Is rBGH in US Milk Linked to Cancer? An Instagram Post Fact-Checked

The claim, and the verdict

An Instagram post from @thefarmacyreal says American milk can legally contain a hormone called rBGH (also called rBST), that the European Union "effectively banned" it in 1990, that it raises IGF-1 in milk, and that Europe outlawed it over animal welfare and "lingering concerns over potential links to cancer and early puberty." It adds that the FDA allows it without mandatory labeling and that standard American dairy "remains restricted from entering European markets."

Verdict: mixed. Much of the regulatory history is real. But the post blurs the reason for the European ban, implies a cancer link that health agencies say is not established, and makes a trade claim we could not find documented.

What is real

rBGH, also known as recombinant bovine somatotropin (rBST), is a lab-made version of a cow hormone. The American Cancer Society (ACS) says some dairy farmers use it to increase milk production. FDA approved a bST product in 1993, and the ACS notes that its use is not permitted in the European Union, Canada, and some other countries.

The ACS also says milk and meat from treated cows have higher levels of IGF-1, even though growth hormone levels are not significantly higher. So that part of the post is consistent with the ACS.

The labeling point is also right. In its 1994 interim guidance, FDA wrote that it "did not have the authority in this situation to require special labeling for milk from rbST-treated cows." Companies may voluntarily say their milk comes from untreated cows, as long as the statement is truthful and not misleading.

The European timeline

The post says Europe banned rBGH in 1990. The EU put a temporary hold, called a moratorium, on BST in 1990 and made the ban permanent from January 1, 2000. In March 1999 the EU's scientific committee on animal health and welfare had recommended against BST use.

Why Europe acted

The post lists animal welfare and possible cancer links together. The published reasoning weighs heavily toward animal welfare.

A 1999 European Commission research news report (CORDIS) said that all 18 scientists on the animal health and welfare committee concluded that BST should not be used in dairy cows. It said the hormone "substantially increases foot problems, mastitis and reactions at sites" of injection. That matches the post's mention of udder infections and lameness.

The recitals of the 1999 decision itself cite only animal-health and animal-welfare reasons: the scientific committee's finding that BST increases the risk of clinical mastitis and of foot and leg disorders, can affect reproduction adversely, and can cause severe injection-site reactions, and its view that BST "is not to be used in dairy cows." The decision text does not mention IGF-1, cancer or puberty.

On human health, a separate EU committee reported in March 1999 that BST may increase IGF-1 in milk. It noted that epidemiological studies had linked IGF-1 to a higher relative risk of prostate and breast cancer, and it called for more research. It also said the amount of IGF-1 in milk from treated cows was unknown at the time. So European scientists did raise a question. They did not conclude that milk from treated cows causes cancer. We found no source for the "early puberty" concern and could not check it.

What we know about IGF-1 and cancer

IGF-1 (insulin-like growth factor 1) is a hormone the body makes naturally. Cow's milk also contains some. Here the evidence is unsettled.

The ACS says some studies found a possible link between high IGF-1 blood levels and certain cancers, but "later studies have failed to confirm these reports or have found weaker relationships." Its bottom line: "It's not clear that drinking milk or eating meat produced with rBGH increases blood IGF-1 levels into a range that might increase cancer risk." The ACS says it has no formal position on rBGH use. It supports open regulatory oversight and more independent research.

The ACS page says a 2014 US Department of Agriculture survey found that "fewer than 1 in 6 cows (15%)" were being injected with rBGH. We did not verify a more recent figure. Many dairies do not use it, so "American milk can contain it" is true in the same way that "some American milk may not."

FDA's bST page says "milk and meat from cows treated with Posilac" (the approved bST product) "is safe for humans to eat at any time after the animal is treated," and that "numerous international health and food safety organizations and many national regulatory agencies have confirmed the safety of milk and meat from bST-treated cows." FDA's 1994 guidance uses this wording: "No significant difference has been shown between milk derived from rbST-treated and non-rbST-treated cows."

Nothing here proves that rBGH milk is safe forever or that it is harmful. It means the question is open and that major cancer and food-safety bodies have not identified a demonstrated cancer risk.

The trade claim

The post says the divide means American dairy "remains restricted from entering European markets." We could not confirm this. The EU decision we read prohibits the marketing and administration of BST within the EU; it says nothing about barring imports of milk from treated cows. An Ohio State University Extension article states that EU legislation "does not allow the use of rbST within EU member countries, but it allows imports of milk and dairy products from rbST animals into the EU." It also says no country has banned imports of milk or milk products from the US on that basis. That is a university extension source and may be dated, and we did not find an EU trade regulation on this, so we treat it as a strong sign and not the final word.

What this does not mean

• It does not mean the FDA has been shown to be wrong. Its finding of no significant difference stands, and this article does not dispute it.
• It does not mean that drinking milk raises your cancer risk. For what large reviews say about dairy and cancer overall, see Does Milk or Dairy Cause Cancer?.
• It does not mean a product with a "no rBST" label is better or worse for cancer risk. Those labels reflect how the cows were managed.
• It does not settle animal-welfare questions. Those were the main reason the EU gave for its decision.

Questions about diet and cancer risk are best taken to your care team or a registered dietitian.

Sources

• https://www.instagram.com/p/DdzfKV-qh7C/
• https://www.cancer.org/cancer/risk-prevention/chemicals/recombinant-bovine-growth-hormone.html
• https://www.fda.gov/animal-veterinary/product-safety-information/bovine-somatotropin-bst
• https://www.govinfo.gov/content/pkg/FR-1994-02-10/html/94-3214.htm
• https://curia.europa.eu/en/actu/communiques/cp98/cp9842en.htm
• https://cordis.europa.eu/article/id/12459-committee-votes-for-ban-on-bst
• https://cordis.europa.eu/article/id/12533-bstusage-causes-public-health-concern
• https://dairy.osu.edu/newsletter/buckeye-dairy-news/volume-10-issue-2/rbst-safety-around-world

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

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