The Biological Effects of Phytoestrogens

[Guest guest]

Herman Adlercreutz MD of the University of Helsinki says

there is " no evidence in the literature suggesting that

phytoestrogens, present in amounts found in human foods,

could have biological effects, or stimulate already existing

cancer, and there is also no evidence that such

phytoestrogens could initiate cancer. " [Annals of Medicine

29: 95-120, 1997]

 

.. Why get so bothered about soy? Indeed, spices such as

thyme, oregano and turmeric bind with estrogen or

progesterone and are thus known to be hormone blockers.

[Proceedings Society Experimental Biology Medicine 21: 369-

78, 1998]

 

Soybean compounds such as IP6- phytic acid, protease inhibitors and

isoflavones, among others, appear to reduce the incidence of colon,

prostate and breast cancer. [Journal Nutrition 125: 733-743S, 1995]

 

Science backs the consumption of soy protein and/or soy

extracts (phytoestrogen-isoflavones) for males with prostate

tumors.

 

In immune-depressed rodents whose prostate glands were inoculated

with human cancer cells, soy significantly reduced the size of

tumors and the number of blood vessels that feed tumors. [Journal

Nutrition 129: 1628-35, 1999]

 

Recent data shows that neither soy, nor soy isoflavones, exert

estrogenic effects on vaginal or breast tissues in postmenopausal

females. [Journal Clinical Endocrinology 84: 3479-84, 1999]

 

In monkeys, soy phytoestrogens reduced cholesterol but did not

affect the reproductive hormones. [Journal Nutrition 126: 43-50,

1996]

 

There is a great difference between animal and human

studies.

 

Soybean cereal has been shown to interfere with the

growth of young rodents. [Medicina 59: 747-52, 1999]

 

But in infants,

there was no difference noted in weight gain nor

pancreatic enzyme production when fed soy or whey protein

formula. [scandinavian Journal Gastroenterology 32: 273-77,

1997]

 

Be wary of so-called experts who only quote animal

data to support their claims that soy is toxic or unhealthful.

 

The natural health gurus are correct on one point. Soy is

being over-promoted by billion-dollar companies that grow

the beans.

 

Estrogenic compounds are found in other natural foods such as

alfalfa sprouts and sunflower seeds, but they aren't being

aggressively marketed by multi-national agricultural companies.

 

A recent study conducted among 31 patients with high

cholesterol, who were provided 33 grams per day of soy protein

(providing 86 mg of isoflavones), reveals that LDL " bad " cholesterol

levels were significantly reduced even among subjects who were

already taking vitamin E supplements (400-800 IU).

 

The soy protein did not increase the risk of hormone-induced

cancers. [Metabolism 49: 537-43, 2000]

 

Stephen Holt, MD, writing in Natural Pharmacy, has done the best job

of sorting out information about soy. He says soy protein should be

distinguished from the soy extracts or " isoflavones " .

 

Consumption of up to 120 milligrams of soy isoflavones from soy

foods should not be considered worrisome. He says phytoestrogens in

soy are far weaker than the potent synthetic or natural estrogens

commonly prescribed to women for menopause symptoms.

 

But he does caution against excessive consumption of soy isoflavones

in " food supplements " or from fermented sources (tempeh, miso)

which Fallon and Enig advocate.

His guess is no more than 45 milligrams of conjugated isoflavones

from fermented or supplmental sources daily. [Natural Pharmacy,

April 2000]

 

While soy has gained the most attention because it is backed

by powerful agribusiness, its cousin lignan may soon become

a more desirable phytoestrogen.

 

Herman Adlercreutz, one of the world's top isoflavone researchers,

emphasizes the importance of other phytoestrogens.

 

" Don't forget the lignans, " he says. [Nutrition Science News]

We can see why researchers are turning their attention to

lignan.

 

Lignan is a normal component of the diet, albeit it is only

consumed in small amounts.

 

Lignan is most abundant in flaxseed.

Lignans in flaxseed have been compared to Tamoxifen, a hormone-

blocking drug often prescribed in cases of breast cancer. [Cancer

Letters 125: 69-76, 1998]

Adlercreutz says the areas of the world where consumption of

isoflavones and lignans are high have low rates of prostate,

breast and colon cancer.

 

Animal experiments confirm that lignans and isoflavones prevent

cancer in blood vessel disease. [Annals Medicine 29: 95-120, 1997]

 

When rates of disease are investigated by the type of phytoestrogen,

both isoflavones derived from soy, and lignans found in flaxseed,

whole-grain rye bread, berries and some vegetables, are

attributed to the reduction in breast, prostate and colon

cancer.

Where consumption of lignan is low (USA, Finland, Sweden, Australia)

breast cancer levels are high.

[baillieres Clinical Endocrinology Metabolism 12: 605-23,

1998]

 

In one study prostate tumor cells were injected into rodents

who were placed on different diets.

 

Only 50% of the sites injected with tumor cells grew tumors among

the animals on soy, and only 30% of injection sites exhibited tumors

among the animals that consumed lignan-rich rye bran.

 

The tumors that did grow were smaller in the animals consuming soy

and rye bran and there was less secretion of prostate specific

antigen (PSA).

The addition of fat to the rye bran diet reduced its protective

effect against prostate cancer.

[Prostate 42: 304-14, 2000]

 

In a study where rodents were given a tumor-promoting agent,

a diet enriched in soy did not reduce the number of colon

tumors (1.38 tumors per animal) compared to a diet low in

soy isoflavones (1.36 tumors per animals.

But a lignan-rich

rye bran diet did reduce the number of tumors! (0.17 tumors

per animal). [Carcinogenesis 20: 927-31, 1999]

 

Summary

 

Soy is not hemlock. It is not a toxin, nor does it contain

toxins.

 

Soy is like table salt. Overuse can be troublesome.

 

Learn to use it sparingly.

 

If you are looking for lignans in

your diet, throw in some flaxseeds, or cold-pressed lignan-

rich flaxseed oil. Lignan may soon create a greater stir

among health advocates than soy.

 

Correspondence:

 

Bill Sardi

Health Reporter

Knowledge of Health

Source page: http://www.tldp.com/issue/11_00/joysoy.htm

_________________

 

JoAnn Guest

mrsjoguest

DietaryTipsForHBP

www.geocities.com/mrsjoguest/Genes

[Guest guest]

, " JoAnn Guest "

<angelprincessjo> wrote:

 

" Be wary of so-called experts who only quote animal

data to support their claims that soy is toxic or unhealthful. "

 

I purchased a soy milk maker not too long ago. Then I chanced upon the

health_and_healing and this group, and stumbled onto articles with

negative views on soya, especially unfermented soya. Now the soy milk

maker is lanquishing in a corner, collecting dust. Sigh.

 

And now this postitive post on soya.

 

Who to believe. Sigh.

 

Peter

[Guest guest]

Peter. I would really like to know too, since soy was helping my hot

flashs and other symptoms. However I was also suffering from very low

body temperatures (short of hypothermia) at night, and heard that soy

might negatively affect thyroid function. So I have dropped soy.

 

I think that the answer to the question of " who to believe " probably

can be found by reading original journal articles, *researching* and

also looking at events with a eye to " common sense " understanding. If

an author has a vested interest that might influence their viewpoint.

If a population has been successfully consuming a food for a long

time that would seem to indicate that it would be safe to copy their

eating habits. So looking at the Japanese and Chinese people and

observing what form of soy they eat, and in what quantity and with

what effect is likely to yield some common sense guidelines. Another

thought I have had about this is that if the critics (or proponents)

of soy can list some scientific principle to back up their arguments,

along with scientific research, that makes the stated point of view

more palatable to me. I think that making sense of the subject of the

wisdom of consuming soy on a regular basis requires a lot of study.

 

BTW currently I am eating a lot of sunflower seeds, and I was happy to

see that they may be supplying my body with phytoestrogens. The hot

flashs have gone away, but why they came and why they went is a

mystery to me. I would like to see what amount of phytoestrogens is

in sunflower seeds.

 

Stela

 

, " Peter " <pcfw>

wrote:

>

>

> , " JoAnn Guest "

> <angelprincessjo> wrote:

>

> " Be wary of so-called experts who only quote animal

> data to support their claims that soy is toxic or unhealthful. "

>

> I purchased a soy milk maker not too long ago. Then I chanced upon the

> health_and_healing and this group, and stumbled onto articles with

> negative views on soya, especially unfermented soya. Now the soy milk

> maker is lanquishing in a corner, collecting dust. Sigh.

>

> And now this postitive post on soya.

>

> Who to believe. Sigh.

>

> Peter

[Guest guest]

I have read too much and been told by too many people that as a person with

estrogen + breast cancer to stay away from soy and will continue to do so!

 

C

 

Peter <pcfw wrote:

 

 

 

, " JoAnn Guest "

wrote:

 

" Be wary of so-called experts who only quote animal

data to support their claims that soy is toxic or unhealthful. "

 

I purchased a soy milk maker not too long ago. Then I chanced upon the

health_and_healing and this group, and stumbled onto articles with

negative views on soya, especially unfermented soya. Now the soy milk

maker is lanquishing in a corner, collecting dust. Sigh.

 

And now this postitive post on soya.

 

Who to believe. Sigh.

 

Peter

[Guest guest]

" Recent data shows that neither soy, nor soy isoflavones, exert

estrogenic effects on vaginal or breast tissues in postmenopausal

females. " [Journal Clinical Endocrinology 84: 3479-84, 1999]

 

I am premenopausal and I don't see data for that

C

 

 

 

 

 

 

" Life is not holding a good hand; Life is playing a poor hand well. "

Danish proverb

 

 

 

 

 

[Guest guest]

Hi C. I think that the main point that is being made here is that soy

does not have estrogenic effects upon the tissues mentionned. This

would apply whether one was premenopausal or postmenopausal. The

study would be easier to conduct in postmenopausal women than in

premenopausal women who would have higher natural estrogen levels.

That's the way I read this. Hope this helps.

 

Stela

 

, Christina

<cbmd3> wrote:

>

> " Recent data shows that neither soy, nor soy isoflavones, exert

> estrogenic effects on vaginal or breast tissues in postmenopausal

> females. " [Journal Clinical Endocrinology 84: 3479-84, 1999]

>

> I am premenopausal and I don't see data for that

> C

" Life is not holding a good hand; Life is playing a poor hand well. "

> Danish proverb

>

>

>

>

>

>