Milk and health: Wading thru the hype

The Pediatric Insider

© 2014 Roy Benaroch, MD

Fiona wrote in: “I’ve seen in the news recently there’s been studies showing concern about milk consumption, especially for adults. They’re linking high milk consumption to health issues later in life. Is this true? Can you write a post on this?”

Food information, like so much else on the internet, has become one-sided and anxiety-provoking. I suppose that’s because people are more likely to click on a link like “Milk is killing you” than “Milk is a nutritious food and a reasonable part of a healthy diet, but you don’t need a ton of it, and there are plenty of other sources of calcium and protein.”

In the latest kerfuffle, we’ve got the dairy peeps versus the anti-milk crowd. On one side, people say milk and other dairy products are a good source of calcium and vitamin D and protein, all of which is essential especially for growing children and people at risk for osteoporosis; on the other side are people claiming that research shows that increased milk drinking will kill you, and doesn’t help keep bones healthy anyway. Who to believe?

Let’s back up a second. Like all mammals, our newborns thrive on a liquid diet made by our mommas called “milk.” The exact composition varies by species—for instance, goat milk has no folate, because goat babies don’t need folate—but overall it’s stuff made of water, nutritive protein, fat, carbohydrates, micronutrients, and immunologically active proteins and cells. In other words, it’s food. It’s really good for newborns and little baby mammals who cannot eat solid food yet. In nature, the amount of time newborn mammals stay on mother’s milk pretty much correlates with how much time they need to grow to the point they can eat the food their mommas eat. Then they wean, and consume bamboo, penguins, green bean casseroles, or whatever else their species typically eats. After weaning, no other animal species continues to consume milk.

Humans are unique animals, because we’ve come to rely on a system of nature-taming developments called “civilization”. Farming, which dramatically increases the food availability per acre, started about 10,000 years ago; dairy milk consumption from non-human animals began maybe 5,000 years later, once goats and proto-cows and sheep were domesticated. Milk had the advantages of being cleaner and less disease-ridden than ordinary water, and also offered good, easily-digestible calories at a time when food could be scarce. Once milk-preservation methods were developed, butter and cheese and yogurt could keep fresh for a much longer time. In many cultures, dairy products became a big part of daily intake.

So, while it’s true that no other adult mammal consumes milk—which is a favorite talking point of the anti-milk crowd—no other adult mammal consumes any farmed food, or any domesticated animals, or any cooked foods, or any omelets. We are not like other animals, and our food sources are entirely unique. Yay us.

While milk and milk products are a historically reasonable thing for humans to eat, their health benefits for mammals old enough to consume ordinary food have been overblown. Yes, they’re a convenient source of calcium and protein and sometimes vitamin D (which, along with vitamin A, is added to cow’s milk—it’s not there naturally.) But these products aren’t the only source of these nutrients. Children who don’t like milk or families who don’t want to consume cow’s milk for other reasons have plenty of other, good, healthful alternatives to get these nutrients.

Recent research has raised valid questions about the wisdom of considering cow’s milk to be an essential part of the diet. A 2014 Swedish study, widely reported in the press, is touted to have shown that higher milk consumption increased overall mortality and did not improve bone health. But the study relied on self-reported food intake dairies, and the study subjects were divided into many cohorts, only some of which showed these effects. And epidemiologic studies like these are fraught with issues of potential reverse causality and uncontrolled confounders. The authors of the study itself went out of their way to list these and other limitations of their study, and explicitly warned people not to change their eating habits until their study could be replicated and better understood; nonetheless, when reported in the press, the study was characterized as having proven that milk will kill you. That’s not what the study showed—that’s what the scaremongers want you to believe.

Milk is fine as a reasonable part of a diet. It’s not essential (at least after weaning), and if you or your children don’t care for milk or would rather eat and drink other things, that’s fine. It certainly shouldn’t be a huge part of any human’s diet after weaning, any more than any other one single foodstuff should account for most of what anyone eats. Want your family to eat healthy? Do these things:

  • Eat as a family
  • Don’t eat too much.
  • Eat a variety of things.
  • Slow down and enjoy your food.
  • Cook, clean, and shop together.
  • Grow vegetables in your garden.
  • And stop reading or even clicking on internet scare sites about food!
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3 Comments on “Milk and health: Wading thru the hype”

  1. davebrown9 Says:

    Excellent post! I’m interested, from a layman’s perspective, in the fatty acid content of our modernized food supply. Mostly, I’m concerned about the effects of excessive omega-6 linoleic acid (LA) consumption.

    I recently learned that during the third trimester of pregnancy, the mother’s body extracts fatty acids from fat stores to build brain tissue. In addition, 80 percent of breast milk fatty acid content is derived from the mother’s fat stores. We see, then, that the quality of a brain post construction/development depends upon the quality of the fat stored in the mother’s body. In cases where the mother routinely eats a diet rich in LA and deficient in the omega-3s required for proper brain development, formula feeding would likely be advantageous if it contains the correct fatty acid profile. http://davidgillespie.org/margarine-makes-kids-stupid-enough-eat-margarine/

    It also came to my attention that calves do not do well when their rations are rich in LA. In the early 1970s feed researchers realized that vitamin E is needed to protect omega-6s from oxidation when soybean oil is used as a fat replacer in the skim milk rations of veal calves. Excerpt from the introduction to an article entitled “Growth, Plasma Lipids and Fatty Acid Composition of Veal Calves Fed Polyunsaturated Fats:

    The efficacy of feeding growing ruminants various fats other than milk fat of normal composition has been studied less. Adams et al. (1959a,b) in papers describing biochemical and physiological effects of rearing calves on highly unsaturated vegetable fat, observed poor gains, ill health and high mortality…All the calves in our study, whether fed milk containing high or normal amounts of polyunsaturated fatty acids, received supplemental vitamin E. The presence of this vitamin E during these early growth stages may be the explanation for the very satisfactory growth and weight gains during the milk feeding period, which contrasts with the growth deficiencies and health problems encountered by Adams et al. http://www.journalofanimalscience.org/content/37/6/1419.abstract

    Unfortunately, for a long time, baby formula was not protected with vitamin E. Excerpt from Page 18 of Health Preserver: Defining the Versatility of Vitamin E, 1977, by Wilfred Shute, MD:

    “A most unfortunate aspect of this problem is the American Heart Association’s activity in pushing the idea of restricting animal fats, along with the addition of polyunsaturates as a protection against arteriosclerosis and heart disease in children, even in the new-born…More and more pediatricians are placing babies on formulas high in polyunsaturated fats without supplementing these formulas with additional vitamin E, something which must always be done.”

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  2. FormerPhysicist Says:

    I love your stuff, I even love this article, but “grow vegetables in your garden” is simplistic and not always good advice. It can even be harmful advice. Grow vegetables in reasonably clean soil or buy good vegetables. Please do not just assume the soil near your house is clean. I had mine tested – the lead and other heavy metal levels were incompatible with safe gardening of root or leafy crops. I can grow those vegetables by building up a raised garden and trucking in clean dirt. Doable, but neither cheap nor easy.

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  3. Dr. Roy Says:

    I agree with FormerPhysicist, thanks for comment.

    Getting soil tested is also a good way to make sure you’ve got good soil parameters for your veggies — pH, mineral content, etc can all be adjusted my adding soil amendments before planting. In many places, your local public university will do the testing at low cost. Google your location + “extension service” to find out how to get your soil tested.

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