The sex steroids found naturally in animal products likely exceed the hormonal impacts of endocrine-disrupting chemical pollutants.
Estrogen in Meat, Dairy, and Eggs
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Recent observed feminization of aquatic animals has raised concerns about estrogenic compounds in water supplies and the potential for these chemicals to reach drinking water. While much attention has been focused on the environmental impacts of xenoestrogens, the endocrine-disrupting industrial pollutants, relatively little research has examined the ecological consequences of environmental loading of actual estrogens. This is somewhat surprising, given that the potency of some estrogens can be thousands of times more estrogenic than typical endocrine-disrupting chemicals.
Estradiol, for example, is at least 10,000 times more potent than most xenoestrogens, and dietary exposure to natural sex steroids (in meat, dairy, and eggs) is therefore highly relevant in the discussion of the impact of estrogens on human development and health. And chicken estrogen is identical to human estrogen—they’re identical molecules. So it doesn’t matter if it ends up in our drinking supply from women taking birth control pills excreting it in their urine, or cows excreting it into their milk. The source doesn’t matter; the quantity does.
And a child’s exposure to estrogens in drinking water is about 150 times lower than exposure from cow’s milk, so our day-to-day estrogen exposure levels are more likely determined by whether or not we happen to eat dairy products that day.
Human urine is often cited as the main source of natural and synthetic estrogens in the aquatic environment, but the level of estrogen even in the urine of heavy meateaters, who have significantly higher levels, pales in comparison to the estrogens excreted by the farm animals themselves. Pig, sheep, cattle, and chickens produce literally tons of estrogen every year.
Women may excrete 16 mcg every day, but farm animals may release 10 times more, or in the case of pregnant cows, thousands of times more. Animal waste may contribute an estimated 90% of total estrogens in the environment. Five gallons of runoff water contaminated with chicken manure may contain a birth control pill’s worth of estrogen.
Estrogen levels in poultry litter are so high that when farmers feed chicken manure to their animals to save on feed costs, it may trigger premature development. Poultry manure has among the highest hormone content, quadruple the total estrogens, and nine times more 17 beta-estradiol, the most potent estrogen, which can be considered a complete carcinogen, as it exerts both tumor-initiating and tumor-promoting effects.
Who cares, though? From a human health standpoint, do we really care about feminized fish, or the appearance of intersex cockroaches? The problem is that the hormones get into our food supply. Endogenous steroid hormones in foods of animal origin are unavoidable as they occur naturally in these products.
It’s not a matter of injected hormones, which are banned in places like Europe in order to protect consumers’ health. They are part of animal metabolism, and so as a matter of fact, all foodstuffs of animal origin contain steroid hormones, and the presence of hormones in food has been connected with several human health problems, which we’ll look into next.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- P Regal, A Cepeda, C Fente. Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2012;29(5):770-9.
- A Wise, K O’Brien, T Woodruff. Are oral contraceptives a significant contributor to the estrogenicity of drinking water? Environ Sci Technol. 2011 Jan 1;45(1):51-60.
- S Combalbert, G Hernandez-Raquet. Occurrence, fate, and biodegradation of estrogens in sewage and manure. Appl Microbiol Biotechnol. 2010 May;86(6):1671-92.
- G Andaluri, R P Suri, K Kumar. Occurrence of estrogen hormones in biosolids, animal manure and mushroom compost. Environ Monit Assess. 2012 Jan;184(2):1197-205.
- D J Caldwell, F Mastrocco, E Nowak, J Johnston, H Yekel, D Pfeiffer, M Hoyt, B M DuPlessie, P D Anderson. An assessment of potential exposure and risk from estrogens in drinking water. Environ Health Perspect. 2010 Mar;118(3):338-44.
- L Aksglaede, A Juul, H Leffers, N E Skakkebaek, A M Andersson. The sensitivity of the child to sex steroids: possible impact of exogenous estrogens. Hum Reprod Update. 2006 Jul-Aug;12(4):341-9.
- D J Nichols, T C Daniel, P A Moore, D R Edwards, D H Pote. Runoff of Estrogen Hormone 17B-Estradiol from Poultry Litter Applied to Pasture. Published in J. Environ. Qual. 26:1002-1006 (1997).
- I G Lange, A Daxenberger, B Schiffer, H Witters, D Ibarreta, H H D Meyer. Sex hormones originating from different livestock production systems: fate and potential disrupting activity in the environment. Analytica Chimica Acta Volume 473, Issues 1–2, 25 November 2002, Pages 27–37.
- B E Harmon, Y Morimoto, F Beckford, AA Franke, F Z Stanczyk G Maskarinec. Oestrogen levels in serum and urine of premenopausal women eating low and high amounts of meat. Public Health Nutr. 2014 Sep;17(9):2087-93.
- C McGee, C Grougham, J Roche, A Fogarty. First Report of Intersex Roach Residing in Irish Rivers Downstream of Several Wastewater Treatment Plants. Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 112B (2012).
Image thanks to staci myers via Flickr.
Recent observed feminization of aquatic animals has raised concerns about estrogenic compounds in water supplies and the potential for these chemicals to reach drinking water. While much attention has been focused on the environmental impacts of xenoestrogens, the endocrine-disrupting industrial pollutants, relatively little research has examined the ecological consequences of environmental loading of actual estrogens. This is somewhat surprising, given that the potency of some estrogens can be thousands of times more estrogenic than typical endocrine-disrupting chemicals.
Estradiol, for example, is at least 10,000 times more potent than most xenoestrogens, and dietary exposure to natural sex steroids (in meat, dairy, and eggs) is therefore highly relevant in the discussion of the impact of estrogens on human development and health. And chicken estrogen is identical to human estrogen—they’re identical molecules. So it doesn’t matter if it ends up in our drinking supply from women taking birth control pills excreting it in their urine, or cows excreting it into their milk. The source doesn’t matter; the quantity does.
And a child’s exposure to estrogens in drinking water is about 150 times lower than exposure from cow’s milk, so our day-to-day estrogen exposure levels are more likely determined by whether or not we happen to eat dairy products that day.
Human urine is often cited as the main source of natural and synthetic estrogens in the aquatic environment, but the level of estrogen even in the urine of heavy meateaters, who have significantly higher levels, pales in comparison to the estrogens excreted by the farm animals themselves. Pig, sheep, cattle, and chickens produce literally tons of estrogen every year.
Women may excrete 16 mcg every day, but farm animals may release 10 times more, or in the case of pregnant cows, thousands of times more. Animal waste may contribute an estimated 90% of total estrogens in the environment. Five gallons of runoff water contaminated with chicken manure may contain a birth control pill’s worth of estrogen.
Estrogen levels in poultry litter are so high that when farmers feed chicken manure to their animals to save on feed costs, it may trigger premature development. Poultry manure has among the highest hormone content, quadruple the total estrogens, and nine times more 17 beta-estradiol, the most potent estrogen, which can be considered a complete carcinogen, as it exerts both tumor-initiating and tumor-promoting effects.
Who cares, though? From a human health standpoint, do we really care about feminized fish, or the appearance of intersex cockroaches? The problem is that the hormones get into our food supply. Endogenous steroid hormones in foods of animal origin are unavoidable as they occur naturally in these products.
It’s not a matter of injected hormones, which are banned in places like Europe in order to protect consumers’ health. They are part of animal metabolism, and so as a matter of fact, all foodstuffs of animal origin contain steroid hormones, and the presence of hormones in food has been connected with several human health problems, which we’ll look into next.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- P Regal, A Cepeda, C Fente. Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2012;29(5):770-9.
- A Wise, K O’Brien, T Woodruff. Are oral contraceptives a significant contributor to the estrogenicity of drinking water? Environ Sci Technol. 2011 Jan 1;45(1):51-60.
- S Combalbert, G Hernandez-Raquet. Occurrence, fate, and biodegradation of estrogens in sewage and manure. Appl Microbiol Biotechnol. 2010 May;86(6):1671-92.
- G Andaluri, R P Suri, K Kumar. Occurrence of estrogen hormones in biosolids, animal manure and mushroom compost. Environ Monit Assess. 2012 Jan;184(2):1197-205.
- D J Caldwell, F Mastrocco, E Nowak, J Johnston, H Yekel, D Pfeiffer, M Hoyt, B M DuPlessie, P D Anderson. An assessment of potential exposure and risk from estrogens in drinking water. Environ Health Perspect. 2010 Mar;118(3):338-44.
- L Aksglaede, A Juul, H Leffers, N E Skakkebaek, A M Andersson. The sensitivity of the child to sex steroids: possible impact of exogenous estrogens. Hum Reprod Update. 2006 Jul-Aug;12(4):341-9.
- D J Nichols, T C Daniel, P A Moore, D R Edwards, D H Pote. Runoff of Estrogen Hormone 17B-Estradiol from Poultry Litter Applied to Pasture. Published in J. Environ. Qual. 26:1002-1006 (1997).
- I G Lange, A Daxenberger, B Schiffer, H Witters, D Ibarreta, H H D Meyer. Sex hormones originating from different livestock production systems: fate and potential disrupting activity in the environment. Analytica Chimica Acta Volume 473, Issues 1–2, 25 November 2002, Pages 27–37.
- B E Harmon, Y Morimoto, F Beckford, AA Franke, F Z Stanczyk G Maskarinec. Oestrogen levels in serum and urine of premenopausal women eating low and high amounts of meat. Public Health Nutr. 2014 Sep;17(9):2087-93.
- C McGee, C Grougham, J Roche, A Fogarty. First Report of Intersex Roach Residing in Irish Rivers Downstream of Several Wastewater Treatment Plants. Biology and Environment: Proceedings of the Royal Irish Academy, Vol. 112B (2012).
Image thanks to staci myers via Flickr.
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Estrogen in Meat, Dairy, and Eggs
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
What kind of human health effects? Check out the sequel, my next video: Why Do Vegan Women Have 5x Fewer Twins?
What effects might these female hormones have on men? See Dairy Estrogen and Male Fertility.
The implications of this relatively new practice of milking cows even when they’re pregnant is further explored in:
- National Dairy Council on Acne and Milk
- The Acne-Promoting Effects of Milk
- Saving Lives By Treating Acne With Diet
More on xenoestrogens in:
- Male Fertility and Diet
- Alkylphenol Endocrine Disruptors and Allergies
- Dietary Sources of Alkylphenol Endocrine Disruptors
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