Exposure to growth hormones in beef could be putting Americans at risk for infertility. A recent study found that women who routinely ate beef were far more likely to give birth to boys who grow up to have lower-than-normal sperm counts. Yet despite the fact that infertility might be linked to the use of growth hormones in beef, these dangerous drugs are used by the cattle industry at an alarming rate in the U.S.
Conventional livestock producers have been administering growth hormones to beef cattle since the 1950s. More than half a century later, six anabolic steroids-three natural and three synthetic-are given, in a variety of combinations, to nearly all animals in conventional feedlots in the U.S. and Canada. The three natural steroids used are estradiol, testosterone, and progesterone and the three synthetic hormones used are the estrogen compound, zeranol; the androgen, trenbolone acetate; and progestin melengestrol acetate. The steroids are typically used in combinations. Measurable levels of all of these growth-promoting hormones are found in the muscle, fat, liver, kidneys, and other organ meats we routinely eat at meal time, yet questions and controversy over the impacts of these added hormones on human development and health have lingered for four decades and remain unexamined and unanswered.
In 1988, the European Union banned the use of all hormone growth promoters; however, the U.S. Food and Drug Administration (FDA) has set Acceptable Daily Intakes (ADIs) for these animal drugs. ADIs are based on traditional toxicity testing methods and do not reflect the capacity of these drugs, which are potent endocrine disruptors, to alter fetal and childhood development. The possible effects on humans exposed to residues of anabolic sex hormones through meat consumption have never been studied; however, it is recognized and accepted that the fetus and the pre-pubertal child are particularly sensitive to exposure to sex steroids. Unbelievable, given that every beef-eating person for over 50 years has been exposed to these hormones on a regular basis.
The lack of data on the safety of human consumption of anabolic steroids in meat prompted analysis via a large, multi-center pregnancy cohort study-the-Study for Future Families (SFF)-comparing pregnant women’s beef consumption relative to their sons semen parameters. Researchers divided pregnant women into two groups: A high beef consumption group of women who consumed more than seven beef meals per week and a low beef consumption group who consumed fewer than seven beef meals per week. Once the male babies were born and reached a stage where they produced sperm, researchers compared sperm concentrations and quality to men born to women in the high and low beef consumption groups. Of the 773 men who provided semen samples, 387 were from mothers from the high beef consumption group, and 386 were from mothers from the low beef consumption group. Research revealed that sperm volume was 24.3 percent higher in the sons of mothers in the low beef consumption group, nearly 18 percent of the sons born to women in the high beef consumption group had sperm concentrations even below the World Health Organization threshold for sub fertility-about three-times more the sons of women in the low consumption group.
Authors of the study concluded that the 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, lending credence and urgency to the long-recognized need for the FDA to reconsider growth hormone ADIs in beef.