Hormone-free foods

The phrases “hormone free” or “no hormones” are used to describe beef or milk that has been produced without the use of additional natural or synthetic sex steroids or protein growth hormones. The use of these phrases in food labeling is regulated by the U.S. Department of Agriculture (USDA) in the United States and by Health Canada in Canada. Some controversy surrounds the use of hormones in animal husbandry, primarily in regard to possible side effects of these drugs on humans and the environment and also whether or not certain types of food labeling and advertising are intended to influence consumer choice.

There are several reasons for using hormones in beef and milk production, including to:

The major reasons for not using hormones in beef or milk production are international trade and consumer preference. The European Union (EU) began to ban beef produced from hormone-treated cattle in 1988, but the United States and Canada opposed the ban and raised duties on EU imports. In 2012, an agreement was reached, with the EU agreeing to import quotas of untreated beef from Canada and the United States.

In the case of milk, consumer concerns about the possible side effects of milk produced from cows treated with rbST has led to a controversy about the use of “hormone free” in milk labeling. Some dairy farmers maintain that the use of “hormone free” or “no hormones” labeling is a scare tactic intended to influence consumers to choose some brands of milk over others. A study carried out by the Academy of Nutrition and Dietetics (formerly the American Dietetic Association) in 2008 reported that “[milk] label claims were not related to any meaningful differences in the milk compositional variables measured.”

The use of “hormone free” is somewhat of a misnomer, as the milk and other body tissues of all mammals contain hormones. For example, the production of human breast milk requires the interaction of at least six different hormones, some of which are passed on in the mother's milk to the nursing infant. The same is true of lactating dogs, cats, mice, goats, and sheep. Similarly, the meat from cattle raised for beef production contains small amounts of sex hormones. Some researchers prefer the terms endogenous and exogenous to distinguish the two types of hormones; endogenous hormones are produced inside the animal's body, and exogenous hormones are administered from the outside.

The use of exogenous hormones in beef production dates back to the late 1930s, and it was practiced in over 20 countries until the EU ban of 1988. There are six steroid hormones used to increase muscle tissue in beef cattle—three naturally occurring chemicals (estradiol, progesterone, and testosterone), and three synthetic (melengestrol acetate, trenbolone acetate, and zeranol). These hormones are administered to cattle either in their feed or through implants (pellets) inserted under the skin of the ear. The animal's ear is removed at the time of slaughter to prevent the implant from entering the human food supply.

Posilac is a protein hormone rather than a steroid hormone. Posilac is given by injection about 60 days into a cow's lactation period. Cows usually begin their lactation period with only a moderate rate of lactation, with the rate rising until it reaches a peak about 70 days after the start of lactation. It then declines gradually until the cow is dry. The rise and fall in milk production levels are related in part to the number of milk-producing cells in the cow's udder. These cells are gradually lost during the phase of decline in lactation and do not regrow until the cow's next lactation period. Posilac works by sustaining the number of milk-producing cells in the udder, which is the reason for its being given shortly before the cow's milk production reaches its peak. The hormone is sold in packages of single-dose injections to reduce the risk of accidental overdose.

The USDA specifies that foods cannot be labeled as hormone free if they are produced from animals that cannot be legally treated with hormones—primarily pork and poultry. The USDA states, “Hormones are not allowed in raising hogs or poultry. Therefore, the claim ‘no hormones added’ cannot be used on the labels of pork or poultry unless it is followed by a statement that says ‘federal regulations prohibit the use of hormones…’ The term ‘no hormones administered’ may be approved for use on the label of beef products if sufficient documentation is provided to the Agency by the producer showing no hormones have been used in raising the animals.”

Consumers should research information from reliable sources about the controversies concerning the use of hormones in beef and milk production and then decide for themselves whether they prefer hormone-free food products. These products often cost more than milk or meat obtained from hormone-treated animals because production costs are higher.

Consumers who are concerned about the possible health effects of food products from hormone-treated animals can look for foods that are certified as organic (produced without the administration of antibiotics as well as hormones). As the Academy of Nutrition and Dietetics notes, however, “all foods [produced and sold in the United States] are covered under U.S. food safety laws and regulations, regardless of production method.”

Consumer controversies over the use of exogenous hormones in beef and dairy cattle have focused on two major concerns: increased cancer risk and early puberty.

In addition, natural hormones used to treat cattle are destroyed in the human digestive tract; less than 10% of the hormones found in beef after slaughter are absorbed by the human body during digestion. Even direct injections of bovine growth hormone into humans do not affect the human body; this fact was discovered in the 1950s when some researchers used injections of bovine growth hormone in an attempt to treat children who were deficient in human growth hormone.

Health Canada has established minimum residue levels (MRLs) for the safe use of the synthetic hormones melengestrol acetate, trenbolone acetate, and zeranol in beef cattle. There are no MRLs for the natural hormones.

A series of so-called hormone scandals in Italy in the late 1970s and early 1980s led to questions about the safety of hormone-treated milk and meat and the premature onset of puberty. Doctors investigating a cluster of cases of early puberty and abnormal breast enlargement in schoolchildren in northern Italy inquired whether (illegal) growth hormone treatment cattle used to produce luncheon meat were responsible for these cases. Although it is true that the average age of children at puberty has continued to decline in the developed countries since surveys of adolescent development were first taken in the 1940s, there is no evidence that food products from hormone-treated animals are responsible for this drop in age. The factors most clearly related to the lower age of puberty in both boys and girls are improved nutrition in the West since World War II and the increase in the numbers of overweight and obese children.

There is no conclusive evidence that meat or milk produced from animals treated with exogenous hormones is less safe or less nutritious than hormone-free products. The Academy of Nutrition and Dietetics stated in 2008 that “A study of milk quality among conventional (without and with use of recombinant bovine somatotropin [rbST]) and organic varieties showed no biologically significant differences in quality, nutrients and hormones, although conventional milk had statistically lower bacterial counts.”

Research into potential links between milk from cows treated with rbST and breast cancer will continue, as it is known that breast cancer takes decades to develop and Posilac has only been used to increase milk production in the United States since 1994.

See also Cancer ; Food labeling .