Print

Mail

wiki links

Hormone-treated beef tied to sperm woes

Hormone-treated beef may be linked to low sperm counts and borderline fertility among US men, according to a first-ever study which appeared in a medical journal yesterday.

The paper says men whose mothers were big eaters of beef -- most of which is treated with hormones in the US to accelerate cattle growth -- have lower fertility levels compared with counterparts whose mothers ate less or no beef.

It is the first peer-assessed investigation into the effect of food on the human reproductive system, its authors believe.

US farmers have been using hormones to promote muscle growth in cattle for more than half a century.

The EU outlawed the substances in 1988 on health grounds, triggering a huge trade row with the US. The WTO is to issue a technical ruling on the dispute on April 17, a European Commission source said.

The study looked at 387 US men born between 1949 and 1983 who were interviewed about their childhood background and their history of fertility and were asked to give a sperm sample.

Sons of women who ate more than seven beef meals a week had a sperm count that was nearly 25 percent lower than men whose mothers ate less beef. And they were nearly three times likelier to have sperm concentrations that fell below the WHO threshold of sub-fertility.

The more beef the mother ate, the lower the son's sperm quality.

"These data suggest that maternal beef consumption, and possibly xenobiotics [foreign chemicals] in beef, may alter a man's testicular development in utero and adversely affect his reproductive capacity," the study says.

The paper appears in Human Reproduction, the journal of the European Society of Human Reproduction and Embryology.

"When you disrupt hormones pre-natally, you affect a whole cascade, and in particular, oestrogens and androgens affect testicular development," said lead author Shanna Swan, a professor at the department of obstetrics and gynecology at the University of Rochester, New York

The "plausible hypothesis," which is also supported by previous work on lab rodents, is that hormones are the cause, Swan said. She stressed, though, that this was not a definitive conclusion and that further work, such as assessing the fertility of European men born after 1988, was needed.

"Together with animal data, it suggests there is a large potential for concern here. I don't think we can assume that these products are risk-free," she said.

The first synthetic hormone, diethylstilbestrol, or DES, was formulated in 1933. In 1947, it was approved for use by pregnant women to prevent miscarriages.

The US Food and Drug Administration (FDA) approved DES for accelerating muscle growth in cattle in 1954.. By 1956, more than two-thirds of US feeder cattle were receiving DES, according to Swan's study.

In 1979, the FDA withdrew use of DES for cattle, eight years after it was banned for use by pregnant women following evidence that it damaged male and female reproductive systems.

In a preliminary reaction, the US Meat Export Federation complained that the study did not identify mothers who had been taking DES as a medication.

"It's quite possible that this study is actually showing results of pre-natal exposure to DES through oral supplementation to the mother, not through beef," the federation's export services manager, Courtney Heller, said in an e-mail.
This story has been viewed 1252 times.