Andersson A M, Skakkebaek N E
University Department of Growth and Reproduction, Rigshospitalet, Copenhagen, Denmark.
Eur J Endocrinol. 1999 Jun;140(6):477-85. doi: 10.1530/eje.0.1400477.
There has been increasing concern about the impact of environmental compounds with hormone-like action on human development and reproductive health over the past decades. An alternative but neglected source of hormone action that may be considered in this connection is hormone residues in meat from husbandry animals treated with sex steroid hormones for growth promotion. Treatment of cattle with naturally occurring or synthetic sex hormones may enhance lean muscle growth and improve feed efficiency and is therefore a very cost effective procedure for cattle producers who have used it for decades in some Western countries, including the USA and Canada. The Joint Food and Agricultural Organisation/World Health Organisation (FAO/WHO) expert committee on food additives (JECFA) and the US Food and Drug Administration (FDA) considered, in 1988, that the residues found in meat from treated animals were safe for the consumers. We have re-evaluated the JECFA conclusions regarding the safety of estradiol residues in meat in the light of recent scientific data, with special emphasis on estradiol levels in prepubertal children. These levels are needed for estimates of the normal daily production rates of estradiol in children, who may be particularly sensitive to low levels of estradiol. In our opinion, the conclusions by JECFA concerning the safety of hormone residues in meat seem to be based on uncertain assumptions and inadequate scientific data. Our concerns can be summarized as follows. 1) The data on residue levels in meat were based on studies performed in the 1970's and 1980's using radioimmunoassay (RIA) methods available at the time. The sensitivity of the methods was generally inadequate to measure precisely the low levels found in animal tissues, and considerable variation between different RIA methods for measuring steroids exists. Therefore the reported residue levels may be subject to considerable uncertainty. 2) Only limited information on the levels of the various metabolites of the steroids was given despite the fact that metabolites also may have biological activity. 3) Reliable data on daily production rates of steroid hormones were and are still lacking in healthy prepubertal children. This lack is crucial as previous guidelines regarding acceptable levels of steroid residues in edible animal tissues have been based on very questionable estimates of production rates in children. Thus, even today the US FDA bases its guidelines on the presumably highly overestimated production rates in prepubertal children given in the JECFA 1988 report. 4) The possible biological significance of very low levels of estradiol is neglected. In conclusion, based on our current knowledge possible adverse effects on human health by consumption of meat from hormone-treated animals cannot be excluded.
在过去几十年里，人们越来越关注具有类激素作用的环境化合物对人类发育和生殖健康的影响。在这方面，一个可能被考虑但却被忽视的激素作用来源是用性类固醇激素处理以促进生长的饲养动物肉中的激素残留。用天然或合成性激素处理牛可以促进瘦肉生长并提高饲料效率，因此对于一些西方国家（包括美国和加拿大）已经使用了几十年的养牛生产者来说，这是一个非常经济有效的方法。1988年，联合国粮食及农业组织/世界卫生组织（粮农组织/世卫组织）食品添加剂联合专家委员会（JECFA）和美国食品药品监督管理局（FDA）认为，在经处理动物的肉中发现的残留物对消费者是安全的。我们根据最近的科学数据，重新评估了JECFA关于肉类中雌二醇残留安全性的结论，特别强调了青春期前儿童体内的雌二醇水平。这些水平对于估计儿童体内雌二醇的正常日产量是必要的，因为儿童可能对低水平的雌二醇特别敏感。我们认为，JECFA关于肉类中激素残留安全性的结论似乎基于不确定假设和不充分的科学数据。我们的担忧可总结如下：1）肉类中残留水平的数据基于20世纪70年代和80年代使用当时可用的放射免疫分析（RIA）方法进行的研究。这些方法的灵敏度通常不足以精确测量动物组织中发现的低水平，并且不同RIA方法测量类固醇之间存在相当大的差异。因此，报告的残留水平可能存在相当大的不确定性。2）尽管代谢物也可能具有生物活性，但关于类固醇各种代谢物水平的信息有限。3）健康青春期前儿童类固醇激素日产量的可靠数据过去缺乏，现在仍然缺乏。这一缺失至关重要，因为之前关于可食用动物组织中类固醇残留可接受水平的指导方针是基于对儿童产量非常可疑的估计。因此，即使在今天，美国FDA的指导方针仍然基于JECFA 1988年报告中可能被高估的青春期前儿童产量。4）极低水平雌二醇的可能生物学意义被忽视。总之，根据我们目前的知识，不能排除食用经激素处理动物的肉对人类健康可能产生的不利影响。
