Does Milk Contain Estrogen?

Hormones in milk is a topic that several readers have asked Best Food Facts about. We recently received this question from Petula. “Is there estrogen in milk?”

The answer: Yes. Milk comes from animals and it contains hormones, including estrogen.

One of our experts, Dr. Ann Macrina, explained that estrogen is a steroid hormone that is found in higher concentration in higher fat dairy products. But Dr. Macrina wants to remind you that the overall quantity of steroid hormones in dairy products such as milk, ice cream, cheese products is much lower than the total amounts that are naturally produced in the body.

“For example, butter is about 80 percent fat, and one serving contains 1.9 nanograms (billionth of a gram) of estrogen. One 8-ounce glass of whole milk contains 2.2 nanograms of estrogen. One 8-ounce glass of skim milk contains 0.8 nanograms. The human body produces from 54,000 nanograms to 630,000 nanograms of estrogen per day,” she said.

Check out this infographic that breaks down hormone levels in foods compared to pregnant women, adult women, adult men, and pre-pubescent children for better understanding of the numbers.

What about hormones and early puberty? Again, Dr. Macrina says that all living things, including cows, produce hormones and growth hormones naturally. Does this mean that growth hormones in milk are causing early puberty in girls? Dr. Macrina doesn’t believe so:

“The age at which puberty begins in girls has been decreasing since the mid-1800s. It is odd to blame it on dairy products since dairy consumption has actually decreased during the same timeframe.”

She goes on to explain that one reason girls are maturing more quickly because of access to better nutrition.

Another expert, Dr. Terry Etherton, says:

“There are zillions of protein hormones in both plant and animal foods. They are digested in the stomach, which kills their ability to have any biological activity. There is just no way to come to a science-based conclusion that hormones in food or dairy products cause early puberty.”

Another question we have received is if there are health benefits to drinking organic milk. Not according to Dr. Wondwossen Gebreyes. Organic milk is not healthier, nor does it prevent you from ingesting growth hormones. Dr. Gebreyes states that there is no nutritional difference between organic and conventional milk and that all milk is tested before reaching the market based on strict FDA regulations. Whether drinking organic or non-organic work, Dr. Gebreyes encourages everyone to eat a balanced diet.

This is one of the many questions surrounding milk today. Is plant-based milk better? Are there hormones in milk? Are there growth hormones in milk? Do those hormones cause early puberty? Is organic milk better? Last year we wrote about the “myths” of dairy, concerning lactose intolerant, weight gain, hormones and organic milk. These questions are good to ask and we’ll continue to bring you science-based answers.

Yes, there is estrogen in milk and it is safe to drink because milk still contains 16 of your essential nutrients.