There's a lot said these days about the hormones used to treat the animals and foods that we eat from them--such as cow's milk, cheese, beef, or lamb. Concerns among the public have been circulating for some time that girls are developing earlier and experiencing puberty at a younger age due to exposure to hormones in foods. So I decided to find out the facts.
Supplementing an animal or its food with hormones
Hormones are steroids and proteins naturally produced by the body and are found in both humans and animals. When given in supplement form--to either humans or animals--they can affect the way the body reacts or grows. It was discovered in the early to mid 20th century that supplementing an animal or its food with hormones could increase their size or milk production.
An increased risk of cancer in some cases
In some circumstances, hormones can also increase the risk of cancer. For example, increased and prolonged estrogen exposure has been linked to an increased risk of breast cancer in women. Another example is the hormone DES (which was used in the 60s to stop preterm labor and was also used as a supplement in animal feed). DES was found to cause abnormalities to the reproductive tract of female fetuses and increase those women's risk of vaginal cancer.
Hormones currently allowed by the FDA
Currently, there are six hormones allowed by the FDA to be used as an animal supplement. They are only allowed for use in cattle and sheep but not in poultry or pigs. The animals produce these hormones naturally as well. So it is expected and natural to find levels of the hormones in the animals. And while treated animals may demonstrate elevated hormone levels, they are within expected levels and not considered excessive.
The worry for women
The most common concerns for women regarding hormones in food tend to be early puberty and increased breast cancer risk. Early puberty is considered prior to age 8. There are many factors that affect the age of puberty including nutrition, genetics, height, weight, and body fat. While we have seen a decline in the age of puberty in the U.S., many argue it is attributable to nutrition and lifestyle. Very limited studies have been conducted to determine the affect of hormones in the food with no definitive results. There are currently no studies in progress. The other concern is regarding breast cancer risk. This is also a relatively unstudied area that has yet to be determined. You can read more about this on The Cancer Project website.
What can you do?
As I mentioned, any animal that you eat is going to have a certain amount of hormones naturally. The FDA does assure that levels of hormones in treated animals do not exceed prescribed levels. If you do not wish to consume treated animals, look for products labeled "organic" -- these foods must not be hormone supplemented. Remember that only cattle and sheep products (milk included) are hormone treated. If you wish to avoid meat altogether, make sure that you get complete proteins from non-meat sources.
