BEEF CONSUMPTION AND REDUCED SPERM

Consumption of beef by women during pregnancy may alter the uterine testicular development in boys and jeopardize reproductive capacity will be in the future, according to the researchers.
Shanna Swan, Ph.D., and colleagues from the University of Rochester (NY) reported online on March 28, the issue of Human Reproduction.

In a study of 387 pregnant women of fertile couples, men whose mothers reported eating more than seven pieces of beef in a week during pregnancy, have a sperm concentration less than 24% compared with those who ate beef less than that amount, according to findings them. In addition, men who consume lots of beef has tripled sperm concentration included in the classification as sub-fertile according to World Health Organization standards, compared with men whose mothers ate less beef, said Dr. Swan and colleagues.


The reason is the residue of chemicals contained in beef. Although the United States prohibits the development of promoter diethylstilbestrol (DES) is used on calves in 1954, other hormones such as estradiol, testosterone, progesterone and synthetic hormones zerano; trenbolone acetate and melengestrol still in use, according Dr. Swan. While the chemical residue remained after slaughtered.

"The daily intake is acceptable based on the traditional Toxicology tests, and the potential effects of human growth which is open to sex anabolic hormone residues through meat consumption have never done the research, according to Dr. Swan and colleagues. Therefore, he added that "meat consumption by pregnant women and children is of particular concern."

Studies conducted in five cities in the United States between 1999 and 2005 and using the records of the number of mothers of beef they eat. Opposite sperm concentration related to beef consumption by mothers in each week (P = 0041), researchers report.
In boys who consume a lot of beef (more than seven times the beef eaten in a week), sperm concentration of 24.3% lower (P = 0014). The boy who ate lots of beef had an average sperm concentration of 43.1 million sperm / ml semen, while the boys whose mothers ate less beef had an average of 56.9 million sperm.

Comparison of men with sperm concentration below the WHO limit subfertilitas lowest (20 x 106/ml) was three times higher (17.7% to 5.7%. P = 0 / 002) than in men whose mothers consumed less beef. History of previous subfertilitas also common among boys who consume lots of beef (P = 0.015), the researchers reported.

Sperm concentration was not associated with the consumption of other foods made by his mother (pork, lamb, veal) or the consumption of meat in men, according to findings the researchers. Also in women who consume meat chicken, fish, products of nuts and vegetable ingredients seem harmless.

On average, mothers ate 3.4 beef in every week and only 15 (4%) reported eating no beef during pregnancy, while 336 ate beef seven times or less in each week, and 51 reported eating beef more than seven times in each week, according to the researchers. Women who consume a lot of beef eating too much red and more live in North America at the same time the boys they were born by their mothers who consume little meat.

However, the researchers explain that most mothers in this study lived in North America, and this finding does not apply to other areas of the beef produced in other ways.

The researchers also noted that they can not manage confounding that can not be identified related inventions. For example, they say, pesticides, other contaminants in animal food, and lifestyle factors associated with the consumption of beef, enough to play the role of the effect has been observed. They also said heterocyclic amines, produced red meat cold and processes that also produce estrogen.
"Does opening before delivery for anabolic steroids are responsible for our findings in whole or in part, described by repeating this study in people who were born in Europe after 1988 when anabolic steroids no longer be permitted on or beef produced here." The team concluded dr. Swan.