Ăn Đậu Nành Và Sản Phẩm Đậu Nành Lợi Hại Ra Sao ?


Question Marks Over Gras Status



tải về 252.53 Kb.
trang4/6
Chuyển đổi dữ liệu24.07.2016
Kích252.53 Kb.
#4039
1   2   3   4   5   6

Question Marks Over Gras Status
Lurking in the background of industry hype for soy is the nagging question of whether it's even legal to add soy protein isolate to food. All food additives not in common use prior to 1958, including casein protein from milk, must have GRAS (Generally Recognized As Safe) status. In 1972, the Nixon administration directed a re-examination of substances believed to be GRAS, in the light of any scientific information then available. This re-examination included casein protein that became codified as GRAS in 1978. In 1974, the FDA obtained a literature review of soy protein because, as soy protein had not been used in food until 1959 and was not even in common use in the early 1970s, it was not eligible to have its GRAS status grandfathered under the provisions of the Food, Drug and Cosmetic Act.71

The scientific literature up to 1974 recognized many antinutrients in factory-made soy protein, including trypsin inhibitors, phytic acid and genistein. But the FDA literature review dismissed discussion of adverse impacts, with the statement that it was important for "adequate processing" to remove them. Genistein could be removed with an alcohol wash, but it was an expensive procedure that processors avoided. Later studies determined that trypsin inhibitor content could be removed only with long periods of heat and pressure, but the FDA has imposed no requirements for manufacturers to do so.

The FDA was more concerned with toxins formed during processing, specifically nitrites and lysinoalanine.72 Even at low levels of consumption - averaging one-third of a gram per day at the time - the presence of these carcinogens was considered too great a threat to public health to allow GRAS status.

Soy protein did have approval for use as a binder in cardboard boxes, and this approval was allowed to continue, as researchers considered that migration of nitrites from the box into the food contents would be too small to constitute a cancer risk. FDA officials called for safety specifications and monitoring procedures before granting of GRAS status for food. These were never performed. To this day, use of soy protein is codified as GRAS only for this limited industrial use as a cardboard binder. This means that soy protein must be subject to premarket approval procedures each time manufacturers intend to use it as a food or add it to a food.

Soy protein was introduced into infant formula in the early 1960s. It was a new product with no history of any use at all. As soy protein did not have GRAS status, premarket approval was required. This was not and still has not been granted. The key ingredient of soy infant formula is not recognized as safe.

The Next Asbestos?
"Against the backdrop of widespread praise...there is growing suspicion that soy - despite its undisputed benefits - may pose some health hazards," writes Marian Burros, a leading food writer for the New York Times. More than any other writer, Ms Burros's endorsement of a low-fat, largely vegetarian diet has herded Americans into supermarket aisles featuring soy foods. Yet her January 26, 2000 article, "Doubts Cloud Rosy News on Soy", contains the following alarming statement: "Not one of the 18 scientists interviewed for this column was willing to say that taking isoflavones was risk free." Ms Burros did not enumerate the risks, nor did she mention that the recommended 25 daily grams of soy protein contain enough isoflavones to cause problems in sensitive individuals, but it was evident that the industry had recognized the need to cover itself.

Because the industry is extremely exposed...contingency lawyers will soon discover that the number of potential plaintiffs can be counted in the millions and the pockets are very, very deep. Juries will hear something like the following: "The industry has known for years that soy contains many toxins. At first they told the public that the toxins were removed by processing. When it became apparent that processing could not get rid of them, they claimed that these substances were beneficial. Your government granted a health claim to a substance that is poisonous, and the industry lied to the public to sell more soy."



The "industry" includes merchants, manufacturers, scientists, publicists, bureaucrats, former bond financiers, food writers, vitamin companies and retail stores. Farmers will probably escape because they were duped like the rest of us. But they need to find something else to grow before the soy bubble bursts and the market collapses: grass-fed livestock, designer vegetables...or hemp to make paper for thousands and thousands of legal briefs.


Extracted from Nexus Magazine, Volume 7, Number 3 (April-May 2000)

ENDNOTES:

1. Program for the Third International Symposium on the Role of Soy in Preventing and Treating Chronic Disease, Sunday, October 31, through Wednesday, November 3, 1999, Omni Shoreham Hotel, Washington, DC.
2. Houghton, Dean, "Healthful Harvest", The Furrow, January 2000, pp. 10-13.
3. Coleman, Richard J., "Vegetable Protein - A Delayed Birth?" Journal of the American Oil Chemists' Society 52:238A, April 1975.
4. See www/unitedsoybean.org.
5. These are listed in www.soyonlineservice.co.nz.
6. Wall Street Journal, October 27, 1995.
7. Smith, James F., "Healthier tortillas could lead to healthier Mexico", Denver Post, August 22, 1999, p. 26A.
8. "Bakery says new loaf can help reduce hot flushes", Reuters, September 15, 1997.
9. "Beefing Up Burgers with Soy Products at School", Nutrition Week, Community Nutrition Institute, Washington, DC, June 5, 1998, p. 2.
10. Urquhart, John, "A Health Food Hits Big Time", Wall Street Journal, August 3, 1999, p. B1
11. "Soyabean Milk Plant in Kenya", Africa News Service, September 1998.
12. Simoons, Frederick J., Food in China: A Cultural and Historical Inquiry, CRC Press, Boca Raton, 1991, p. 64.
13. Katz, Solomon H., "Food and Biocultural Evolution: A Model for the Investigation of Modern Nutritional Problems", Nutritional Anthropology, Alan R. Liss Inc., 1987, p. 50.
14. Rackis, Joseph J. et al., "The USDA trypsin inhibitor study. I. Background, objectives and procedural details", Qualification of Plant Foods in Human Nutrition, vol. 35, 1985.
15. Van Rensburg et al., "Nutritional status of African populations predisposed to esophageal cancer", Nutrition and Cancer, vol. 4, 1983, pp. 206-216; Moser, P.B. et al., "Copper, iron, zinc and selenium dietary intake and status of Nepalese lactating women and their breastfed infants", American Journal of Clinical Nutrition 47:729-734, April 1988; Harland, B.F. et al., "Nutritional status and phytate: zinc and phytate X calcium: zinc dietary molar ratios of lacto-ovovegetarian Trappist monks: 10 years later", Journal of the American Dietetic Association 88:1562-1566, December 1988.
16. El Tiney, A.H., "Proximate Composition and Mineral and Phytate Contents of Legumes Grown in Sudan", Journal of Food Composition and Analysis (1989) 2:6778.
17. Ologhobo, A.D. et al., "Distribution of phosphorus and phytate in some Nigerian varieties of legumes and some effects of processing", Journal of Food Science 49(1):199-201, January/February 1984.
18. Sandstrom, B. et al., "Effect of protein level and protein source on zinc absorption in humans", Journal of Nutrition 119(1):48-53, January 1989; Tait, Susan et al., "The availability of minerals in food, with particular reference to iron", Journal of Research in Society and Health 103(2):74-77, April 1983.
19. Phytate reduction of zinc absorption has been demonstrated in numerous studies. These results are summarised in Leviton, Richard, Tofu, Tempeh, Miso and Other Soyfoods: The 'Food of the Future' - How to Enjoy Its Spectacular Health Benefits, Keats Publishing, Inc., New Canaan, CT, USA, 1982, p. 1415.
20. Mellanby, Edward, "Experimental rickets: The effect of cereals and their interaction with other factors of diet and environment in producing rickets", Journal of the Medical Research Council 93:265, March 1925; Wills, M.R. et al., "Phytic Acid and Nutritional Rickets in Immigrants", The Lancet, April 8,1972, pp. 771-773.
21. Rackis et al., ibid.
22. Rackis et al., ibid., p. 232.
23. Wallace, G.M., "Studies on the Processing and Properties of Soymilk", Journal of Science and Food Agriculture 22:526-535, October 1971.
24. Rackis, et al., ibid., p. 22; "Evaluation of the Health Aspects of Soy Protein Isolates as Food Ingredients", prepared for FDA by Life Sciences Research Office, Federation of American Societies for Experimental Biology (9650 Rockville Pike, Bethesda, MD 20014), USA, Contract No. FDA 223-75-2004, 1979.
25. See www/truthinlabeling.org.
26. Rackis, Joseph, J., "Biological and Physiological Factors in Soybeans", Journal of the American Oil Chemists' Society 51:161A-170A, January 1974.
27. Rackis, Joseph J. et al., "The USDA trypsin inhibitor study", ibid.
28. Torum, Benjamin, "Nutritional Quality of Soybean Protein Isolates: Studies in Children of Preschool Age", in Soy Protein and Human Nutrition, Harold L Wilcke et al. (eds), Academic Press, New York, 1979.
29. Zreik, Marwin, CCN, "The Great Soy Protein Awakening", Total Health 32(1), February 2000.
30. IEH Assessment on Phytoestrogens in the Human Diet, Final Report to the Ministry of Agriculture, Fisheries and Food, UK, November 1997, p. 11.
31. Food Labeling: Health Claims: Soy Protein and Coronary Heart Disease, Food and Drug Administration 21 CFR, Part 101 (Docket No. 98P-0683).
32. Sheegan, Daniel M. and Daniel R Doerge, Letter to Dockets Management Branch (HFA-305), February 18, 1999.
33. Anderson, James W. et al., "Meta-analysis of the Effects of Soy Protein Intake on Serum Lipids", New England Journal of Medicine (1995) 333:(5):276-282.
34. Guy, Camille, "Doctors warned against magic, quackery", New Zealand Herald, September 9, 1995, section 8, p. 5.
35. Sander, Kate and Hilary Wilson, "FDA approves new health claim for soy, but litte fallout expected for dairy", Cheese Market News, October 22, 1999, p. 24.
36. Enig, Mary G. and Sally Fallon, "The Oiling of America", NEXUS Magazine, December 1998-January 1999 and February-March 1999; also available at www.WestonAPrice.org.
37. Natural Medicine News (L & H Vitamins, 32-33 47th Avenue, Long Island City, NY 11101), USA, January/February 2000, p. 8.
38. Harras, Angela (ed.), Cancer Rates and Risks, National Institutes of Health, National Cancer Institute, 1996, 4th edition.
39. Searle, Charles E. (ed.), Chemical Carcinogens, ACS Monograph 173, American Chemical Society, Washington, DC, 1976.
40. Nagata, C. et al., Journal of Nutrition (1998) 128:209-213.
41. Campbell, Colin T. et al., The Cornell Project in China.
42. Chang, K.C. (ed.), Food in Chinese Culture: Anthropological and Historical Perspectives, New Haven, 1977.
43. Messina, Mark J. et al., "Soy Intake and Cancer Risk: A Review of the In Vitro and In Vivo Data", Nutrition and Cancer (1994) 21(2):113-131.
44. Rackis et al, "The USDA trypsin inhibitor study", ibid.
45. Petrakis, N.L. et al., "Stimulatory influence of soy protein isolate on breast secretion in pre- and post-menopausal women", Cancer Epid. Bio. Prev. (1996) 5:785-794.
46. Dees, C. et al., "Dietary estrogens stimulate human breast cells to enter the cell cycle", Environmental Health Perspectives (1997) 105(Suppl. 3):633-636.
47. Woodhams, D.J., "Phytoestrogens and parrots: The anatomy of an investigation", Proceedings of the Nutrition Society of New Zealand (1995) 20:22-30.
48. Matrone, G. et al., "Effect of Genistin on Growth and Development of the Male Mouse", Journal of Nutrition (1956) 235-240.
49. Ishizuki, Y. et al., "The effects on the thyroid gland of soybeans administered experimentally in healthy subjects", Nippon Naibunpi Gakkai Zasshi (1991) 767:622-629.
50. Divi, R.L. et al., "Anti-thyroid isoflavones from the soybean", Biochemical Pharmacology (1997) 54:1087-1096.
51. Cassidy, A. et al., "Biological Effects of a Diet of Soy Protein Rich in Isoflavones on the Menstrual Cycle of Premenopausal Women", American Journal of Clinical Nutrition (1994) 60:333-340.
52. Murphy, P.A., "Phytoestrogen Content of Processed Soybean Foods", Food Technology, January 1982, pp. 60-64.
53. Bulletin de L'Office Fédéral de la Santé Publique, no. 28, July 20, 1992.
54. Keung, W.M., "Dietary oestrogenic isoflavones are potent inhibitors of B-hydroxysteroid dehydrogenase of P. testosteronii", Biochemical and Biophysical Research Committee (1995) 215:1137-1144; Makela, S.I. et al., "Estrogen-specific 12 B-hydroxysteroid oxidoreductase type 1 (E.C. 1.1.1.62) as a possible target for the action of phytoestrogens", PSEBM (1995) 208:51-59.
55. Setchell, K.D.R. et al., "Dietary oestrogens - a probable cause of infertility and liver disease in captive cheetahs", Gastroenterology (1987) 93:225-233; Leopald, A.S., "Phytoestrogens: Adverse effects on reproduction in California Quail," Science (1976) 191:98-100; Drane, H.M. et al., "Oestrogenic activity of soya-bean products", Food, Cosmetics and Technology (1980) 18:425-427; Kimura, S. et al., "Development of malignant goiter by defatted soybean with iodine-free diet in rats", Gann. (1976) 67:763-765; Pelissero, C. et al., "Oestrogenic effect of dietary soybean meal on vitellogenesis in cultured Siberian Sturgeon Acipenser baeri", Gen. Comp. End. (1991) 83:447-457; Braden et al., "The oestrogenic activity and metabolism of certain isoflavones in sheep", Australian J. Agricultural Research (1967) 18:335-348.
56. Ginsburg, Jean and Giordana M. Prelevic, "Is there a proven place for phytoestrogens in the menopause?", Climacteric (1999) 2:75-78.
57. Setchell, K.D. et al., "Isoflavone content of infant formulas and the metabolic fate of these early phytoestrogens in early life", American Journal of Clinical Nutrition, December 1998 Supplement, 1453S-1461S.
58. Irvine, C. et al., "The Potential Adverse Effects of Soybean Phytoestrogens in Infant Feeding", New Zealand Medical Journal May 24, 1995, p. 318.
59. Hagger, C. and J. Bachevalier, "Visual habit formation in 3-month-old monkeys (Macaca mulatta): reversal of sex difference following neonatal manipulations of androgen", Behavior and Brain Research (1991) 45:57-63.
60. Ross, R.K. et al., "Effect of in-utero exposure to diethylstilbestrol on age at onset of puberty and on post-pubertal hormone levels in boys", Canadian Medical Association Journal 128(10):1197-8, May 15, 1983.
61. Herman-Giddens, Marcia E. et al., "Secondary Sexual Characteristics and Menses in Young Girls Seen in Office Practice: A Study from the Pediatric Research in Office Settings Network", Pediatrics 99(4):505-512, April 1997.
62. Rachel's Environment & Health Weekly 263, "The Wingspread Statement", Part 1, December 11, 1991; Colborn, Theo, Dianne Dumanoski and John Peterson Myers, Our Stolen Future, Little, Brown & Company, London, 1996.
63. Freni-Titulaer, L.W., "Premature Thelarch in Puerto Rico: A search for environmental factors", American Journal of Diseases of Children 140(12):1263-1267, December 1986.
64. White, Lon, "Association of High Midlife Tofu Consumption with Accelerated Brain Aging", Plenary Session #8: Cognitive Function, The Third International Soy Symposium, November 1999, Program, p. 26.
65. Altonn, Helen, "Too much tofu induces 'brain aging', study shows", Honolulu Star-Bulletin, November 19, 1999.
66. Journal of the American Geriatric Society (1998) 46:816-21.
67. Doerge, Daniel R., "Inactivation of Thyroid Peroxidase by Genistein and Daidzein in Vitro and in Vivo; Mechanism for Anti-Thyroid Activity of Soy", presented at the November 1999 Soy Symposium in Washington, DC, National Center for Toxicological Research, Jefferson, AR 72029, USA.
68. Hughes, Claude, Center for Women's Health and Department of Obstetrics & Gynecology, Cedars-Sinai Medical Center, Los Angeles, CA.
69. Soy Intake May Affect Fetus", Reuters News Service, November 5, 1999.
70. "Vegetarian diet in pregnancy linked to birth defect", BJU International 85:107-113, January 2000.
71. FDA ref 72/104, Report FDABF GRAS - 258.
72. "Evaluation of the Health Aspects of Soy Protein Isolates as Food Ingredients", prepared for FDA by Life Sciences Research Office, Federation of American Societies for Experimental Biology (FASEB) (9650 Rockville Pike, Bethesda, MD 20014, USA), Contract No, FDA 223-75-2004, 1979.

 

©2001 The Healing Crow, Inc.


All rights reserved.
Please direct site commentary or questions to: crow@healingcrow.com

The Healing Crow is a nonprofit corporation. Information published by The Healing Crow is intended to expand the knowledge of the reader about health issues. It is not meant to diagnose, prescribe, or replace medical care. Our mission is to educate the public about chronic illnesses and corresponding non-drug related treatments. We encourage others to critically examine all avenues of information pertaining to health including: naturopaths, chiropractors, physicians, medical and scientific papers, and others; in order to make an informed decision. We believe a patient has the right to question a health source without taking any medical advice on faith. The best patient is an informed one. Before instituting a major change in diet or nutrition please consult a worthy expert in nutrition or a doctor. Although we believe our information to be as accurate as possible, discrepancies may arise. If you have a personal story and would like to include your testimonial on our site, please email us at the link above.



Health

Being Vegan and Eating Soy: Myths, Truths, and Everything in Between
by Christa Novelli, M.P.H.

Soy foods have received a great deal of attention in the media in recent years. Very little that the public hears about soy is neutral. Depending upon whom you choose to believe, soy is either a wonder food or the next asbestos. Even among professionals in the field of nutrition and other sciences, there is much confusion about the conflicting information drawn from the countless research articles published each year on soybeans and their derivatives. While it is unlikely that I will address all concerns or cover every study ever conducted on the health effects of soy consumption, I hope to give a clearer picture of what the research regarding soy and human health tells us.

Article continues below



First, we need to have a basic understanding of what is included in the term “soy foods.” Soy foods encompass a wide variety of items including edamame (whole soybeans), soy flour, soymilk, tofu, soy protein isolates, texturized vegetable protein (TVP), soy oil, and fermented soy products such as tempeh and miso. Adding to this list are all of those processed items that are made from these soy products including soy “meats,” soy cheeses, soy “ice creams,” among many other items. One may be surprised to find out how many foods contain some form of soy (soy flour and soy lethicin are often found in cereals, cake mixes, granola bars, and a whole host of other items). Obviously, vegetarians and vegans are not the only Westerners who eat soy products as a regular part of their diet.

As is often the case when a food or medicine is presented as the new “wonder drug,” soy has experienced a backlash in recent years. A few organizations, most notably the Weston A. Price Foundation (WAPF) and the innocuous sounding Soy Online Service (SOS) in New Zealand, have seized upon any negative studies involving soy products (usually the primary isoflavone found in soy, genestein) and are seeking to have soy foods and formula removed from the public marketplace on the grounds that they cause a myriad of problems ranging from cancers to brain atrophy to immune and endocrine system disorders. As one researcher very accurately noted in his response to an editorial appearing in the professional journal, Leukemia, which has been oft cited as “proof” of soy’s deleterious effects, medical journals are no longer a safe forum for scientists and doctors to discuss and debate new hypotheses with one another. These publications, and in particular the abstracts published in these journals, are increasing being accessed by the public especially in the age of the Internet.

For those of you unfamiliar with scientific writing, an “abstract” is a brief summary of a study’s research question, methods and conclusion(s). Abstracts for many scientific articles can be accessed by the public, free of charge, online at the National Library of Medicine’s website, PubMed and also on Med Line. While I used to be a proponent of “doing your own research,” by searching for information on these websites, the more I have seen about how these abstracts are being used and interpreted the less inclined I am to advise the lay public to draw conclusions from abstracts that can be found on the internet. It is very questionable science to start with your conclusion in mind and then search for any and all studies to support said conclusion. Unfortunately, that is exactly what many of the soy detractors appear to have done, aided by abstracts found online.

A good analogy-- if I started with the conclusion that eating oranges and broccoli was going to cause cancer, I could actually find a number of articles that showed that a component of these foods (vitamin C) has been shown in some trials done on animals and cell cultures to proliferate tumors. I could then publish articles warning of the dangers of oranges and broccoli and cite these studies as “proof.” Of course, I would be going against the much greater body of evidence that shows the exact opposite effect.

Another problem that I have found in looking at the research cited by the detractors of soy is that one can come to a conclusion that is at complete odds with the research you are citing by reading just the abstract of an article. For instance, the WAPF has a link on their website that purports to show the dangers of soy by citing a large number of research studies with direct quotes drawn from the abstracts of these published articles. One example includes a study of soy formula published in the American Journal of Clinical Nutrition in 1998 [1]. On the WAPF site, pieces of the abstract are quoted stating that the researchers found significantly elevated plasma isoflavone levels (plant estrogens found in the blood stream) of infants fed soy-based formula and that this may exert long-term health effects for these infants. What one would find, if he bothered to read the entire article, was that the researchers found health benefits (i.e. – “effects”) for children with increased levels of isoflavones in their blood stream – the exact opposite of what WAPF is attempting to assert.

Similarly, this same site, as well as a number of others such as theomnivore.com and bullz-eye.com, mentions numerous articles that found that soy consumption by males reduces serum (blood) testosterone levels [2] [3] [4]. These studies are cited in online articles with titles like: Soy lives up to its reputation as the breakfast of weenies. WAPF quotes one of the abstracts [3] as testifying that “replacement of meat protein with soyabean protein, as tofu, may have a minor effect on biologically-active sex hormones which could influence prostate cancer risk.” [Emphasis mine] What the term “influence” in the study findings actually meant was reduce, not increase risk. In addressing a similar study [4], WAPF casts doubt on the authors of the study when it questions why they focused on their findings that consuming soy reduced the risk of prostate disease and arteriosclerosis, but failed to note that “testosterone levels fell in the volunteers eating soy but researchers did not stress this alarming finding in their conclusion.” There was no reason for the authors to consider a reduction in testosterone an “alarming finding.” In fact, the reduction in testosterone levels was likely the reason for the reduction in disease risk much the same as reduced estrogen in the blood stream of women reduces breast cancer risk.

So, what does the research show? I will attempt to answer that question by addressing the various health problems that soy has been alleged to prevent and, conversely, cause or exacerbate. Some of the major diseases and health problems that soy has been associated with (in a positive or negative manner) include breast cancer, other cancers, neurodegenerative diseases and dementia (“brain atrophy”), thyroid disorders, infertility, and disorders or problems specific to males (often referred to as “demasculinization”). Then there is the whole separate issue of soy formula, which I will address on its own.



Каталог: Chuong%20Vit
Chuong%20Vit -> On Aug 23, 2013, at 9: 04 pm,: Các Bạn thân mến
Chuong%20Vit -> 3. Ba bốn con vịt bị luột, nhất là con vịt Tây lai vịt đẹt Nga: Bão lạnh nhất Âu Châu từ 100 năm nay sắp tới trong mùa đông nầy
Chuong%20Vit -> Kinh nghiện thực tế về giấm táo pha mật ong
Chuong%20Vit -> Đó là con vịt "death spiral" hay là "new welfare map"
Chuong%20Vit -> Lời bàn Mao Tôn Cương của hcd về chuyện ong chích trị bằng đồng pennies (xu Mỹ)
Chuong%20Vit -> 5. Vịt dặn bà con thế nầy: Đi toilet trên máy bay, đang ngồi, xả nước : RẤT nguy hiểm
Chuong%20Vit -> Bác sĩ giải phẫu xác tín: thiên đàng là có thật
Chuong%20Vit -> From: Truong Giang
Chuong%20Vit -> Hôm nay xin gởi quí bạn con vịt Pháp "ngây thơ", và trả lời vài câu hỏi về computer
Chuong%20Vit -> Sent: Thursday, August 25, 2011 4: 16 pm

tải về 252.53 Kb.

Chia sẻ với bạn bè của bạn:
1   2   3   4   5   6




Cơ sở dữ liệu được bảo vệ bởi bản quyền ©hocday.com 2024
được sử dụng cho việc quản lý

    Quê hương