Posted tagged ‘dairy’

Milk and health: Wading thru the hype

December 29, 2014

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!

Got (raw) milk?

February 20, 2009

Jill said, “My pediatrician recently had a bit of a fit when she learned we were feeding our 4 year old raw unpasteurized milk. I don’t understand why this is such a big deal. Can you explain? We get our milk from my father in law who raises cattle so this is the only milk my four year old has ever drank.”

I had a hard time with this question—most of the information I could find was either from very pro-raw milk advocacy groups, or from rather bland statements from health authorities urging people to “just say no” to unpasteurized milk. I’d like to say I’ve found some good science and statistics comparing the risk of straight-from-the-farm, unpasteurized milk to commercial milk. But I haven’t.

Pasteurization itself is a fabulous way to disinfect natural foods like milk and juice. It usually involves heating milk to 165 degrees for 15 minutes (there are other protocols), which dramatically reduces the bacterial content of the milk. And there are some nasty bacteria that can thrive in milk, including forms of tuberculosis, listeria (a potential cause of miscarriages), and diarrhea-causing campylobacter, to name a few. Pasteurization reduces, but does not eliminate, the risk of infection from consuming milk. The terms “unpasteurized” and “raw” milk are pretty much used interchangeably.

I did find this statistic: between 2002 and 2007, the Centers for Disease Control tracked 1007 illnesses traced to raw milk or cheese, including two deaths. During that same time period, there was an outbreak of listeria from pasteurized milk in Massachusetts that killed three men and probably led to at least one miscarriage.

The FDA recommends avoiding unpasteurized milk, and several states have banned its sale. Some states allow it if an unappetizing gray color additive is added (it can still be used safely to feed animals.)

It’s important that farms that collect milk for consumption without pasteurization practice very clean, hygienic farming. Unfortunately, I doubt most large commercial farms do this; they probably rely on the pasteurization to “make up” for their crowded, factory-like conditions.

If families are going to consume raw milk, I would certainly recommend that they investigate the farm thoroughly, and stick with a small local source. Good hygiene is essential at every step. The milk has a short shelf-life, even when refrigerated. People with immune-compromising conditions, the elderly, pregnant women, and babies would all be at special risk for more severe infections, and should stay away from unpasteurized products.

Outgrowing milk allergy

October 19, 2008

Kelly posted: “My daughter just turned one year old and has started the switch from breastmilk to cow’s milk. She has broken out in a rash each of the three times she has had cow’s milk, so we are switching back to breastmilk temporarily. If she does turn out to have a milk allergy, what’s the likelihood that she will grow out of it? And, does the milk allergy extend to milk-based products like cheese, yogurt and cottage cheese?”

True milk allergy (sometimes called “milk protein allergy” or “IgE mediated allergy” or “type 1 hypersensitivity”) causes either hives, wheezing, severe vomiting, or a drop in blood pressure that can cause unconsciousness. Of these reactions, hives are by far the most common and the most benign. The rash is raised pink blobs, occurring anywhere on the body. For some reason, they sometimes seem to prefer the armpits or just around the belly button. Hives itch, and each individual raised area resolves on its own within twelve hours. More hives can follow, but no single spot stays in the exact same place for very long.

Children who have hives triggered by milk will usually outgrow their allergy. It may take a few years, but by kindergarten age over 90% of these children will be able to tolerate milk. (more…)

Goodbye, whole milk

July 7, 2008

A new policy statement from the American Academy of Pediatrics, published in July 2008, calls for almost all children to consume low-fat rather than whole milk to reduce their long-term risk of cardiovascular disease.

Reduced-fat milk is preferred for all children starting at age 2. For babies younger than this, starting at age 1 year reduced-fat milk should be used if there are any risk factors: obesity or risk for obesity, or a strong family history of heart disease or increased cholesterol. Since just about every child growing up in the developed world is at risk for obesity, the guideline seems to apply to just about everyone.

The guideline doesn’t distinguish between low fat (2%), skim (0%), or other varieties of reduced-fat milk. I have been advocating skim milk for all children starting at age 2, and will now also suggest low fat (2%) milk starting at age 1 for all babies. The only exception would be in children who are truly underweight, who could benefit from the extra calories of whole milk.

The policy statement also covers new information about screening for cardiovascular risk by measuring cholesterol in children starting at age 2 who are at risk. You’ll be hearing more about this soon as these guidelines are distributed and discussed, but you heard it here first!