You’ve probably seen the ‘Got Milk’ ads before, the ones with celebrities sporting a milk mustache with a list of the nutrients found in milk.
As kids we were told to “drink your milk” for its calcium content because “calcium is good for your bones”. Virtually all governmental food guidelines include milk and dairy foods in their recommendations for this reason but also because milk and dairy foods are high in protein, phosphorus, potassium, with a smattering of B vitamins. Fluid milk is fortified with vitamin D to prevent rickets in children – a successful public health policy; certainly easier for parents than trying to get their children to take cod liver oil like they did in the past. Fair enough.
However, another idea that persists is that drinking milk or eating milk products causes osteoporosis but does it really?
The idea that dairy is unfit for human consumption comes for the so-called ‘alternative’ health camp with arguments such as ‘humans are the only species that drink the milk of another species’, a curious notion. Somehow it’s OK for humans to eat the eggs of another species because, I guess, we can find examples in the animal world where that occurs – snakes, raccoons, possum, chimps etc.
Sure, whatever.
Or fear mongering about milk being loaded with antibiotics and growth hormones, it is not. There’s no shortage of evidence to the contrary – with a little effort and homework, this is easily verifiable. Sorry, I’m not going to the work for those who won’t.
Let me be clear up front. I could not care less if someone includes milk or dairy foods as part of their diet. It doesn’t matter to me. It’s a personal choice and don’t look for subtext in this post that I am ‘pushing big dairy’. We need nutrients and we get nutrients from food; there’s lots of ways to get calcium and the other nutrients without consuming dairy foods AND if your blood levels of vitamin D are adequate, you won’t need to consume lots of calcium anyway. You don’t need milk or dairy to have a healthy diet but milk and dairy can be part of a healthy diet. I don’t go out of my way to include it but at the same time don’t go out of my way to avoid it.
Dairy Consumption And Bone Health
The bulk of the arguments center around an unsubstantiated diet theory called the ‘acid-base’ diet, also called the ‘acid-alkaline’ or ‘acid-ash’ diet or their dietary principles which claims certain foods acidify the body. I wrote about it here before [note it was at a symposium sponsored by the Dairy Farmers of Canada but the research is available for anyone to read, the facts remain].
The idea is that certain foods, once digested, lower the pH of the blood [more acidic] thereby requiring this acid to be neutralized. The body supposedly compensates by pulling calcium from the bones to neutralize the acidic blood. The rub is that the body’s acidity/alkalinity, a.k.a. pH is tightly controlled by the kidneys [which produce bicarbonate], the lungs [blowing off CO2] and within each cell [suffice it so say it happens; it gets tricky when we start talking about how hydrogen ions are shuffled around].
If your blood pH ever moved from its tightly controlled range – you’d be in the hospital fighting for your life. News flash, the pH of urine does not reflect the pH of blood so using urine pH sticks is useless. The idea that milk and dairy changes the pH of blood is simply not supported by evidence, see study.
Milk And Dairy Does Improve Calcium Status
People often argue that dairy is a poor choice for calcium because the calcium in it isn’t absorbed as well as it is from other foods. True enough if you’re just looking at the % of calcium absorbed. Case in point: 1/2 cup of broccoli has 38 mg of calcium and 52.6% of it is absorbed but only provides 20 mg. Compare that to poor milk with only 32% of i’s calcium being absorbed; but wait, 32% of 300 mg per 8 oz serving = 100 mg. You get the point.
Clinical studies have shown that consuming milk does lead to more calcium being absorbed and retained by the body. Several other studies have shown that milk and dairy food consumption is associated with lower rates of osteoporosis in post-menopausal women and milk and dairy consumption is a predictor of osteoporosis risk and better bone health as adults.
Bottom Line
Healthy bones need more than calcium. Simply drinking milk is not enough so I don’t want anyone thinking it is but milk and dairy foods can be part of a healthy strategy towards hanging onto to the bone that you have. Milk and dairy foods have never been shown to increase body acidity, nor leach calcium from bones so relax and enjoy your favourite glass of milk or kefir, yogurt, whey protein powder or cheese if you in fact include dairy in your diet – it will not cause osteoporosis. Note, after you’ve had 2 servings of dairy, more will not offer more benefits.
