Does Drinking Milk Actually Make Your Bones Stronger?

New York Times

12-08-2025

Q: I've always heard that you need to drink milk to keep your bones healthy. Is that true?
For generations, Americans have been told — through school nutrition programs and advertising campaigns — that milk is an essential part of a healthy diet.
Key to that narrative was that milk builds strong bones. Your bones are made of calcium, and one cup of whole milk contains about 300 milligrams of this nutrient. So drinking three cups per day, the thinking went, must make them resilient. But that message was built on short-term studies and pushed by the dairy industry, said Dr. Walter Willett, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.
With over a third of people in the United States having trouble digesting lactose, nobody needs to drink cow's milk, said Christopher Gardner, a nutrition scientist and professor of medicine at Stanford University. Getting enough calcium is still important, especially for some high-risk groups, but there may be better sources.
What does milk do to bones?
Calcium is an essential nutrient, critical for nerve, muscle and heart function, as well as bone and tooth health. However, as with most nutrients, your body needs only a certain amount. The U.S. dietary guidelines recommend that adults consume 1,000 to 1,200 milligrams of calcium per day, but this threshold is debated among experts — and other countries, like the United Kingdom, recommend only 700 milligrams.
Past clinical trials have found that when children and adults who weren't eating enough calcium increased their consumption, whether via dairy foods or supplements, their bone densities increased by up to 3 percent. But those gains were too small to meaningfully reduce fracture risk, Dr. Willett said. And other studies have found that people must consume extra calcium every day to maintain those gains, which may not be worth the investment, he added.
'The idea that we need lot of calcium is based primarily on very short-term studies looking at calcium balance over a few weeks,' Dr. Willett said. And an analysis of 79 milk papers published between 1999 and 2003 found that over a third received funding from the dairy industry.
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