Dietetic Intern Rachel is back this morning to share a little nutrition research about milk and growth hormones. Whether you guzzle whole milk or hemp milk, I hope this will provide a little depth into the dairy industry.
Milk. You’re either a fan, somewhere in between loving and hating it, or you can’t tolerate it at all. For me, I’m a fan. When I hear milk I not only think of the many benefits that it reaps but it reminds me of my childhood. Growing up I was the little girl running around outside barefoot, playing in the straw bales, helping in the garden, riding shotgun in a tractor and waking up to the sound of cows mooing off in the distance….you know the typical things kids experience when growing up. HA! As you might have gathered, I grew up on a dairy farm. My appreciation for the hard work that goes into production of the nourishing food we consume, specifically a glass of cold milk, blossomed as the little girl with long, blonde pigtails ran around outside waving at her dad working hard out on the farm.
Even though I wasn’t aware at the time, my childhood would be considered unique. I would come to realize that my childhood instilled in me an appreciation for the countless hours worked and strategies farmers use to produce the wonderful food that we consume day in and day out.
So back to milk. I use it to make overnight oats, to top off my coffee, or with a snack after a hard workout. Obviously growing up on a dairy farm, I grew up drinking cow’s milk and still drink it to this day for a couple of reasons:
- To support all the hard-working dairy farmers out there
- To reap its benefits. Milk is a great source of protein, calcium, vitamin D and various other nutrients our bodies will benefit from.
More and more I have come to notice that people are choosing to not drink cow’s milk for a variety of reasons. Why people choose to switch from cow’s milk to plant based milk I’ve noticed falls on a spectrum. Maybe they’re lactose intolerant, maybe they prefer the flavor better, maybe because it’s the hot new thing to drink, and maybe it’s because of the growth hormones in milk? Wait, what? Growth hormones in milk? Yes, I must admit that even as a child growing up on a dairy farm, I knew very little about this topic. Could this be true? Is it something to be worried about? This topic recently came up in conversation with someone and it intrigued me. To get a grasp on these lingering questions and thoughts, I did what any curious soon to be Registered Dietitian would do and went to the literature and my favorite farmer (aka Dad) in hopes of some concrete answers.
The consumption of milk dates back to as far as 4,000 B.C. and would continue to evolve to a time when it was discovered that cows injected with growth hormones, specifically bovine somatrophin (bST) would cause an increase in milk production. bST is a protein hormone produced by the pituitary gland of cows that naturally increases milk production but is also necessary for growth, development, and overall health maintenance. Injection of this hormone was just another strategy along with proper hydration and nutritious feedings to increase a cow’s milk production. In the 1980’s, recombinant DNA processes would make it feasible to produce large amounts of bST. This artificial growth hormone would become known as recombinant bovine somatrophin or rBST. The FDA would approve the synthetic hormone in 1993 after extensive review of the safety of the product and its impact on consumers. Even with the approval of the FDA fears of the synthetic hormone would surface.
The concern was that cows injected with rBST had elevated levels of insulin-like growth factor (IGF-1), but it was found that cows injected did not have a higher level of IGF-1 than those cows that did not receive the synthetic hormone. There is a lot of concern around IGF-1 but it is actually found naturally in humans. Studies have shown that cows treated with rBST have resulted in a slight increase in IGF-1 in humans. Even so the FDA determined this not an issue of human food safety concern once it was determined this level was less than the natural occurring IGF-1 observed in the milk of lactating mothers. Elevated levels of IGF-1 have been associated with some cancers in humans, but follow-up studies have either been weak or inconsistent with results found in earlier studies.
As I was looking through the research, it appears that the rBST hormone itself has been well researched and reviewed by the NIH (National Institute of Health), the joint World Health Organization/Food and Agriculture Organization Committee (WHO/FAO), the American Medical Association (AMA) and the Academy of Nutrition and Dietetics (AND). What would benefit from more research is a look at IGF-1 and the inconclusive results of studies previously done.
The cool thing about this topic is that the majority of farmers have gotten away from using rBST because it is expensive and not needed. As of 2007, 85% of dairy operations were not using rBST. Farmers opt for other strategies such as nutritious diets, proper hydration and comfortable living conditions for cows to improve the quality and production of milk. Milk corporations have listened to the fears of the consumers and have labeled whether or not their milk products are rBST-free. There should be no concerns over rBST if you are choosing to consume a milk that is labeled free of artificial hormones. All Grade A milk which makes up approximately 95% of our milk supply is required by law to be tested for antibiotic or animal drug residues before it is processed. Any milk found positive for these things is rejected for human consumption. As you can see there are many precautions taken to keep the safety of the consumer in mind.
What I want you to take away from this is that dairy products are just fine in moderation. Yes, IGF-1 and its impact on humans still needs to be studied more, but the amounts that we consume have not been found to be concerning. Dairy products are a wonderful source of nutrients as are many other plant-based products. Whether you choose to consume cow’s milk or not, is ultimately up to you. Personally, I am still going to enjoy my glass of cold milk while thanking my local farmer for all the hard work they do ?