Is Milk Bad for Your Bones?
There's a rumor going around that dairy products contribute to osteroporosis by acidifying the body. Nutrition Diva gets to the bottom of the controversy.
Nutrition Diva listener Rona writes:
"My health coach says that I should avoid milk because it is acidic and, contrary to common belief, will actually deplete the calcium in my bones. I have always believed that milk was a good source of calcium. In fact, I insist that my children have at least 2 servings of milk a day! Does milk really deplete calcium from bones? Should I stop giving it to my kids?"
The idea that milk and dairy products weaken bones has been steadily gaining traction in alternative health communities. Of course, this runs contrary to the conventional wisdom that dairy products help build strong bones by providing calcium. Is the conventional wisdom wrong? Let's take a closer look at the evidence..
Do Dairy Products Cause Osteoporosis?
People who are suspicious of milk's role in bone health like to point out that the countries with the highest consumption of dairy products also have the highest incidence of osteoporosis. Is this convincing proof that dairy products cause osteoporosis? Not even remotely.
There are many things that affect bone health, including genetics, physical activity, body weight, smoking or exposure to second hand smoke, alcohol use, hormone levels, and medications. Ifany of those risk factors are more common in countries that have higher dairy consumption, then the link between dairy and osteoporosis may be nothing more than a coincidence.
See also; How the Media Sensationalizes Science
If we're going to take this hypothesis -- that dairy products cause osteoporosis -- seriously, we need more than just a correlation. We need a plausible mechanism -- an explanation for how dairy products might weaken your bones.
Is Your Diet Too Acidic?
Like Rona's health coach, some people have argued that milk weakens your bones because it is an "acid-forming" food. The idea is that milk leaves an acidic residue in your body after digestion. This supposedly causes your body to pull calcium from the bones to keep your body from becoming too acidic.