Kelly Harford, M.C., C.N.C. See book keywords and concepts |
Traditional Asian populations aren't downing quarts of overly sweetened, highly processed soy milk or popping supplements containing concentrated soy isoflavones, as is becoming popular in this country. Even more important to note, the traditional Asian diet primarily consists of whole, fresh, natural foods, including sea vegetables, which are packed with vital nutrients and one of the richest sources of absorbable calcium. They also eat a lot of fish, small amounts of meat, and little to no dairy products or processed foods. |
Amarjit S. Basra See book keywords and concepts |
To further spark debate on the healthful properties of soy isoflavones, recent data questioned their bioavailability in humans.7 Finally, it should be stated that the proteic components of soy exhibit remarkable cholesterol-lowering properties, more evident in hypercholesterolemic subjects, that render a soy-based hypocholesterolemic diet very cost-effective. Based on current research data, most of the cardioprotective effects of a diet in which soy plays a relevant role are to be attributed to its proteic component.8
COCOA
Cocoa (Theobroma cacao L. |
Steven G. Pratt, M.D. and Kathy Matthews See book keywords and concepts |
Once the health benefits of soy became well publicized, it wasn't long before soy isoflavones were available in health food stores. These supplements, containing concentrated soy isoflavones, are promoted as being beneficial particularly to women as relief from menopausal symptoms. You know my answer: if you want to get the health benefits of soy, you must rely on the whole food. For one thing, no one is certain what's in various supplements: they may contain more or less isoflavones than they claim. |
Dr. Michael Heinrich, Joanne Barnes, Simon Gibbons and Elizabeth M. Williamson See book keywords and concepts |
In an open study of 190 healthy postmenopausal women given 35 mg of soy isoflavones, a reduction in the number of hot flushes was found (Albert et al 2002), but no improvement was seen in women with breast cancer given a beverage containing 90 mg of soy isoflavones. A high soy diet improved measures of short- and long-term memory in healthy young men and women (File et al 2001). There is still much work to be done on the clinical effects of the isoflavones in soya, but at present it appears that they are beneficial with few adverse effects (see Mason 2001). |
Michael Friedman, ND See book keywords and concepts |
However, a diet high in soy isoflavones (128 mg/day) has been reported to induce a modest decrease in fT3 levels during the early follicular phase of the cycle in premenopausal women.133 Whether the soy is affecting peripheral metabolism or increasing binding to TBPA, albumin, or TBG is unclear.
The effects of 30 grams of soybeans fed daily for 1-3 months to 37 healthy adults were investigated. Soybean consumption resulted in a significant increase in TSH levels, although levels remained within normal limits. |
Wdiile research has not determined the exact effect of soy products and soy isoflavones on the peripheral metabolic fate of thyroid hormones, excessive soy consumption might be best approached cautiously among subjects with suspected impairment of peripheral metabolic pathways.
Potential Influence of Flavonoids on Thyroid Hormone Metabolism
Flavonoids, both naturally occurring and synthetic derivatives, have the potential to disrupt thyroid hormone metabolism in vitro. |
Duncan AM, Merz BE, Xu X, et al. soy isoflavones exert modest hormonal effects in premenopausal women. J Clin Endocrinol Metab 1999;84:192-97.
134. Ishizuki Y, HirookaY, MurataY, Togashi K The effects on the thyroid gland of soybeans administered experimentally in healthy subjects. Nippon Naibunpi Gakkai Zasshi 1991;67:622-29. [Article in Japanese]
135. Kohrle J. The trace components-selenium and flavonoids-affect iodothyronine deiodinases, thyroid hormone transport and TSH regulation. Acta Med Austriaca 1992;19:S13-S17.
136. Spanka M, Hesch RD, Irmscher K, Kohrle J. |
Alan R. Gaby, M.D., Jonathan V. Wright, M.D., Forrest Batz, Pharm.D. Rick Chester, RPh., N.D., DipLAc. George Constantine, R.Ph., Ph.D. Linnea D. Thompson, Pharm.D., N.D. See book keywords and concepts |
Of 154 healthy postmenopausal women who received 150 mg of soy isoflavones per day for five years, 3.9% developed an abnormal proliferation of the tissue that lines the uterus (endometrial hyperplasia). In contrast, none of 144 women who received a placebo developed uterine hyperplasia.31 Although no case of uterine cancer was diagnosed during the study, endometrial hyperplasia is a potential forerunner of uterine cancer. The amount of isoflavones used in this study is two to three times as much as that used in many other studies. |
The Editors of FC&A See book keywords and concepts |
Studies suggest that soy isoflavones make radiation treatment for prostate cancer more effective. Tests are currently under way to see if eating soy foods before treatment helps.
It may be that calcium interferes with your body's use of vitamin D, which seems to protect against prostate cancer. Results were the same whatever the source — dairy foods, fortified juices, or supplements.
Healthy habits
Keep your prostate healthy with a few simple lifestyle changes to go along with your healthy diet.
• Get regular exercise.
• Maintain a healthy weight.
• Relax to reduce stress. |
Kaayla T. Daniel, PhD, CCN See book keywords and concepts |
In vitro studies prove that soy isoflavones are potent inhibitors of 17 B-hydroxysteroid oxidoreductase and are able to inhibit the synthesis and metabolism of estradiol, testosterone and other steroid hormones.1820
Isoflavones can also inhibit enzymes called protein tyrosine kinases, which add phosphate to intracellular proteins and are necessary for the action of insulin-like and epidermal growth factors. |
Dr. Michael Heinrich, Joanne Barnes, Simon Gibbons and Elizabeth M. Williamson See book keywords and concepts |
In an open study of 190 healthy postmenopausal women given 35 mg of soy isoflavones, a reduction in the number of hot flushes was found (Albert et al 2002), but no improvement was seen in women with breast cancer given a beverage containing 90 mg of soy isoflavones. A high soy diet improved measures of short- and long-term memory in healthy young men and women (File et al 2001). There is still much work to be done on the clinical effects of the isoflavones in soya, but at present it appears that they are beneficial with few adverse effects (see Mason 2001). |
Kaayla T. Daniel, PhD, CCN See book keywords and concepts |
S„ Sydney, Australia
ž Providing no information on the ages at which formula feeding ended, the dose length or the quantity of the soy isoflavones (all of which are basic requirements of valid toxicology studies).86
ž Using the criteria "trade school, college and post college" as a measure of intelligence, thus rating a graduate of a beauty school at the same level as someone who received a doctorate degree. The researchers could only have obtained meaningful conclusions by breaking these out into separate categories. |
Adults attempting to prevent hormonally driven breast and prostate cancers might possibly benefit from the pharmaceutical use of soy isoflavones acting as antagonists to endogenous estrogens. (The evidence is mixed.) Babies, however, can be irreversibly harmed if clogged receptor sites delay or stop normal, necessary development.14
Soy phytoestrogens can also obstruct the very production of estrogen and testosterone. By occupying—and inactivating—hormone receptor sites in the brain, they block messages normally transmitted by cell signal transduction pathways. |
Phyllis A. Balch, CNC See book keywords and concepts |
Soy and soy isoflavones may help to alleviate hot flashes associated with menopause. A high intake of phytoestrogens is thought to explain why hot flashes and other menopausal symptoms rarely occur among women in Asian cultures.
Q Do not consume any animal products except for those recommended in this section. Avoid dairy products—limit your consumption to small amounts of low-fat yogurt or buttermilk. Dairy products and meat promote hot flashes. |
Current research indicates that soy isoflavones may enhance coronary blood flow and prevent blocked arteries.
Q According to some studies, magnesium supplementation can correct some types of irregular heartbeat, and could save the lives of many people with heart trouble.
Q The mechanisms responsible for omega-3 fatty acids' reduction of cardiovascular disease risk are still being studied. However, it appears that benefits include decreases in triglyceride levels and blood clots, lower risk of sudden death, improved arterial health, and lower blood pressure. |
Jonathan V. Wright, M.D. and Alan R. Gaby, M.D. See book keywords and concepts |
In women with too much estrogen, on the other hand, soy isoflavones compete with the stronger human estrogens, possibly reducing the risk of breast cancer and other hormone-dependent cancers.3 Soybeans have also been shown to prevent atherosclerosis (hardening of the arteries) in experimental animals4—an effect that may be due at least in part to the isoflavones.
Many other foods contain "healthful" compounds. For example, broccoli, brussels sprouts, cabbage, and cauliflower contain indole-3-carbinol and several other compounds that appear to have anticancer activity. |
Joe Graedon, M.S. and Teresa Graedon, Ph.D. See book keywords and concepts |
I dreaded the next month, fearing the success of the soy isoflavones had been a fluke, but it has worked for 3 months in a row.
Doctors have also experimented with longer-acting triptans, particularly Amerge, Frova, and Naramig. These drugs are frequently used to stop a headache once it has begun, but they also can be used when a headache is anticipated to prevent the menstrual
^77 migraine. In some women, oral contraceptives will help prevent menstrual migraines, especially those that limit the number of menstrual periods to just a few each year. |
Alan R. Gaby, M.D., Jonathan V. Wright, M.D., Forrest Batz, Pharm.D. Rick Chester, RPh., N.D., DipLAc. George Constantine, R.Ph., Ph.D. Linnea D. Thompson, Pharm.D., N.D. See book keywords and concepts |
The mild estrogenic activity of soy isoflavones may ease menopause (page 311) symptoms for some women, without creating estrogen-related problems. In one double-blind trial, supplementation with 60 grams of soy protein per day for 12 weeks led to a 45% decrease in the number of hot flashes, compared with a 30% reduction in the placebo group, a statistically significant difference.11 In addition, soy may help regulate hormone levels in premenopausal women.12
Soy may also be beneficial in preventing osteoporosis (page 333). Isoflavones from soy have protected against bone loss in animal studies. |
Most animal studies report that soybeans and soy isoflavones protect against mammary cancer.69 However, the protective effect in animals have occurred primarily when soy has been administered before puberty.70 If the same holds true in humans, consuming soy products in adulthood might provide little, if any, protection against breast cancer.
The findings of several recent studies suggest that consuming soy might, under some circumstances, increase the risk of breast cancer. |
When premenopausal women were given soy isoflavones, an increase in breast secretions resulted—an effect thought to elevate the risk of breast cancer.81 In yet another trial, healthy breast cells from women previously given soy supplements containing isoflavones showed an increase in proliferation rates—an effect that might also increase the tisk of bteast cancer.82
The commonly held belief that consuming soybeans or isoflavones such as genistein will protect against breast cancer is, therefore, far from proven. |
Nonetheless, considerable preliminary information has been gathered about the relationship between soy isoflavones and breast cancer. For more information, see the discussion about soy in Dietary changes, above.
Conjugated linoleic acid (page 499) Preliminary animal and test tube research suggests that CLA might reduce the risk of cancers (page 87) at several sites, including breast, prostate (page 371), colorectal (page 123), lung (page 298), skin, and stomach.214'215'216'217 Whether CLA will have a similar protective effect for people has yet to be demonstrared in human research. |
Soy isoflavones are also currently being studied to see if they help fight cancer.
In a small, preliminary trial, rutoside (500 mg twice daily), a derivative of the flavonoid, rutin, combined with vitamin C (page 604) (500 mg twice daily) produced marked improvement in three women with progressive pigmented purpura (PPP), a mild skin condition.3 Although not a serious medical condition, cosmetic concerns lead persons with PPP to seek treatment with a variety of drugs. |
Kaayla T. Daniel, PhD, CCN See book keywords and concepts |
Mice injected with large doses of the soy isoflavones genistein soon after birth showed altered mammary gland development (possibly reducing their susceptibility to chemically induced tumor development as adults) as well as impaired ovarian follicular development and cycles (impairing fertility).74 76
To date, the most important study looking at effects on human female infants took place in Puerto Rico. |
Schuyler W. Lininger, Jr. DC See book keywords and concepts |
One study of soy research found that 65% of 26 animal-based cancer studies showed a protective effect of soy or soy isoflavones.2 Human research also suggests a protective role of soy against cancer.34
A meta-analysis study that pooled 38 trials for reanalysis reported that a soy diet led to cholesterol (p. 79) reductions in 89% of the studies. Increasing soy intake was associated with a 23 mg per deciliter drop in total cholesterol levels.5 Exactly how soy lowers cholesterol remains in debate.6
The mild estrogen activity of soy isoflavones may ease menopause (p. |
David Hoffman, FNIMH, AHG See book keywords and concepts |
Given the protective benefits of soy isoflavones against breast cancer alone, the regular consumption of soy foods is encouraged.
Herbal and Nutritional Treatments for Osteoporosis
Herbal and nutritional treatment cannot eliminate osteoporosis, but it can slow the process. The North American tradition relies on herbs such as Equisetum arvense (horsetail), Avena sativa (oat straw), and Urtica dioica (nettles) for the long-term treatment of osteoporosis. Some believe that they are effective because they have a high calcium content. |
Janet Zand, LAc, OMD, Allan N. Spreed, MD, CNC, James B. LaValle, RPh, ND See book keywords and concepts |
Research suggests that soy isoflavones can help to maintain bone density. They are also good for reducing menopausal discomforts, the risk of certain types of cancer, and, possibly, cardiovascular risk. Take 1,000 milligrams once or twice daily. Ipriflavone, a synthetic supplement based on soy isoflavones, has been reported to show promising results in stopping bone loss as well. The recommended dose is 200 milligrams three times a day.
¦ A natural trace mineral combination is an excellent adjunct to your calcium supplement. |
The Life Extension Editorial Staff See book keywords and concepts |
According to peer-reviewed scientific studies, soy isoflavones protect against menopausal disorders that are notmally treated by FDA-approved estrogen dmgs. Unlike these synthetic dmgs, phytoestrogens from soy have been shown to:
• Prevent cancer at multiple sites
• Prevent gallstones
• Protect kidney function
• Stimulate bone formation
• Lower cholesterol levels
• Inhibit the oxidation of LDL cholesterol
• Inhibit the development or progression of atherosclerosis
Unlike estrogen dmgs, phytoestrogens have a balancing effect on the body. |
the Editors of FC&A Medical Publishing See book keywords and concepts |
How many soy isoflavones do you consume each day?
Food
Milligrams of isoflavones*
Serving size (approximate)
Bacon, meatless
1.9
2 strips (1/2 ounce)
Granola bar (hard, plain)
.1
3.5 ounces
Harvest Burger,
(all vegetable protein patty)
8.2
1 patty
Infant formula, Prosobee® and Isomil® with iron, ready-to-feed
8
1 cup
How many soy isoflavones do you consume each day?
Food
Milligrams of isoflavones*
Serving size (approximate)
Miso
43.0
111 cup
Peanuts, raw
.3
1/2 cup
Soy breakfast links (45 g)
1.7
2 links
Soy cheese, cheddar
7
3. |
Grace Ross Lewis See book keywords and concepts |
What are the benefits of soy isoflavones?
Soy isoflavones are a group of phytochemicals only found in soybeans. The isoflavones genistein and daidzein have strong antioxidant benefits that reduce the risk of heart disease and cancer, as well as other diseases.
121. Do soybeans contain other beneficial chemicals?
Soybeans contain saponins that are a group of phytonutrients with immunity and disease-fighting potential. They also act to increase immunity, prevent cancer, and fight infections. Soy is also high in protein, vitamin E, lecithin, and omega-3 fatty acids.
122. |
Steven G. Pratt, M.D. and Kathy Matthews See book keywords and concepts |
Whichever soy protein powder you choose, be sure that it's not fortified with extra soy isoflavones.
Soy Flour: Soy flour has been processed from whole ground soybeans. Use it to increase the protein content of breads, cakes, and cookies. Soy flour contains no gluten, so it cannot be used to replace the wheat flour in baking. But you can use it to supplement your other flour: in yeast-raised breads: use 2 tablespoons of soy flour per cup of wheat flour; with quick breads, you can replace up to one-quarter of the wheat flour with soy flour. |