several books on women’s health, recommended that people wishing to consume soy eat only miso, tempeh and natto. Tofu can also be eaten in the Asian manner of accompanying it with high protein and high mineral sources
. Eating small amounts of these foods will provide the cancer protective effects of genistein without causing the other potential problems of genistein. He recommended avoiding genistein and isoflavone supplements and soy protein isolates.
For more information:
Dr. John Lee, MD, What Your Doctor May Not Tell You About Breast Cancer, Warner Books.
About The Author:
Barbara is a school psychologist, a published author in the area of personal finance, a breast cancer survivor using \”alternative\” treatments, a born existentialist, and a student of nature and all things natural.