The use of growth-promoting hormones in the large scale dairy industry has become well known. However, the use of hormones in beef cattle is even more common than with dairy cattle. Growth-promoting hormones are used in nearly all large commercial feedlots in the U.S. and 90% of their cattle receive them. Nearly 30 growth-promoters are marketed in the U.S. for use in animals. The U.S. FDA and U.S.D.A believe that the use of growth hormones is safe when utilized according to good veterinary practices. However, scientists have acknowledged that long-term population studies have not been established concerning the effects of hormones in food-producing animals. The American Cancer Society reports studies linking growth hormones to tumor development in breast, prostate, non-small cell lung and advanced colorectal cancers.
The European Union banned the production and importation of meat associated with growth promoters beginning in the 1980s, including the restriction of meat trade from countries known to routinely use growth promoters. Only recently has the European Union modified the ban on U.S. imports to include a limited amount of meat certified as hormone free through a joint USDA and European Union program. The European Union stands behind the claim that growth hormones given to beef cattle pose a risk to consumers. Specifically, the EU believes that growth hormones pose developmental, immunological, neurobiological, immunotoxic, genotoxic, and carcinogenic effects. No threshold currently exists for what levels of ingested hormone treated meats are safe.
Why are hormones used in beef cattle? A major use of growth hormones is to enhance the growth of the cattle quickly without the need for additional feed. Hence, growth promoters are a way to reduce production costs. An alternative benefit of the use of hormones in beef cattle is to mask the markers of stress to the consumer. Properly timed hormone administration reduces the occurrence of dark cutting beef - the purplish black appearance in meat that indicates long-term stress. Growth hormones help to maintain muscle pH during stress, which leads to the more desirable ruby red appearance of meat showcased in supermarket shelves.