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Milk-consumption guidelines questioned; scientists call for more evidence

milk shelf
How much milk an individual child or adult needs will depend on the overall quality of his or her diet.

A commentary published last week in the journal JAMA Pediatrics challenges two long-held beliefs: that low-fat milk is more healthful than whole milk and that everybody should consume a minimum of three servings of milk (or its dairy equivalent) daily.

In the commentary, Dr. David Ludwig, a pediatrician at Boston Children’s Hospital, and Dr. Walter Willett, chair of the department of nutrition and epidemiology at the Harvard School of Public Health (two very well-known and respected nutrition scientists), explain why low-fat milk may actually do more harm than good when it comes to keeping our weight in check or protecting our hearts. They also point out that the three-servings-a-day recommendation, which is advocated by the U.S. Department of Agriculture, the American Academy of Pediatrics and most other medical groups, lacks scientific support.

The two doctors are not calling for either children or adults to stop drinking milk. They just think broader and more evidence-based recommendations are needed.

Here are some of their key points:

  • Low-fat milk does not help us slim down. Studies involving children, teens and adults have shown that when we substitute reduced-fat milk for whole milk, we do not lose more weight. In fact, we may actually gain weight, perhaps because low-fat products make us feel less full, thus raising the likelihood that we’ll consume more of other foods. “Suppose a child who habitually consumes a cup of whole milk and two 60-kcal cookies for a snack instead had nonfat milk,” write Ludwig and Willett. “Energy intake with that snack would not decrease if that child felt less satiated and consequently ate one more cookie.”
  • Low-fat milk does not protect our hearts. We’re also told that low-fat milk is better for us than whole milk because the saturated fat in whole milk raises low-density lipoprotein (LDL) cholesterol, considered a major risk factor for heart disease. “However,” write Ludwig and Willett, “when compared to carbohydrates, saturated fat increases cardioprotective high-density lipoprotein [HDL] cholesterol, leaving the ratio of high-density lipoprotein to total cholesterol relatively unchanged.” Also, low-fat milk may lead us (like the child in the earlier example) to consume more high-glycemic-index foods, which, the two doctors point out, may raise levels of a third blood lipid, triglycerides, to heart-unhealthy levels.
  • Current daily milk recommendations are causing children to consume added — and unhealthful — sugars. To entice their children to get enough milk, many schools (and parents) serve chocolate and other flavored sugar-sweetened milks. These drinks make low-fat milk more palatable to young people, Ludwig and Willett point out, but they also contain many extra grams of sugar, “which clearly undermines diet quality, especially in a population with excessive sugar consumption.”

No need for animal milk

Humans have no nutritional need for animal milk, say Ludwig and Willett, and many populations throughout the world do not consume any, yet are quite healthy. Indeed, dairy products are not, the doctors stress, essential for strong bones:

Adequate dietary calcium for bone health, often cited as the primary rationale for high intakes of milk, can be obtained from many other sources. Indeed, the recommended levels of calcium intake in the United States, based predominately on balance studies of 3 weeks or less, likely overestimate actual requirements and greatly exceed recommended intakes in the United Kingdom. Throughout the world, bone fracture rates tend to be lower in countries that do not consume milk compared with those that do. Moreover, milk consumption does not protect against fracture in adults, according to a recent meta-analysis.

How much milk an individual child or adult needs will depend on the overall quality of his or her diet, Ludwig and Willett point out. And nutritional guidelines, they conclude, should reflect that fact.

“Pending further randomized clinical trials and prospective observational studies,” they write, “guidelines for milk or equivalent dairy products should (1) designate a broader acceptable range of intake, such as 0 to 2 or 3 cups per day, instead of a universal minimum requirement; (2) avoid recommending reduced-fat over whole milk; and (3) focus on limiting consumption of sugar-sweetened milk.”

The commentary appeared in the July 1 issue of JAMA Pediatrics, but is, unfortunately, behind a paywall.

Comments (3)

  1. Submitted by Bruce Bruemmer on 07/09/2013 - 12:12 pm.

    The math

    “Suppose a child who habitually consumes a cup of whole milk and two 60-kcal cookies for a snack instead had nonfat milk,” write Ludwig and Willett. “Energy intake with that snack would not decrease if that child felt less satiated and consequently ate one more cookie.”

    Okay,
    1 cup whole milk=146 calories
    1 cup skim milk = 83 calories
    1 Chips Ahoy cookie= 53 calories

    A: 1 cup whole milk and 2 cookies = 252 calories
    B: 1 cup skim milk and 3 cookies = 242 calories

    Put two kids side by side and see A feels just as satiated watching B eat his extra cookie.

    I’m not sure what this is telling us to do, if anything. By extrapolation, can I ditch the ice milk for a nice pint of Ben and Jerry’s? I’m pretty sure just reading these commentaries are bad for your health because they drive me to drink, and I don’t mean milk…

  2. Submitted by David Koski on 07/10/2013 - 01:45 am.

    Does a body good . . .

    One could easily digress into the larger political manipulations of the food groups of which there are now only four (or five, if one allows fruits to be separate from vegetables!). Milk in school lunches, milk subsidies, somehow the dairy industry horned its way in to become a major necessity.

    Two things one does not hear much of, but should be part of the debate on milk and its “requirement” for a healthy diet.

    1) The calcium gained is negated by the high protein acid imbalance resulting in the body from the consumption of milk. Requiring the calcium ions to regulate the body to a proper pH, results effectively in a loss of calcium.

    2) The relationship of homogenization of milk and atherosclerosis. The mechanical, highly unnatural atomization of milk fat to evenly distribute it throughout the milk, encapsulates an enzyme (xanthine oxidase) that would never get past the digestive tract allowing it to wreck havoc on arterial linings.

    As an adult I have no need for drinking milk and enjoy a wide variety of cheeses in moderation.

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