What do hormones in food do to you?

December 19, 2025 •

5 min read

According to scientific literature, all living organisms, including plants and animals, naturally produce hormones to regulate their life cycles. The question of what do hormones in food do to you has led to public debate regarding the health impacts of both natural and added hormones in our food supply.

Quick Summary

Hormones in food, both natural and synthetic, raise health concerns like endocrine disruption, potential cancer risk, and early puberty. Scientific perspectives vary, stressing informed choices regarding dietary hormones and endocrine-disrupting chemicals.

Key Points

All food contains hormones: No food is completely 'hormone-free,' as all plants and animals naturally produce their own hormones.
Added vs. natural hormones: Synthetic hormones can be added to beef cattle in some countries, but poultry and pigs are not permitted to receive them. Organic meat prohibits added hormones.
Protein vs. steroid hormones: Protein hormones, like rBST in milk, are typically broken down and rendered inactive by human digestion, unlike steroid hormones which are fat-soluble.
Endocrine disruption risk: Some dietary hormones and environmental chemicals (EDCs) can mimic or interfere with the body's endocrine system, potentially impacting reproductive and overall health.
Cancer link is debated: While some studies suggest a link between high consumption of hormone-treated products or IGF-1 and certain cancers, regulatory bodies and others argue the evidence is inconclusive and the risk is minimal.
Early puberty concerns: Research has explored a potential link between dietary hormones and early puberty, though factors like obesity are also significant contributors and no definitive link is proven.
Organic options reduce added hormones and EDCs: Choosing organic products can reduce exposure to synthetic growth hormones in meat and some EDCs from pesticides and feed additives.
Phytoestrogens are much weaker: Plant-based estrogens (like those in soy) are significantly less potent than human estrogens and are often digested differently, making their impact distinct.

Understanding Hormones in Food

To understand what hormones in food do to you, it is crucial to differentiate between the various types and their origins. Hormones are chemical signaling molecules that play vital roles in the growth, development, and reproduction of all organisms. The hormones we consume come from three main sources: naturally occurring animal hormones, synthetic hormones added for production purposes, and plant-based compounds with hormonal activity called phytoestrogens.

Naturally Occurring Animal Hormones

All meat, poultry, and dairy products inherently contain natural hormones because they are derived from living animals.

Estrogens and Progesterone: These sex hormones are present in animal products like milk and beef. Levels are generally higher in pregnant cows and in full-fat dairy products, as steroid hormones are fat-soluble.
Insulin-Like Growth Factor-1 (IGF-1): A naturally occurring polypeptide, IGF-1 is involved in growth and cell proliferation. Some studies have linked high levels of IGF-1 to increased risks for certain cancers, though this is debated.

Synthetic and Added Hormones

In some agricultural systems, synthetic hormones are used to enhance growth and production. In the US, synthetic sex hormones (like estradiol and testosterone) can be used to promote growth in beef cattle, while recombinant bovine somatotropin (rBST or rBGH) was previously used to boost milk production in dairy cows. The European Union, however, banned the use of growth hormones in meat production in 1989.

Phytoestrogens and Other Compounds

Some plant-based foods contain phytoestrogens, compounds that can mimic the effects of estrogen in the body.

Soy Products: Soybeans and soy products like tofu and soymilk are well-known sources of isoflavones, a type of phytoestrogen.
Other Plant Sources: Phytoestrogens are also found in nuts, seeds, and cereal grains.
Other EDCs: Beyond hormones, the food supply can be exposed to other endocrine-disrupting chemicals (EDCs) from pesticides and food packaging plastics, such as BPA and phthalates.

The Scientific Debate and Potential Health Effects

The impact of dietary hormones and EDCs on human health is a complex and often contentious topic, with differing views among scientific and regulatory bodies.

Endocrine Disruption and Hormonal Imbalances

Some research suggests that synthetic hormones and other EDCs can disrupt the body's sensitive endocrine system. This disruption can interfere with the synthesis, secretion, transport, and action of the body's natural hormones, leading to potential hormonal imbalances.

Potential Cancer Risks

Epidemiological studies have explored links between the consumption of hormone-treated products and certain cancers. The EU's ban on some growth hormones was influenced by evidence suggesting carcinogenicity for certain substances. However, other studies show conflicting results or inconclusive evidence. High levels of naturally occurring IGF-1 in some animal products have also been flagged as a potential concern due to its link with cell proliferation.

Reproductive and Developmental Concerns

There are concerns that exposure to dietary hormones, particularly during sensitive developmental stages like childhood and prenatal development, could have lasting effects.

Early Puberty: Some studies have investigated a potential link between consumption of hormone-treated foods and early onset of puberty, though the evidence is not definitive and many factors contribute to this trend, including obesity.
Reproductive System Effects: Exogenous estrogens can interfere with the hypothalamic-pituitary-gonadal axis, potentially affecting reproductive development and function.

The FDA and Safe Consumption Levels

The U.S. Food and Drug Administration (FDA) has consistently stated that minute levels of added hormones in approved beef products and milk are safe for human consumption. The FDA argues that protein hormones like rBST are broken down during digestion, rendering them biologically inactive. Additionally, they point out that the amount of estrogen in hormone-treated beef is minuscule compared to both a human's daily production and the amount found naturally in other foods like soy.

Conventional vs. Organic Food and Hormones


Feature	Conventional Food Production	Organic Food Production
Use of Synthetic Hormones (for animals)	Yes, specifically allowed in US beef cattle production for growth promotion (e.g., estradiol, testosterone). Use in poultry and pigs is prohibited.	Prohibited. Animals are raised without any added synthetic hormones.
Use of Synthetic Hormones (for dairy cows)	Recombinant bovine growth hormone (rBST) has been used to increase milk production in the past, though its use is declining due to consumer preference.	Prohibited. Animals are not given synthetic growth hormones like rBST.
Inherent Hormones	Contains naturally occurring hormones from the animal, similar to organic products, though levels can vary depending on feeding practices.	Also contains naturally occurring hormones from the animal, as they are a natural part of any animal's biology.
Endocrine-Disrupting Chemicals (EDCs)	Potential exposure from pesticides, herbicides, and other chemicals used in conventional farming.	Reduced exposure to EDCs from pesticides and herbicides, as synthetic versions are prohibited.

Making Informed Food Choices

For consumers concerned about hormones and EDCs in their food, several practical steps can be taken:

Choose organic for animal products. Opting for certified organic meat and dairy ensures that no synthetic growth hormones were added to the animal.
Consider product labeling. Look for labels like "No added hormones" on beef, but remember this is not legally required for poultry or pork as it's already prohibited. Milk labels stating "rBST-free" are common.
Eat a balanced diet. Focusing on a variety of whole foods, fruits, vegetables, and lean proteins can help mitigate the potential impact of any single food source and support overall endocrine health.
Wash produce thoroughly. To minimize exposure to pesticide residues that can act as EDCs, wash all fruits and vegetables carefully.
Be mindful of food packaging. Reduce the use of plastic containers, especially when heating food, as EDCs like BPA and phthalates can leach into food.
Stay informed. Consult reputable sources like the National Institute of Environmental Health Sciences (NIEHS) and the FDA for the latest research and information on EDCs and food safety.

Conclusion: Navigating the Complexities of Dietary Hormones

There is no such thing as a truly "hormone-free" food, as all living organisms naturally produce them. The debate around hormones in food is complex, involving both naturally occurring compounds like IGF-1 and phytoestrogens, as well as synthetic hormones and other EDCs. While regulatory agencies like the FDA in the US maintain that levels in conventional products are safe for consumption, especially since protein hormones are digested, some studies continue to raise concerns about potential health effects related to endocrine disruption, cancer risk, and developmental impacts, particularly with high intake of certain products and exposure to other environmental EDCs. Ultimately, informed consumer decisions, such as choosing organic options or focusing on a balanced diet rich in whole foods, can help address these concerns while supporting overall health and well-being. For further information on the role of nutrition and hormones, see the detailed review in Nutrients.

Sources

News-Medical.net: Sex Hormones in Meat and Dairy Products - News-Medical.net
National Institute of Environmental Health Sciences (NIEHS): Endocrine Disruptors
Iowa Farm Bureau: Are there hormones in meat and milk? What every parent should know
European Commission: Hormones in meat - European Commission's Food Safety
You and Your Hormones: Hormones and eating
ResearchGate: Naturally occurring hormones in foods and potential health effects
MDPI: Additives in Processed Foods as a Potential Source of Endocrine-Disrupting Chemicals (EDCs) and Their Health Hazards
Mayo Clinic: Organic foods: Are they safer? More nutritious?
Ann-Marie Shepherd: How Organic Food Supports Hormonal Health and Fertility

Frequently Asked Questions

Scientific debate exists on this topic. While some concerns have been raised, especially regarding children's intake of certain products, there is no definitive proof that hormones in meat and milk directly cause early puberty. Factors like obesity also contribute significantly to the trend.

The amount of estrogen consumed from dairy products is extremely small compared to the amount a human body naturally produces. While some dairy products, especially full-fat varieties from pregnant cows, have higher levels of natural estrogen, consumption does not significantly impact human estrogen levels.

Soy contains phytoestrogens, plant-based compounds that can weakly mimic estrogen. However, moderate consumption is generally considered safe and some studies suggest protective health benefits. The estrogenic effect is much weaker than endogenous human estrogen.

The link between hormones in food and cancer is a debated topic with mixed evidence. Some studies suggest potential links between high intake of certain animal products and hormone-related cancers, while many regulatory bodies, including the FDA, state that the levels are too low to pose a significant risk.

No food is truly hormone-free, as all plants and animals produce hormones naturally. However, certified organic animal products are produced without the addition of any synthetic growth hormones or antibiotics.

EDCs are chemicals from sources like pesticides and food packaging that can interfere with hormonal functions. They are different from naturally occurring or added hormones but can still disrupt the body's endocrine system.

Cooking can denature some protein-based hormones, but steroid hormones, which are fat-soluble, are more heat-stable. However, even if not fully destroyed, many hormones from animals are not biologically active in humans after ingestion.

Organic milk comes from cows that were not given the synthetic growth hormone rBST, while conventional milk might be. However, many conventional dairy producers have also stopped using rBST due to consumer demand. All milk contains natural hormones regardless of production method.

IGF-1 is a naturally occurring hormone. While high levels are linked to certain cancer risks, the amount absorbed from milk is not typically enough to cause concern for healthy adults. Neonates, however, may absorb more, which is beneficial for growth.