Are Soy Foods Safe?

[Guest guest]

Ask Natural Life: Are Soy Foods Safe?

http://www.life.ca/nl/101/soy.html

Issue #101 of Natural Life Magazine

 

Q: As a female vegetarian approaching menopause age, I eat a lot of soy

products. Recently, however, I have been told that soy can increase the

risk of breast cancer and can cause allergies. I thought it was a really

healthy food, a good source of protein and vitamin B12, and even prevented

cancer. I am now very confused. Can you help?

 

A: This is a controversial topic, so we’re not surprised that you are

confused. There are many studies discussing the disease-fighting potential

of soy foods, as well as many to the contrary. Soybeans contain all the

amino acids essential to human nutrition, which must be supplied in the

diet because they cannot be synthesized by the human body. They are also a

good source of fiber, B vitamins, calcium, and omega-3 essential fatty

acids, all important food components. The American Heart Association

recommends soy products as part of a “healthy heart” diet and in 1999, the

U.S. Food and Drug Administration (FDA) approved a health claim that can be

used on labels of soy-based foods to tout their heart-healthy benefits.

 

The FDA allowed the health claim for soy protein in response to a petition

by Protein Technologies International Inc., a leading soy producer that was

acquired by DuPont in 1997. In considering the petition, the FDA reviewed

data from 27 clinical studies submitted in the petition, which demonstrated

soy protein’s value in lowering levels of total cholesterol and low-density

lipoprotein (LDL, or “bad” cholesterol). However, research underwritten by

the soy industry, which has been working hard over the past decade or so to

create a market in North America, didn’t present the whole story, not

surprisingly.

 

And, of course, vegetarians are a good market for soy products, because

proponents claim it to be an excellent non-meat protein source.

Unfortunately, the proponents don’t publicize research like that conducted

more than 30 years ago, which found that processing soybeans renders the

fragile protein content largely ineffective. A 1971 study published as

“Studies on the Processing and Properties of Soymilk” in the J Sci Food

Agri, found that in order to neutralize the protease inhibitors (enzymes

that inhibit the digestion of protein) in soy, processors of products like

soy protein isolate and textured vegetable protein must heat it to very

high temperatures under pressure and for considerable time, a process that

denatures the protein content. It is also known that these inhibitors may

cause pancreatic disorders.

 

The Gerson Institute, a 30-year-old non-profit organization dedicated to

healing and preventing chronic and degenerative diseases through natural

therapy involving cleansing and immune system boosting, says that the

positive aspects of the soybean are overshadowed by their potential for

harm. In his classic book, A Cancer Therapy - Results of 50 Cases, Dr. Max

Gerson put soy and soy products on the forbidden list of foods for Gerson

Therapy patients. At the time, his greatest concerns were two items: the

high oil content of soy and soy products (they can add as much as nine

grams of fat per serving) and the rather high rate of allergic reactions to

soy.

 

Soy is thought by some vegans to be a source of Vitamin B12. But there is

research to indicate that Vitamin B12 analogs in soy are not absorbed and

may actually increase the body’s requirement for the vitamin. Soy also

apparently increases the body’s requirement for vitamin D.

 

Other research has found that high levels of phytic acid in soy reduce

assimilation of calcium, magnesium, copper, iron and zinc. The phytic acid

is not neutralized by ordinary preparation methods such as soaking,

sprouting and long, slow cooking.

 

You have evidently heard about the research that suggests a link between

soy and cancer, especially breast cancer. The cause of this potential

problem are isoflavones, also called phytoestrogens because they mimic

estrogen. Some studies suggest that high isoflavone levels might increase

the risk of cancer, particularly breast cancer, in postmeno- pausal women.

Research data, however, are not conclusive, and some studies show just the

opposite – under some conditions, soy may help prevent breast cancer.

 

Recent research at Belfast’s Royal Maternity Hospital indicates that

isoflavones decrease the ability of a man’s sperm to fertilize eggs.

 

Children are at especially great danger from the phytoestrogen in soy-based

formula. According to the Washington DC-based Weston A. Price Foundation,

there are many adverse effects reported in the scientific literature,

including thyroid disorders, asthma, digestive disorders, calcium

deficiencies leading to rickets, high manganese levels leading to brain

damage and endocrine disruption. A 1986 study in Puerto Rico found that use

of soy formula was strongly correlated with premature maturation in girls.

Even the American Academy of Pediatrics admits that early exposure to soy

through commercial infant formulas may be a leading cause of soy allergies

among older children and adults. The Weston A. Price Foundation is

investigating instances of serious physical or medical consequences as a

result of eating soy and is contemplating providing assistance to those who

want to pursue legal action.

 

John Henkel, a member of FDA’s public affairs staff, says that although the

research community has varying degrees of concern about a possible “dark

side” to soy consumption, one thread runs consistently through its

messages: the need for more research. A number of studies are underway,

like a long-term, multi- generational study in rats by FDA’s National

Center for Toxicological Research and a long-term follow-up study on the

safety of soy infant formula at the National Institutes of Health.

 

In the meantime, you can save yourself and your family some potential

problems by limiting soy use to fermented products like tempeh or miso. (An

estimated 70 percent of supermarket products contain soy and it is a

component of animal feed.) Fermentation reduces the phytate and

antinutrient levels of soybeans, making their nourishment available to the

human digestive system. However, make sure you are using products that

originate with organic soy beans, since most of the North American soy crop

is genetically modified and treated with dangerous chemicals.

 

And since we're talking environment, you should also consider the impact of

the burgeoning soy demand worldwide on the environment. In South American

countries like Argentina and Brazil, thousands of acres of rainforest are

being illegally cleared, rivers dammed and canals dug in order to create

more farmland to raise soy beans.