Growth Hormones in Food – Should You Worry?

In the United States alone, red meat represents the largest percentage of meat consumed – 58%. The total average meat in-take per day, according to the National Health and Nutrition Examination Surveys (NHANES), is 128g. This is approximately more than three times the current global average.¹

If we consume red meat in these large amounts, it makes perfect sense that there should be a reasonable amount of concern about how these meats are reared and processed for consumers. A number of steroid hormone drugs for use in beef cattle and sheep were approved in the 1950s by the U.S Food and Drug Administration (FDA). These steroid hormone drugs include estrogen, progesterone, testosterone, and their synthetic alternatives.² The synthetic form of testosterone used is trenbolone acetate, and the synthetic forms of progesterone used are zeranol, 17 beta-estradiol, and melengestrol acetate (MGA). These hormones are not approved for use in poultry or pigs. The recombinant bovine growth hormone (rbGH) is used specifically to increase milk production in dairy cattle.

Why Are Growth Hormones Used in Food-Producing Animals?

If a type of animal species is being reared for mass production, the factors for success would therefore be:

1. High rate of production (speed of growth) – certain hormones speed up the growth of animals.
2. Bulkiness of meat – certain hormones make animals gain weight, sometimes speedily.
3. Increased milk production – certain hormones used in dairy cows increase the amount of milk they produce.

Should You Worry About Growth Hormones in Food?

As always, the key to healthy living is the ability to weigh the advantages and the disadvantages to your health. There is growing concern over the link between growth hormones in food and cancer proliferation. However, there is little research in literature to support this concern, due to the fact that it is very difficult to separate naturally-produced hormones from the artificial hormones once they are injected inside the food-producing animal. Also, there is little evidence to support the link between growth hormones in food and cancer proliferation.

Nevertheless, there is supporting research to show that milk produced from dairy cattle injected with the rbGH hormone contains ten times the amount of Insulin-like growth factor (IGF) than regular milk. Are high amounts of IGF harmful? There has been ample research concerning this but none of them are conclusive. A study found that high IGF-1 may contribute to the regulation of cell proliferation, differentiation, apoptosis, and neoplasia, and may also increase the risk of prostate cancer.3 Another study shows that IGF-1 promotes breast cancer growth.³

Still, more research needs to be done on the linkage between IGF-1 and breast cancer. To maintain your health, you should do everything you can to be aware of new developments in the research of growth hormones in food.

References:
1. Daniel CR, Cross AJ, Koebnick C, Sinha R. Trends in Meat Consumption in the U.S.A. Public Health Nutrition [Internet]. 2011 April; 14(4):575-583. Available from: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8225310
2. Steroid Hormone Implants Used for Growth in Food-Producing Animals [Internet]. Silver Spring (MD): U.S Food and Drug Administration; 2011 Feb 02. Available from: http://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm055436.htm
3. Davoodi H, Esmaeili S, Mortazavian AM. Effects of Milk and Milk Products Consumption on Cancer: A Review. Comprehensive Reviews in Food Science and Food Safety [Internet]. 2013 May; 12(3):249-264. Available from: http://onlinelibrary.wiley.com/doi/10.1111/1541-4337.12011/full