The Science on Milk is about as clear as Milk

This week I have definitely had my crazy pants on. Pretty much cemented on. No idea why. My main ravenous research focus has been milk and specifically recombinant bovine growth hormone (rBGH). And guess what? I got many of the facts wrong while not fully reading things, but hear is what I learned now that I have simmered down a bit and actually read through some things.

First, rBGH is only approved for use in the US. The European Union, Canada and other countries don't allow it. rBGH is a synthetic hormone given to cows to increase milk production. rBGH increases the cow's milk production by increasing the hormone Insulin-like Growth Factor (IGF-1). The main concern is not rBGH, because as humans we wouldn't use this hormone (we don't have the receptors), but rather the end hormone result IGF-1. IGF-1 is a hormone that helps cells grow, and in some cases helps tumor cells develop. Now here is where the science gets murky. Early studies found a link between prostate, BREAST, colorectal and other cancers, but the strong link has not been repeatable. Some studies have found the correlation to a lesser extent.

IGF-1 concentrations are higher in milk from cows treated with rBGH. IGF-1 is not destroyed by pasteurization. However all people who drank milk, treated with rBGH or not, or those who drank soy milk not cows milk also had higher circulating levels of IGF-1. So it is unclear if there is enough of a direct relationship.However, rBGH milk adds an additional 0.9% (Cancer.org) IGF-1 according to studies. 

So while the American Cancer Society doesn't take a formal position on rBGH, I am going to go with Ben and Jerry on this one. As a scientist it pains me to go with murky evidence, but as a cancer survivor I am going with no rBGH containing dairy. Potential carcinogen is good enough for elimination for me. This means I check the label to make sure it says that it is hormone free on my dairy products or pony up the big bucks and by the organic. Oh my goodness, can we talk about how delicious organic milk is? And how long it lasts. It might be in my head, and I am ok with that.

Because I really didn't want to be this guy:

Sources:
Recombinant Bovine Growth Hormone. American Cancer Society. http://www.cancer.org/cancer/cancercauses/othercarcinogens/athome/recombinant-bovine-growth-hormone. Accessed 11/12/13.
Epstien, SS. Unlabeled milk form cows treated with biosynthetic growth hormones:a case of regulatory abdication. Int J Health Serv. 1996, 26(1):173-185.