Science of Food: Benefits of organic milk |

Science of Food: Benefits of organic milk

Lisa Julian
Science of Food
Growth hormones are given to dairy cows to increase milk production.
Getty Images / iStockphoto | iStockphoto


What: “Going Organic” with Dr. Lisa Julian. Personal Q&A with tips on recipes and where to shop

When: Saturday May 7 noon to 1 p.m.

Where: Elevated Yoga & Holistic Health, 310 E Main St., Frisco

Cost: $20

For more information or to register visit: or call (970) 401-2071

Editor’s note: This is part three of a “Why it’s worth going organic” series. Go to for parts one and two.

What does it mean to buy “certified organic”? Let me first start off by explaining the general standards set forth by the USDA that define the “certified organic” label. Organic growers, farmers and food producers are prohibited to use genetically modified organisms (GMOs), antibiotics and synthetic hormones in meat and poultry, and require 100 percent organic feed for livestock. Products sold with the USDA certified organic seal must contain at least 95 percent of such organically grown ingredients.

This means that if the farm is not organic, then dairy cows can be treated with antibiotics and growth hormones, or may be eating genetically modified food or food containing pesticides. If you consume dairy products from cows that are eating pesticides in their food, then these chemicals can be transferred to you upon consumption. “You are what you eat eats,” as author and food advocate Michael Pollan so succinctly describes. I refer you to the last two issues to learn more about why the widespread use of antibiotics and synthetic pesticides is harmful to human health. In this article of the “Going Organic” series, I will focus on the use of growth hormones in dairy products.

Growth Hormones

Growth hormones are given to dairy cows to increase milk production. Bovine growth hormone (BGH), and specifically the recombinant version (rBGH) also known as bovine somatotropin (rbST), have been used widely on dairy farms since its approval in 1993. The actual drug administered to cows is similar to the hormone they naturally produce, but it has been genetically engineered so that it can be produced in large amounts and sold for profit. It was first developed by Monsanto under the name Posilac and is one of the top-selling animal pharmaceuticals in the U.S. It works by slowing the death of mammary cells and the result is an increase in milk production.

Use of synthetic growth hormones in meat and poultry is banned in Europe, Canada and many other countries due to the potential harm they cause to both humans and cows. Major side effects in cows treated with rBGH include reproductive problems, lameness and a condition called mastitis, when the cow’s udder becomes infected and inflamed. Mastitis can also occur when a cow is over-milked, a common practice among large dairy farms, whether they are organic or not. But the cows raised on non-organic farms are often given antibiotics to treat the infection, creating a viscous cycle of pharmaceutical use in modern dairy farming.

Connecting growth hormones and cancer

Potential harm to human health comes not necessarily from the presence of residual BGH itself. The harm comes from an increase in another hormone called insulin-like growth factor, or IGF-1. As it says in its name, IGF-1 is a growth factor. It is a very important protein that signals the body to turn on cell growth. It plays a role in normal growth and development, but it can also drive cancer growth.

Scientific evidence has already linked elevated IGF-1 levels to cancer, especially cancers of the prostate, breast, testicular and colon tissues. Edward Giovannucci, associate professor at the Harvard Medical School, has been studying the link between diet, hormones and cancer for decades. He led a large human study published in 2001 correlating IGF-1 and colon cancer, following over 32,000 nurses for a six-year period of time.

“When IGF-1 is added to dishes of cells growing in the laboratory, the cells flourish like flowers blooming in spring,” Giovannucci says. IGF-1 is a key player in regulating cell growth.

Since cancer is just that, a disease of the cell with uncontrolled and rapidly proliferating cell growth as the fundamental driver, it makes clear sense that IGF-1 would influence cancer. More specifically, we know that IGF-1 works in part by inhibiting a process in the body called apoptosis. In brief, apoptosis is a mechanism in the body to eliminate cells when the body knows the cell is damaged, a so-called “cell-suicide.” It is a fundamental pathway that is required for your body to effectively kill cancer cells. Nearly 10 years ago when I was working as a research scientist at the biotech company Amgen, we (along with many other drug companies) were creating pharmaceutical drug candidates, now patented, to initiate this very mechanism of apoptosis as a treatment for cancer. If you initiate cell-suicide, then cancer cells die faster, this being the therapeutic rationale for targeting apoptosis with a pharmaceutical drug. In contrast, if you shut if off, as IGF-1 does, then the cells can grow faster or live longer.

What to buy?

The FDA does not require that milk from cows treated with BGH be labeled as such and this has been an ongoing and highly controversial political public health issue. Unless the milk is labeled organic or BGH-free, your milk may be coming from cows treated with this bioengineered growth hormone.

IGF-1 hormone is measurably raised in cows treated with rBGH and this is transferred to the milk. BGH is degraded during the pasteurization process, but IGF-1 is not and there are some studies that show elevated levels of IGF-1 in adults who consume milk from cows treated with growth hormone. These findings suggest the possibility that IGF-1 can be absorbed by the human GI tract and can enter the bloodstream, thereby raising circulating levels of IGF-1.

Look for the “certified organic” label on milk, butter, cheese, yogurt and ice cream, as this will provide some assurance of the requirements listed above. (Stay tuned for next month’s column “Why it’s Worth Buying Organic Chicken and Eggs” for a specific discussion of chicken-derived foods). Although enforcement of the strict organic regulations set forth by the USDA can be problematic it is a good place to start, especially when buying at large supermarkets. If possible seek out smaller farms in your community at local farmers markets during growing season. You may be able to find organic foods at cheaper prices (even without the actual governmental label) from these smaller farms, owned and operated by trustworthy farmers.

Considering that the use of growth hormones in dairy farming is a relatively recent practice and knowing how it reacts in the body with a potential to fuel cancer growth, I would in no way consider this safe for humans. Even the American Cancer Society agrees that “more research is needed to address these possible health concerns.” There is too much human and molecular evidence that links synthetic growth hormones to an increased risk of cancer and it is a current risk to public health to continue the use of growth hormones in our food supply.

Dr. Lisa Julian Ph.D. is the owner of Elevated Yoga & Holistic Health in Frisco and teaches Science and Nutrition at CU Denver and CMC. She can be reached at (970)401-2071 or For more information about services offered at her studio, visit

Support Local Journalism

Support Local Journalism

As a Summit Daily News reader, you make our work possible.

Now more than ever, your financial support is critical to help us keep our communities informed about the evolving coronavirus pandemic and the impact it is having on our residents and businesses. Every contribution, no matter the size, will make a difference.

Your donation will be used exclusively to support quality, local journalism.

For tax deductible donations, click here.

Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.

User Legend: iconModerator iconTrusted User