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Question of the Week:  Do Hormones and Antibiotics Cause Health Problems in Humans?


I often receive questions about the therapeutic feeding of antibiotics to calves with pneumonia as well as the implanting of steers to improve growth rate.  The following information is provided to help increase the understanding of these two issues.

Myth: The use of antibiotics and hormone growth implants in livestock production is causing hazardous residues in beef and contributing to the development of health problems in humans.


  1. No residues from feeding antibiotics are found in beef, and there is no valid scientific evidence that antibiotic use in cattle causes illness resulting from the development of antibiotic-resistant bacteria.

  2. Scientific authorities agree that use of hormone implants results in the efficient production of beef that is safe.


Background: Some say that low-level, continuous feeding of penicillin  and tetracyclines to livestock and poultry for growth promotion may result in development of antibiotic resistant bacteria and thus contribute to human illness. The National Academy of Sciences says it has never found data directly implicating subtherapeutic use of feed microbials as a risk factor in human illness.

Penicillin is not fed to cattle. For several years, there has been little subtherapeutic feeding of tetracyclines to cattle, even though such use continues to be approved as safe. There is no valid scientific evidence that feeding antibiotics to beef cattle causes human health problems. A recent report by USDA's Food Safety and Inspection Service showed no antibiotic residue problems with beef cattle.

Whether or not antibiotics are used in animals, resistant organisms will exist. But all are sensitive to heat, and proper cooking will kill all disease-causing bacteria that may be found in beef products.


Hormones are naturally present in infinitesimal amounts in all meat, whether from implanted animals or not. The amount of estrogen in plant-source foods is larger than in meat. The human body produces hormones in quantities much greater than would ever be consumed by eating beef or other foods. Hormones in beef from implanted steers have no physiological significance for humans whatsoever. The estrogen level in a 3-oz. serving of beef from an implanted steer is 1.85 nanograms (a nanogram is a billionth of a gram); the level in the same
size portion of beef from a non-implanted steer is 1.3 nanograms. By comparison, a non-pregnant woman produces 480,000 nanograms of estrogen daily.

Hormone implants also increase the efficiency of beef production, thus alleviating energy, feed usage and environmental impacts, and improve overall quality and healthfulness of beef by reducing the amount of fat.  The increased efficiency  implants offer saves U.S. families hundreds of dollars  each year by lowering  the cost of retail beef by 20 cents to 30 cents per pound [IVD50 - 49].

Cattle producers continue to be actively involved in assuring that beef products are safe and wholesome for consumers. Forty-one states  have industry-initiated beef quality assurance programs that educate producers on the production of safe and healthful beef  products and prevention of hazardous residues.  Participating states account for 98% of the nation's feedlot cattle and 95% of the country's breeding cows. [BB, 3.5 - 50].


  • Antibiotics for Animals: The Antibiotic Resistance Issue, Council for Agricultural Science and Technology, 1989.
  • Chemicals in the Meat Supply -- a Review, F.M. Byers, Texas A&M University, 1990.
    Expert Committee on Additives, Food and Agricultural Organization/World Health Organization, 1987.
  • Food News for Consumers, Food Safety and Inspection Service, Winter 1990. 49 - Food Safety in the Beef Cattle Industry, Harlan D. Ritchie,     Michigan State University, proceedings, The LaCosta Conference on   "Cattle on the Land: Environmental Implications of Beef Production, 1990.
  • Report on Regulatory Program for Drug and Pesticide Residues in Meat and Poultry, 1989, Richard L. Carnevale, Food Safety and Inspection Service, 1990.
  • Report on Use of Hormonal Substances in Animals, Inter-American  Institute for Cooperation on Agriculture, 1986.
  • Subtherapeutic Use of Antibiotics in Fed Animals Reviewed, Food & Drug Administration, 1989.


Source of this article: http://beef.org/library/myths_facts/archive/myth_11.htm


There is no valid scientific evidence that feeding antibiotics to beef cattle causes human health problems.


Understanding the Beef Consumer - January, 2001

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