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Re:【medical-news】大豆雌激素与乳癌

Soy Estrogens And Breast Cancer: Researcher Offers Overview
21 May 2007
大豆雌激素与乳癌
Are soy products healthy additions to a person's diet, safe alternatives to hormone-replacement therapy or cancer-causing agents" The answer, according to University of Illinois food science and human nutrition professor William Helferich, is, "It depends."
豆制品是人们饮食的健康添加剂吗?是激素替代疗法的另外安全选择吗?还是致癌物质?按照伊利诺斯大学食品科学和人类营养学教授William Helferich的观点,答案是“视情况而定。”
He reviews the science linking breast cancer, soy and dietary supplements that contain soy phytoestrogens this month at a conference on "Diet and Optimum Health" sponsored by the Linus Pauling Institute at Oregon State University.
他在本月由俄勒冈州立大学莱纳斯鲍林研究所主办的“饮食与最适健康”会议上,综述了有关乳癌、大豆和含大豆植物雌激素的食品添加剂的科学研究。
Helferich has spent a decade evaluating the health effects of isoflavones, a class of plant estrogens present in high concentrations in soy. Much of his work has focused on a single isoflavone, genistein, which occurs in varying concentrations in soy products or ingredients such as tofu, soy protein isolates, soy flour and some estrogenic dietary supplements.
Helferich十年来一直从事有关异黄酮对健康影响的评价研究。异黄酮是一类植物雌激素,在大豆中含量丰富。他的大部分工作集中于一种异黄酮——染料木素的研究,染料木素在豆制品,诸如豆腐、大豆蛋白分离物、大豆粉以及一些雌激素食品添加剂等,含量变化很大。
Genistein is of interest because it is the most active of the soy isoflavones, and because it activates estrogen receptors in cells, including some breast tumor cells.
染料木素之所以引起人们的关注,是因为它是大豆异黄酮的最具活性的成分,它可活化细胞的雌激素受体,这些细胞包括某些乳癌细胞。
Dozens of studies of the role of human and plant estrogens in breast cancer have yielded seemingly contradictory findings. Some found that feeding genistein to female rats prior to puberty reduced the number of chemically induced mammary tumors. Other studies showed that estradiol, a primary human estrogen, spurs the growth of existing estrogen-dependent breast tumors.
许多有关人和植物雌激素对乳癌影响的研究结果表面上看似相互矛盾。有些研究发现,雌性大鼠青春期前喂养染料木素可减少化学方法诱导的乳腺肿瘤数量;另外研究显示,人主要雌激素——雌二醇可促进已有雌激素依赖的乳腺中的增长。
Helferich and colleagues demonstrated that - like estradiol - dietary genistein stimulates the growth of estrogen-responsive tumors. They also found that dietary genistein interferes with treatments, such as tamoxifen, that target estrogen receptors in breast tumors. (About 70 percent of women with breast cancer have estrogen-responsive tumors.)
Helferich及其同事证明,如同雌二醇,饮食中的染料木素刺激雌激素敏感肿瘤的生长。他们还发现,饮食中的染料木素还干扰某些药物的治疗,如他莫昔芬,它作用于乳腺肿瘤的雌激素受体。(约70%的乳癌妇女具有雌激素依赖性肿瘤。)
"The resolution of this paradox may lie in the timing of estrogen administration," Helferich said. Exposure to genistein, an estrogen, before puberty causes mammary gland differentiation. "A differentiated cell undergoes less proliferation and therefore is less likely to progress through the cancer process," he said. "However, if the estrogen is administered to an animal after the development of an estrogen-responsive tumor, the growth of this tumor will be stimulated," he said.
“对这一自相矛盾结果的解释取决于雌激素的服用时间,” Helferich说道。青春期前服用雌激素染料木素可导致乳腺分化,“分化的细胞很少增殖,因而很少发生癌变;然而,如果已经患有雌激素反应肿瘤的动物服用雌激素,则刺激肿瘤的生长。”
Today Helferich is most concerned about the use of genistein and other isoflavones in supplements sold as "natural" alternatives to hormone-replacement therapy. He notes that midlife women who consume these products perceive them as natural and safe. But women aged 50 and older are also most at risk of developing breast cancer. Helferich is evaluating the biological activity of some of these products, which are available in many forms, do not require a prescription, and in most cases are consumed without the knowledge of their physicians.
在今天的报告中,Helferich最为关注的是染料木素和食品添加剂中其它异黄酮的应用问题,这些添加剂作为激素替代疗法的“天然”替代品而出售。他指出,中年妇女食用这些产品是适合的和安全的,但50岁或50岁以上妇女则冒患乳癌的风险。Helferich正在从事对某些这类产品生物活性的评价工作,这些产品以多种形式出售,不需要处方,并且在大多数情况下服用者的医生并不知情。
Helferich notes that the incidence rate of breast cancer in women aged 50 and over in the U.S. dropped significantly after use of hormone-replacement therapy (HRT) declined in 2002 and 2003. While purified genistein is not as potent as HRT, Helferich said, it still poses a risk to midlife women because the amount consumed is much higher. The labels of many products that contain this and other isoflavones lack vital information about what is actually in their products, he said, and because these are natural products, the consistency from batch to batch is difficult to control.
Helferich指出, 2003年和2003年由于激素替代疗法应用的减少,50岁及以上的美国妇女乳癌发病率显著下降。虽然纯化的染料木素的作用没有激素替代疗法大,但由于用量较大,所以对中年妇女仍具有一定的风险。许多含有这样或那样异黄酮的产品标签中缺少有关真实成分的信息,由于它们属于天然产品,批次间含量难以控制。
"Women are participating in an ongoing experiment with an unknown outcome," he said. "You can't identify what dose of isoflavones you're getting."
“妇女正在参与一项结果未知的试验,异黄酮的摄入量不能确定。”他说。
But genistein is only one component of soy, Helferich said, and studying its effects in purified form may lead to misleading conclusions about the health consequences of soy in the diet. In fact, studies have shown that foods like soy flour have a very different effect.
Helferich称,由于染料木素仅仅是大豆成分之一,对纯化的染料木素的研究可能会导致对饮食中大豆的健康意义的误解。事实上,业已证实像大豆粉之类的食物具有非常不同的作用。
"The complex mixture found in soy flour doesn't make the tumor grow," Helferich said.
“大豆粉中复杂的混合成分并不促进肿瘤生长,”他说道。
"Whole soy contains a lot of biologically active ingredients, but together they may have multiple effects that can reduce the negative outcomes. When the whole food is consumed you get a very different effect than if you consume the concentrated constituents individually."
“大豆含有多种生物活性成分,它们合在一起具有多种作用,可降低负面效果。食用全豆类食品与单独服用每种浓缩成分相比,所产生的作用大为不同。
All this research points to a very simple truth, Helferich said: The whole soybean is healthier than many of its individual chemical parts.
所有研究归结于一条简单事实,Helferich称,全大豆比其许多单一的化学成分更有助于健康。
"That raw food can be consumed for less than a dollar a serving and is likely better for you than that thing you pick up at the health food store for $30 a pound," he said.
“食用每份不到1美元的未加工大豆,比从健康食品商店花费30美元购买的食品,可能更有利于你的健康。”他最后说道。
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大豆雌激素与乳癌

据《今日健康新闻》5月21日报道,伊利诺斯大学食品科学和人类营养学教授William Helferich在本月由俄勒冈州立大学莱纳斯鲍林研究所主办的“饮食与最适健康”会议上,综述了有关乳癌、大豆和含大豆植物雌激素的食品添加剂的科学研究后指出,豆制品是否是健康的食品添加剂、是否可以安全替代激素替代疗法、是否是致癌物质,这要“视情况而定。”
Helferich十年来一直从事有关异黄酮对健康影响的评价研究。异黄酮是一类植物雌激素,在大豆中含量丰富。他的大部分工作集中于一种异黄酮——染料木素的研究,染料木素在豆制品,诸如豆腐、大豆蛋白分离物、大豆粉以及一些雌激素食品添加剂等,含量变化很大。染料木素之所以引起人们的关注,是因为它是大豆异黄酮的最具活性的成分,它可活化细胞的雌激素受体,这些细胞包括某些乳癌细胞。
许多有关人和植物雌激素对乳癌影响的研究结果表面上看似相互矛盾。有些研究发现,雌性大鼠青春期前喂养染料木素可减少化学方法诱导的乳腺肿瘤数量;另外研究显示,人主要雌激素——雌二醇可促进已有雌激素依赖的乳腺中的增长。
Helferich及其同事证明,如同雌二醇,饮食中的染料木素刺激雌激素敏感肿瘤的生长。他们还发现,饮食中的染料木素还干扰作用于乳腺肿瘤雌激素受体的某些药物的治疗,如他莫昔芬。Helferich指出,对这一自相矛盾结果的解释取决于雌激素的服用时间。青春期前服用雌激素染料木素可导致乳腺分化,如果已经患有雌激素反应肿瘤的动物服用雌激素,则刺激肿瘤的生长。
在今天的报告中,Helferich最为关注的是染料木素和食品添加剂中其它异黄酮的应用问题,这些添加剂作为激素替代疗法的“天然”替代品而出售。他指出,中年妇女食用这些产品是适合的和安全的,但50岁或50岁以上妇女则冒患乳癌的风险Helferich指出, 2003年和2003年由于激素替代疗法应用的减少,50岁及以上的美国妇女乳癌发病率显著下降。虽然纯化的染料木素的作用没有激素替代疗法大,但由于用量较大,所以对中年妇女仍具有一定的风险。许多含有这样或那样异黄酮的产品标签中缺少有关真实成分的信息,由于它们属于天然产品,批次间含量也难以控制。
Helferich称,由于染料木素仅仅是大豆成分之一,仅仅对纯化的染料木素的研究可能会导致对饮食中大豆的健康意义的误解。事实上,业已证实像大豆粉之类的食物具有非常不同的作用,大豆粉中复杂的混合成分并不促进肿瘤生长。大豆含有多种生物活性成分,它们合在一起具有多种作用,可降低某写成分的负面效果。食用全豆类食品与单独服用每种浓缩成分相比,所产生的作用大为不同。
Helferich称,食用每份不到1美元的未加工大豆,比从健康食品商店花费30美元购买的食品,可能更有利于你的健康。他最后指出,所有研究归结于一条简单事实,即全大豆比其许多单一的化学成分更有助于健康。
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