Beef Hormones Affect Fertility

One stated reason for US beef to have been forbidden in some countries.

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Study: Beef Hormones Affect Fertility
Research

05:27 PM, March 28th 2007
by Moni Constantinescu


Pregnant women eating beef from cattle treated with growth-promoting
hormones could well endanger their children¹s future fertility.

According to new research, men from the US whose mothers ate beef at least
once a day during pregnancy are likely to have lower sperm concentrations
than usual, potentially affecting their ability to have children.

This could be due to anabolic steroids and other hormones widely given to
American cattle to promote growth, which might have side-effects on the
sexual development of unborn male fetuses. It could also be due to
pesticides and other environmental contaminants.

Professor Shanna Swan, of the University of Rochester in New York state,
who led the study, cautioned that this was applicable only to men from North
America born between 1949 and 1983. More research was needed to confirm or
refute the hypothesis, she said.

Professor Swan said that the research pointed towards growth-promoting
hormones in beef as a likely cause of the men¹s lower fertility. ³These
findings suggest that maternal beef consumption is associated with lower
sperm concentration and possible sub-fertility * associations that may be
related to the presence of anabolic steroids and other xenobiotics in beef,²
she said.

Professor Swan¹s team analyzed the semen of 387 men living in the US who
were born between 1949 and 1983. On average, the mothers of the men reported
eating 4.3 beef meals per week while they were pregnant, but 51 ate beef
seven or more times each week.

These women were also more likely to eat large amounts of other red meat,
and to have been living in the US when they gave birth. The sperm counts of
men born to this group of heavy beef eaters were on average 24 per cent
lower than those of men born to mothers with normal diets.***

17.7 per cent of these men had sperm counts that are classified as
sub-fertile according to World Health Organization guidelines, though this
amounted to just nine individuals. The sub-fertility rate among men born to
mothers who consumed less beef was 5.7 per cent.

If the sperm deficit is related to the hormones in beef, Swan's findings
may be ³just the tip of the iceberg,² wrote biologist Frederick vom Saal of
the University of Missouri in an editorial accompanying the paper. The study
is published in the journal Human Reproduction.

Six growth-promoting hormones are routinely used in cattle production in
the United States and Canada: the natural steroids estradiol, testosterone
and progesterone, and the synthetic hormones zeranol, trenbolone acetate and
melengestrol acetate. At slaughter, not all of these hormones have been
metabolized.

"Earl Evleth" a écrit dans le message de news:
...
One stated reason for US beef to have been forbidden in some countries.

*****



Study: Beef Hormones Affect Fertility
Research

05:27 PM, March 28th 2007
by Moni Constantinescu


Pregnant women eating beef from cattle treated with growth-promoting
hormones could well endanger their children¹s future fertility.

According to new research, men from the US whose mothers ate beef at least
once a day during pregnancy are likely to have lower sperm concentrations
than usual, potentially affecting their ability to have children.

This could be due to anabolic steroids and other hormones widely given to
American cattle to promote growth, which might have side-effects on the
sexual development of unborn male fetuses. It could also be due to
pesticides and other environmental contaminants.

Professor Shanna Swan, of the University of Rochester in New York state,
who led the study, cautioned that this was applicable only to men from
North
America born between 1949 and 1983. More research was needed to confirm or
refute the hypothesis, she said.

Professor Swan said that the research pointed towards growth-promoting
hormones in beef as a likely cause of the men¹s lower fertility. ³These
findings suggest that maternal beef consumption is associated with lower
sperm concentration and possible sub-fertility * associations that may be
related to the presence of anabolic steroids and other xenobiotics in
beef,²
she said.

Professor Swan¹s team analyzed the semen of 387 men living in the US who
were born between 1949 and 1983. On average, the mothers of the men
reported
eating 4.3 beef meals per week while they were pregnant, but 51 ate beef
seven or more times each week.

These women were also more likely to eat large amounts of other red meat,
and to have been living in the US when they gave birth. The sperm counts
of
men born to this group of heavy beef eaters were on average 24 per cent
lower than those of men born to mothers with normal diets.

17.7 per cent of these men had sperm counts that are classified as
sub-fertile according to World Health Organization guidelines, though this
amounted to just nine individuals. The sub-fertility rate among men born
to
mothers who consumed less beef was 5.7 per cent.

If the sperm deficit is related to the hormones in beef, Swan's findings
may be ³just the tip of the iceberg,² wrote biologist Frederick vom Saal
of
the University of Missouri in an editorial accompanying the paper. The
study
is published in the journal Human Reproduction.

Six growth-promoting hormones are routinely used in cattle production in
the United States and Canada: the natural steroids estradiol, testosterone
and progesterone, and the synthetic hormones zeranol, trenbolone acetate
and
melengestrol acetate. At slaughter, not all of these hormones have been
metabolized.