Revival Soy Doctor
I have a thyroid condition and am on levothyroxoid. Is it safe for me to take soy, and if so, how much a day? I'm also going through perimenopause and having the hot flashes... So if it would help, I'd be happy to try it. I had heard that soy and thyroid aren't a good mix.
Thanks for your help!
Thank you for your questions.
Before we get started, please read the following: We do not give medical advice. We provide nutritional information regarding Revival Soy products and information available in the public domain for the uses of soy. We advise you to discuss your personal medical issues with your physician. I hope our information will be helpful to you.
Will soy protein interfere with any of my prescription medications?
The FDA has not issued any drug interaction warnings for soy protein. No interactions in humans with common prescription medications have been shown. In fact, soy may enhance the benefits of many prescriptions. For instance, soy may help cholesterol lowering medications lower cholesterol even further. Soy may also reduce breast and endometrial stimulation caused by prescription hormones.
>>Some doctors suggest that thyroid medications be taken at a different time of the day than soy protein to maximize absorption of the medication - about 4 hours apart should be fine. You should consult your own doctor if you taking prescription medications.
Revival Soy is not a replacement for prescription medication, but can be excellent nutritional support for your dietary health plan. Revival Soy can be integrated into your current health plan to help you achieve better health.
Will soy protein affect my thyroid function?
Multiple HUMAN studies published in 1999 and 2000 have shown that soy protein DOES NOT harm thyroid function (see References 1, 2 and 3 below). Please pass this information along to your family/friends). The FDA rejected earlier claims that soy adversely affected the thyroid due to lack of evidence (Reference 4). Most importantly, in Asian countries where consumption of soy is 10 to 100 times higher than in America, no higher occurrence occurs. We have not had problems in tens of thousands of regular Revival customers. If you are taking thyroid medication, simply monitor your levels as normal with your own physician. Some doctors suggest that thyroid medications be taken at a different time of the day than soy protein to maximize absorption of the medication. Hypothyroidism is very common among women simply due to aging, therefore your physician should check your thyroid levels yearly regardless if you eat soy protein or not.
The American Foundation of Thyroid Patients has reviewed the current medical literature on soy and thyroid health and now recommends Revival Soy for all members. To learn more, visit http://www.thyroidfoundation.org
Hundreds of human studies have shown soy's benefits to menopause,
endometrial, breast, heart and bone health. Hypothyroidism has not been a
concern in these studies that we have seen.
Studies in athletes have also not shown any detrimental effects of soy
to thyroid health. The FDA has not issued a consumer warning, or stopped
infant formula from being used, or stopped soy foods from being sold and
consumed by hundreds of food manufacturers. If the FDA found evidence that
soy was dangerous, they would act on it. They reviewed the medical literature for 2 years and found no compelling, proven evidence that soy would harm the thyroid or cause cancer (Reference 4)!
Tens of thousands of customers from all over America use Revival daily
and have achieved excellent health. We haven't had any significant problems in tens of thousands of Revival users. Animal studies have shown that soy may actually increase thyroid hormone levels slightly which could help reduce cholesterol levels.
You should avoid isoflavone pills. Isoflavone pills are chemically-extracted and don't have the safety data that whole soy products have. A lot of our questions come from an in vitro study, using single, highly purified isoflavones, that in high concentrations, inhibited in vitro thyroid cells. Purified chemicals from potato skins have also been shown to be potent neurotoxins. New studies show that the isoflavone pills don't work as good as the whole soy products either. We can't expect a chemically-isolated pill to produce the same benefit and have the same
safety as soy foods.
The Japanese consume 100 times more isoflavones daily than Americans in
their diet. They have the best health and longest lifespan in the world
according to data from this summer (1999). If someone claims that they became hypothyroid after they started eating soy protein or soy isoflavones, it does not mean that soy caused it. Auto-immune diseases are the number one cause of thyroid problems followed by iodine deficient diets. They could have had a genetic predisposition for hypothyroidism.
Personal Note from Dr. Tabor: On a personal note, my entire family and many, many colleagues and friends consume Revival and other soy products daily. I talk to hundreds of Revival customers regularly that have wonderful health and great results.
My own grandmother is on Synthroid and enjoys Revival daily. The makers of Synthroid simply recommend not taking the medication at the same time during the day when eating soy products. She has not had any problems. She takes her Synthroid in the morning and the soy later during the day. No significant human data has ever shown this. It is just speculation. But, the SOLUTION is simple - monitor your Synthroid levels as you normally do with your medical doctor. He or she can adjust your Synthroid levels as needed up or down IF needed. It's that simple. You can also take your medication and soy at different times of the day to minimize any absorption problems. I doubt you will have any problems though because we haven't received any reports here.
Earlier claims that soy harmed the thyroid were based on PURIFIED CHEMICAL STUDIES (even by one of the FDA’s own scientists), which are irrelevant for whole soy products like Revival. As stated above, recent HUMAN STUDIES have disproved this theory, and the FDA’s other more senior scientists rejected any claims that whole soy protein harmed the thyroid. PLEASE READ CLEARLY: As you will see from the additional references below (References 5, 6, 7 and 8), purified chemicals from ANY vegetable or fruit, INCLUDING broccoli, potatoes, tomatoes, eggplant, brussel sprouts, cabbage, alfalfa, oats, carrots, cauliflower, turnips, etc. are very toxic (i.e. they cause cancer) to human cells if ISOLATED from the rest of the plant!! Of course, no one is saying that you shouldn’t eat vegetables and fruits!! That’s silly. The reason is that PURIFIED CHEMICALS from plants are NOT THE SAME as the whole plant, so to assert that soy causes hypothyroidism BASED ON PURIFIED CHEMICAL STUDIES is simply not correct or factual, particularly when the newest HUMAN studies show that soy is safe. Earlier preliminary human/soy/thyroid studies didn’t control for iodine deficiency, thus making them irrelevant, given the fact that 3 recent, well-designed, controlled studies have shown that soy does not harm the thyroid.
Additionally, as you will see from the last reference, the milk industry is suing the soy milk industry to stop using the word “soy milk” (Reference 9). The web sites promoting these “anti-thyroid” soy materials are funded/supported by the dairy industry. We are not against the dairy industry. We don’t even sell soy milk. Many of our customers mix their Revival with a big glass of regular milk daily! The groups/people against soy feel strongly that there is a vast “FDA conspiracy” and that the soy industry is blinded to this, which is not the case. They want to ignore the hundreds of medical studies showing that soy protein produces great benefits.
SOY ISOFLAVONES DO NOT HAVE AN ANTI-THYROID EFFECT IN POSTMENOPAUSAL WOMEN OVER 64 YEARS OF AGE. B. Bruce. G. A. Spiller and L. Holloway. Health Research and Studies Center, Los Altos, CA 94022 and Palo Alto V.A. Health Care System, Palo Alto, CA 94034. Experimental Biology 2000, San Diego, CA April 15-18, 2000.
Studies in animals, in vitro, and infants using soy-based formulas have suggested a possible anti-thyroid effect of soy. In a randomized, double blind, placebo-controlled study, we investigated the effect on thyroid function of a concentrate supplying 90 mg of soy isoflavones in 38 postmenopausal women, aged 64-83 years old, not on hormone replacement therapy (HRT). Thyroid stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3) were measured before supplementation (BS) and after 90 and 180 days.
These results suggest that there appears to be no anti-thyroid effect of soy isoflavones over six months in postmenopausal women not on HRT. Supported by a grant from Archer Daniels Midland Company.
Soy isoflavones exert modest hormonal effects in premenopausal women. Duncan AM, Merz BE, Xu X, Nagel TC, Phipps WR, Kurzer MS.
Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108, USA. J Clin Endocrinol Metab 1999 Jan;84(1):192-7
Soy isoflavones are hypothesized to be responsible for changes in hormone action associated with reduced breast cancer risk. To test this hypothesis, we studied the effects of isoflavone consumption in 14 premenopausal women. Isoflavones were consumed in soy protein powders and provided relative to body weight (control diet, 10 +/- 1.1; low isoflavone diet, 64 +/- 9.2; high isoflavone diet, 128 +/- 16 mg/day) for three menstrual cycles plus 9 days in a randomized cross-over design. During the last 6 weeks of each diet period, plasma was collected every other day for analysis of estrogens, progesterone, LH, and FSH. Diet effects were assessed during each of four distinctly defined menstrual cycle phases. Plasma from the early follicular phase was analyzed for androgens, cortisol, thyroid hormones, insulin, PRL, and sex hormone-binding globulin. The low isoflavone diet decreased LH (P = 0.009) and FSH (P = 0.04) levels during the periovulatory phase. The high isoflavone diet decreased free T3 (P = 0.02) and dehydroepiandrosterone sulfate (P = 0.02) levels during the early follicular phase and estrone levels during the midfollicular phase (P = 0.02). No other significant changes were observed in hormone concentrations or in the length of the menstrual cycle, follicular phase, or luteal phase. Endometrial biopsies performed in the luteal phase of cycle 3 of each diet period revealed no effect of isoflavone consumption on histological dating. These data suggest that effects on plasma hormones and the menstrual cycle are not likely to be the primary mechanisms by which isoflavones may prevent cancer in premenopausal women.
* Clinical trial
* Randomized controlled trial
PMID: 9920082 [PubMed - indexed for MEDLINE]
Modest hormonal effects of soy isoflavones in postmenopausal women. Duncan AM, Underhill KE, Xu X, Lavalleur J, Phipps WR, Kurzer MS.
Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108, USA. J Clin Endocrinol Metab 1999 Oct;84(10):3479-84
Soy isoflavones have been hypothesized to exert hormonal effects in postmenopausal women. To test this hypothesis, we studied the effects of three soy powders containing different levels of isoflavones in 18 postmenopausal women. Isoflavones were consumed relative to bodyweight [control: 0.11 +/- 0.01; low isoflavone (low-iso): 1.00 +/- 0.01; high isoflavone (high-iso): 2.00 +/- 0.02 mg/kg/day] for 93 days each in a randomized crossover design. Blood was collected on day 1 of the study (baseline) and days 36-38, 64-66, and 92-94 of each diet period, for analysis of estrogens, androgens, gonadotropins, sex hormone binding globulin (SHBG), prolactin, insulin, cortisol, and thyroid hormones. Vaginal cytology specimens were obtained at baseline and at the end of each diet period, and endometrial biopsies were performed at baseline and at the end of the high-iso diet period, to provide additional measures of estrogen action. Overall, compared with the control diet, the effects of the low-iso and high-iso diets were modest in degree. The high-iso diet resulted in a small but significant decrease in estrone-sulfate (E1-S), a trend toward lower estradiol (E2) and estrone (E1), and a small but significant increase in SHBG. For the other hormones, the few significant changes noted were also small and probably not of physiological importance. There were no significant effects of the low-iso or high-iso diets on vaginal cytology or endometrial biopsy results. These data suggest that effects of isoflavones on plasma hormones per se are not significant mechanisms by which soy consumption may exert estrogen-like effects in postmenopausal women. These data also show that neither isoflavones nor soy exert clinically important estrogenic effects on vaginal epithelium or endometrium.
* Clinical trial
* Randomized controlled trial
PMID: 10522983 [PubMed - indexed for MEDLINE]
Women's Health & Soy Protein Overview
Benefits for women of all ages!
Soy alleviates menopausal and perimenopausal symptoms: Soy protein can significantly improve your midlife comfort and health. (1,2,3,4) Symptoms such as hot flashes, night sweats, mood swings, fatigue, vaginal dryness, loss of libido, headaches, anxiety and insomnia can be controlled with Revival. Soy is extremely safe and has never been linked to breast or endometrial cancer. In fact, soy consumption may reduce the risk of certain cancers including breast, endometrial (uterine) and colon cancer. (3,5,6,7,8,9,10,11) Poplulations with the highest soy consumption have the lowest rates of breast and endometrial cancers.
Soy protein may exert positive effects on bone density in women of all ages. (12,13,14) Numerous animal and human studies have shown that soy protein can help you maintain a strong skeletal system and healthy joints.
Soy is considered extremely safe: soy protein does not stimulate cell growth in breast or endometrial (uterine) tissues. (15) Soy inhibits estrogen-induced breast and endometrial cell proliferation. (16) Soy may function as a selective estrogen, producing the benefits but not the risks associated with traditional hormone replacement therapy (commonly referred to as HRT). (15,17,18)
Soy protein lowers cholesterol levels and lowers heart disease risk - the #1 killer of women and men. (4,19) On October 26th, 1999, the FDA approved a new health claim that soy protein reduces risk of coronary heart disease. (20)
Soy may also benefit women on HRT by blocking breast and uterine tissue proliferation caused by estrogen (16), and producing additive benefits with estrogen to lower cholesterol/heart disease risk and improving blood vessel reactivity. (19)
Human studies show that soy protein helps decrease fat and increases lean tissue. (22) Soy is also an excellent connective tissue stimulant for better hair/skin/nails.
The key to results is to eat enough soy for results. Each Revival Soy is the amount needed for results and benefits. The taste is excellent!
Please let me know if I can help further.
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* Read Dr. Tabor's last guest transcript
* Revival is a dietary supplement. These statements have not been evaluated by the Food and Drug Administration. Revival is not intended to diagnose, treat, cure or prevent any disease. The information presented on our web site is not intended to take the place of your personal physician's advice.
Please consult a physician before using if you are pregnant or nursing,taking medication or suffer from chronic disease.
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