Claim:   Milk sold at Wal-Mart contains rBST, a dangerous growth hormone.

Status:   Multiple:

• Some milk vended by retailers comes from rBST-treated cows:   True.
• As of March 2008, Wal-Mart's "Great Value" milk no longer contains rBST:   True.
• Milk produced by rBST-treated cows has been proved dangerous for ordinary human consumption:   False.

Example:   [Collected via e-mail, March 2007]

Health Warning - rBST in Great Value [Walmart] Milk I just received this from my sister-in-law in Gainesville and I wanted to let you all know, especially if you have daughters or granddaughters. Please read this and pass along to as many people.... Mitzi Lyons, her husband is Kyle, live here in Gainesville, TX. Their daughter, for THREE years has incurred menstrual problems (bleeding every day) for three years and within the last year she started producing milk. They have performed every test, every surgery, put her on birth control and the last straw was fixing to be a hysterectomy in January. BUT, Mitzi's dad started research on the internet of his granddaughter's problem and found out about rBST in milk (injecting cows with hormones so they will produce more milk). Walmart Great Value milk is the kind that the Lyons family has always drunk. 3 months ago, they pulled Marissa off of Great Value Milk and she quit bleeding and lactating. Borden milk does not have rBST in it. Her doctor's in Houston are going to write a medical journal discovery on her, because FDA says that rBST is safe. Mitzi asked me to please share this with everyone I could think of to hopefully save someone the pain and suffering that Marissa has endured. Mitzi knows this was an answered prayer. I have pulled my family from Walmart Great Value Milk and bought Borden and Borden has a label on their milk that says rBST not used on their cows. Please pass this on......

Origins:   rBST, or recombinant bovine somatotropin, is an artificial growth hormone injected into dairy cows approximately every two weeks to boost milk production. It is the synthetic version of BST (bovine somatotropin), a naturally-occurring hormone in cattle. Cows treated with rBST go from producing over 70 pounds of milk per day to somewhat less than 90, a significant increase in output.

The use of rBST is controversial. On the plus side, it elevates milk production and boosts farm income. On the downside, it can increase udder infections in cows (thereby necessitating greater use of antibiotics), and some say it may increase cancer risk in milk drinkers.

The cancer claims have not been proved. Those who say there is a risk point to a connection between rBST injections and elevation of another hormone in cows, IGF-1. In humans, too much IGF-1 is linked with increased rates of colon, breast, and prostate cancer.

Use of rBST is banned in Canada, but not because of any potential ill effect it might have on humans; its use was proscribed because of its harmful effects on cows (udder irritation).

The Food and Drug Administration (FDA) says rBST is safe for consumers and that milk from rBST-treated cows is no different from milk from non-treated cows:

Before the 1993 approval of rbST, FDA determined that the recombinant, or genetically engineered form of bST is virtually identical to a cow's natural somatotropin, a hormone produced in the pituitary gland that stimulates the production of milk. During that rbST approval process, FDA concluded that there is no significant difference between milk from treated and untreated cows. For that reason, FDA also concluded it does not have the authority to require special labeling for milk and dairy products from rbST-treated cows, and that producers have no basis for claiming that milk from cows not treated with rbST is safer than milk from rbST-treated cows.

Assurances notwithstanding, recent years have seen a grassroots consumers movement away from products reliant upon antibiotics or growth hormones. Shoppers are increasingly seeking out "rBST- (or rBGH-)free" milk in lieu of the hormone-assisted sort. But it comes at a price — this type of milk is far more expensive. While a half-gallon of 2% milk (Lucerne) goes for $1.99, its non-rBST equivalent (Sunmilk) goes for $3.89, and organic 2% milk (Horizon and Stremicks Heritage) for $4.19.

We encountered this e-mail purporting to detail a teen's reaction to the rBST in the milk she drank in March 2007. While there is reason to believe the young woman depicted in the tale exists and that the description of her travails is at least somewhat accurate, that's a far cry from saying her drinking of rBST-enhanced milk caused her medical woes. There have been rumors that rBST causes premature puberty in children, but as yet there's nothing credible to hang them upon. Indeed, arguing against such an outcome is the type of hormone itself: Somatotropins (growth hormones) are not the same as gonadotropins (sexual development hormones), and they don't cross functions, especially when applied to different species.

The e-mailed alert includes an exhortation to swear off milk from Wal-Mart in favor of that from Borden. That advice is a bit simplistic, because just about any large retailer that vends milk will generally offer both rBST and non-rBST kinds for sale. Those concerned about avoiding rBST should read labels, looking for words like "organic," "hormone free," and "rBST free." (Consumers should also assume if that they don't see one of those phrases, the product they're considering buying does contain rBST.)

On 21 March 2008, Wal-Mart announced that its "Great Value" milk would no longer be sourced from rBST-enhanced cows.

Barbara "milk dud" Mikkelson

Additional information:

bST Fact Sheet   (Cornell University)

Last updated:   23 March 2008

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  Sources:

    Pollack, Andrew.   "Which Cows Do You Trust?"

    The New York Times.   7 October 2006   (p. C1).

    Raine, George.   "Got rbST in Your Milk?"

    The San Francisco Chronicle.   25 March 2007   (p. D1).

    Reuters.   "Hormone-Free Milk Sales Stir Heated Debate."

    Los Angeles Times.   19 January 2007   (p. C6).