Hormones in milk? It's a natural fact.

A reader writes The Green Guide:

I drink organic milk at home but stop by my local coffee house for a daily latte or other coffee beverage with milk. These places usually don't carry organic milk, or if they do, it is full-fat organic milk which I don't drink. I drink organic milk mostly because I don't want those extra hormones in my body. A nurse told me that due to the high heat needed to make espresso drinks, the hormones are essentially boiled away. I find this hard to believe. Is there any truth to this statement? And, along those lines, does conventional non-fat milk have less hormones than full-fat?

Thanks so much,
Paige Eaton

The Green Guide responds:

When speaking of hormones in milk, it is important to first clarify terms. As the FDA has made abundantly clear to milk producers, there is no such thing as "hormone free" milk. All milk, regardless of fat content, contains naturally occurring hormones that cannot be processed away. Not all milk, however, comes from cows that have been treated with recombinant bovine somatotropin (rBST), also referred to as recombinant bovine growth hormone (rBGH). rBST is presumably the source of your concern.

The Monsanto Company developed this genetically modified version of the naturally occurring pituitary hormone in cows and markets it under the name Posilac. The synthetic hormone, when injected into lactating dairy cows, increases milk production, but may cause health problems for both humans and cattle. The FDA approved the commercial use of rBST in 1993, and within a few years its use had been adopted in roughly 40% of US dairy herds. In the European Union, the use of rBST remains banned.

The health risks of rBST milk surround the increased presence of insulin-like growth factor-I (IGF-I), a mediator of growth hormone action. According to a number of studies and an NIH technology assessment statement, the concentration of IGF-I is higher in milk from cows treated with rBST. The NIH states, moreover, that pasteurization has little or no effect on IGF-I. If pasteurization doesn't do the trick, there is little reason to believe that steaming—as in your espresso—will. "There is no evidence that steaming for that time will make the IGF-I inactive, that it will mitigate the problem," said Michael Hansen of the Consumer Union Policy Institute. In short, the hormones you're worried about will not be "boiled away."

More importantly, the question is whether IGF-I remains intact through human digestion and whether it is biologically active in humans. The FDA insists that any assumption that biologically-active IGF-I is absorbed into the body "is not supported by the main body of science." Reports from European scientists, however, suggest that possible hazardous effects of IGF-I are more difficult to rule out than the FDA is letting on. The wise choice—not to mention the best for cows and farmers—is to stick to organic milk.