The Telegraph (UK), March 28, 2007

DON'T MESS WITH HORMONES, EXPERT WARNS

[Rachel's introduction: A new report on men in the U.S. finds low sperm counts correlate with eating beef, and a well-known British scientist advises a precautionary approach to hormone-treated meat.]

By Roger Highfield, Science Editor

The relevance of this work to the UK is open to question, according to Professor Richard Sharpe of the Medical Research Council's Human Reproductive Sciences Unit in Edinburgh.

"I don't think that in Europe we ever used these chemicals to quite such the same extent as in the United States," he said.

However, Prof Sharpe said there was no doubt that sperm counts in young men across Europe "are very low on average".

Although there is no clear explanation, he said there was mounting evidence "that if you mess around with hormones of the male baby in the womb there are going to be consequences, one of which is to affect sperm counts and fertility".

But to prove a single chemical is responsible is "an impossible task," Prof Sharpe added.

The latest studies from Europe and America show that mixtures of hormone-like chemicals, each of which is at levels thought to have no effect, can have significant effects when they act in concert.

"Individual chemicals are probably not to blame while mixtures are almost certain to have some effect," Prof Sharpe said.

Over the years, growth promoters used in America have changed from those with a female hormone-like action to having a male action, he said.

In Europe, the use of these hormones has been banned since 1988 and there has been an EU-wide ban of US beef.

Prof Sharpe said today's news "will be music to the EU's ears because of its fight with the US on embargoing imports of their meat".

Growth promoters for cattle, such as the synthetic hormone diethylstilbestrol (DES), have been used in the USA since 1954.

Although DES was banned for use in cattle in 1979, other hormones such as oestradiol, testosterone, progesterone, zeranol, trenbolone acetate and melengestrol continue to be used.

Residues of these chemicals remain in the meat after slaughter, so American authorities have regulated their use to avoid unintended adverse effects in humans eating the meat and defined an "acceptable daily intake".

Acceptable intakes are, however, based on traditional toxicological testing "and the possible effects on human populations exposed to residues of anabolic sex hormones through meat consumption have never, to our knowledge, been studied," said Prof Shanna Swan, author of the new work.

Copyright Copyright of Telegraph Media Group Limited 2007