Bruce Bonnie, Messina Mark, Spiller Gene A
Division of Immunology and Rheumatology, Department of Medicine, Stanford University, Palo Alto, CA 94304, USA.
J Med Food. 2003 Winter;6(4):309-16. doi: 10.1089/109662003772519859.
Despite the safety review conducted by the U.S. Food and Drug Administration in the process of awarding a health claim for the cholesterol-lowering properties of soy protein, concerns about the possible goitrogenic effects of soybean isoflavones persist. Concerns are based primarily on in vitro research, animal studies, and older reports of goiter in infants fed soy formula not fortified with iodine. In a randomized, double blind, placebo-controlled study, we investigated the effect on thyroid function of a daily supplement containing 90 mg (aglycone weight) of total isoflavones/day versus placebo in 38 postmenopausal women, 64-83 years old, not on hormone replacement therapy. Serum thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3) were measured at baseline and after 90 and 180 days. In the supplement group, at baseline and 6 months, TSH (micro U/ml), T4 (nM), and T3 (nM) levels (mean +/- SE) were 3.00 +/- 0.44, 149.00 +/- 5.04, and 1.53 +/- 0.13, respectively, and 3.49 +/- 0.52, 154.52 +/- 2.09, and 1.78 +/- 0.12, respectively. In the control group, levels at baseline and at 6 months were 3.35 +/- 0.51, 145.39 +/- 6.69, and 1.55 +/- 0.18, respectively, and 3.63 +/- 0.57, 153.77 +/- 6.64, and 1.75 +/- 0.10, respectively. Intragroup differences for all three measures were statistically indistinguishable at 6 months, and levels were similar between the isoflavone supplement and placebo groups at each measurement. These results indicate that in this group of healthy iodine-replete subjects, soy isoflavones do not adversely affect thyroid function.
尽管美国食品药品监督管理局在批准大豆蛋白降胆固醇特性的健康声明过程中进行了安全性审查，但对大豆异黄酮可能产生的致甲状腺肿作用的担忧依然存在。这些担忧主要基于体外研究、动物研究以及关于食用未添加碘的大豆配方奶粉的婴儿甲状腺肿的早期报告。在一项随机、双盲、安慰剂对照研究中，我们调查了每日补充含90毫克（苷元重量）总异黄酮与安慰剂对38名年龄在64至83岁、未接受激素替代疗法的绝经后女性甲状腺功能的影响。在基线以及90天和180天后测量血清促甲状腺激素（TSH）、甲状腺素（T4）和三碘甲状腺原氨酸（T3）。在补充剂组中，基线和6个月时，TSH（微单位/毫升）、T4（纳摩尔）和T3（纳摩尔）水平（均值±标准误）分别为3.00±0.44、149.00±5.04和1.53±0.13，以及3.49±0.52、154.52±2.09和1.78±0.12。在对照组中，基线和6个月时的水平分别为3.35±0.51、145.39±6.69和1.55±0.18，以及3.63±0.57、153.77±6.64和1.75±0.10。6个月时，所有三项指标的组内差异在统计学上无显著差异，且每次测量时异黄酮补充剂组和安慰剂组的水平相似。这些结果表明，在这组碘充足的健康受试者中，大豆异黄酮不会对甲状腺功能产生不利影响。
