This article, entitled "Are There More Hormones in Whole Milk?," comes from Carolyn O'Neil at BestFoodFacts.org.
We have so many choices in our grocery store's dairy case - whole milk, heavy whipping cream, 2% cheese, fat-free skim yogurt. But are there more steroid hormones in the full-fat versions of dairy products? If so, are high-fat dairy products, like whole milk and whipping cream, more likely to have more steroids than those dairy products with less fat, like fat free/skim milk?
To answer this question, we reached out to Dr. Ann Macrina, a research and teaching associate and dairy expert, at Penn State.
Dr. Ann Macrina:
"In general, higher fat dairy products contain a higher concentration of steroid hormones. However, the exact distribution between the fat and non-fat fractions really depends on the particular steroid hormone. Some steroids are more lipiphilic (more likely to combine with fat) than others.
- Approximately 55% of estrone, one form of estrogen, is found in the fat fraction of milk with the remainder in the non-fat fraction.
- Estradiol, another form of estrogen, and progesterone are more lipiphilic than estrone, and a greater proportion would associate with the fat fraction of milk.
"But, keep in mind that the overall quantity of steroid hormones in dairy products, even high-fat dairy products, is much lower than the amounts produced naturally by the body.
- For example, butter is ~80% fat, and one serving contains 1.9 nanograms (billionth of a gram) of estrogen.
- One 8-oz glass of whole milk contains 2.2 nanograms of estrogen.
- One 8-oz glass of skim milk contains 0.8 nanograms.
- The human body produces 54,000 nanograms (prepubertal boy) to 630,000 nanograms (woman) of estrogen per day."
Want to know more? Check out D is for Dairy for answers to many common questions about dairy including...
- Do hormones in milk cause early puberty?
- Should lactose-intolerant people avoid dairy?
- Do dairy products cause weight gain?
- Is organic milk healthier than non-organic milk?