In yesterday's post I heaped scorn upon Dr. Mark Hyman, a doctor whose trip into alternative medicine has taken what I consider to be deadly detours.
However, he cited Dr. Walter C. Willett as someone against the supposed beneficial uses of dairy. Dr. Willett is as mainstream as medicine gets. He's the Chair of the Department of Nutrition and Fredrick John Stare Professor of Epidemiology and Nutrition at the Harvard School of Public Health. Moreover, he's led the most important large and long-term studies of health that pretty much anyone has done anywhere.
1. the 121,700-member Nurses' Health Study, initiated by Dr. Frank Speizer at the Channing Laboratory;
2. the Health Professionals Follow-up Study, a cohort of 52,000 men; and
3. the Nurses' Health Study II, a cohort of younger women numbering 116,000
When I kept railing at the small numbers and lack of meaning of studies on lactose intolerance found in the most exhaustive possible search of specific studies on lactose intolerance, milk, and calcium by the researchers presenting at the NIH state-of-the-science conference on Lactose Intolerance, I kept hoping they would cite some studies as major as the Nurses' Health Study. They never did.
The conclusions drawn from the Nurses' Study are opposed to all the conclusions drawn by the smaller, but more specific studies, done on dairy and calcium.
I found an article based on a Los Angeles Times article that is no longer online that summarizes Willett's understanding on the subject.
When Willett and his colleagues investigated the milk-drinking habits of 72,000 women in the Nurses' Health Study, they found that milk consumption was not associated with a lower risk of hip fracture, a measure of bone strength. In fact, women who drank milk twice a day were as likely to suffer a bone break as women who drank it once a week.
Likewise, the Health Professionals Follow-Up Study failed to find a relationship between calcium intake and bone fractures in more than 43,000 men. And a 2003 Swedish study of more than 60,000 women, which was published in the journal Bone, found no association between dietary calcium intake and fracture risk.
"We do need some calcium -- it's essential -- but the question is, how much?" says Willett, author of the 2001 book "Eat, Drink, and Be Healthy." He believes the body needs 500 to 700 milligrams of calcium daily rather than the 1,000 to 1,500 milligrams a day recommended by the dietary guidelines.
Why the difference?
Most clinical trials -- studies in which one group of people increases calcium intake and another group does not -- have shown that adding calcium to the diet increases bone density. But most clinical trials last for less than three years, says Diane Feskanich, an investigator for the Nurses' Health Study. "It could be that bone density does not continue to increase in the long run -- in fact, a study that went on for three years found that after an initial increase in bone density, it did not continue to increase in the third year."
Observational studies such as the Nurses' Health Study "are usually run over many years and in this way better suited to determine the long-term effects of high calcium intakes," Feskanich says.
Because of this, Willett was a long-time critic of the government Food Pyramid, and he wasn't afraid to say why the Pyramid was so bad.
There was not much receptivity in the 1990s, when we raised these criticisms of the food guide pyramid. It was almost an accepted religious belief that fat was bad and carbohydrates were good. Then there were lots of economic interests behind the food pyramid as well. Clearly the dairy industry is extremely well represented in the food pyramid. The beef industry is there, and it's very convenient that beef is combined along with fish and poultry and nuts and legumes. So each one of those industries can say: It's healthy to have three servings a day of our product.
In fact, the Harvard School of Public Health drew up a complete alternate food pyramid to promote what they suggest should really be in a proper diet.
Here's the part that the Hymans of the world won't tell you. The Healthy Food Pyramid contains dairy. It has this to say.
Dairy (1 to 2 Servings Per Day) or Vitamin D/Calcium Supplements
Building bone and keeping it strong takes calcium, vitamin D, exercise, and a whole lot more. Dairy products have traditionally been Americans' main source of calcium and, through fortification, vitamin D. But most people need at least 1,000 IU of vitamin D per day, far more than the 100 IU supplied by a glass of fortified milk. (See the multivitamins section, below, for more information on vitamin D needs.) And there are other healthier ways to get calcium than from milk and cheese, which can contain a lot of saturated fat. Three glasses of whole milk, for example, contains as much saturated fat as 13 strips of cooked bacon. If you enjoy dairy foods, try to stick mainly with no-fat or low-fat products. If you don't like dairy products, taking a vitamin D and calcium supplement offers an easy and inexpensive way to meet your daily vitamin D and calcium needs.
That's not exactly in line with Willett's older pronouncements. The needs and the evidence has indeed changed over time.
And compare this:
Choose fat-free or low-fat milk, yogurt, and cheese. If you choose milk or yogurt that is not fat-free, or cheese that is not low-fat, the fat in the product counts as part of the discretionary calorie allowance.
If sweetened milk products are chosen (flavored milk, yogurt, drinkable yogurt, desserts), the added sugars also count as part of the discretionary calorie allowance.
For those who are lactose intolerant, lactose-free and lower-lactose products are available. These include hard cheeses and yogurt. Also, enzyme preparations can be added to milk to lower the lactose content. Calcium-fortified foods and beverages such as soy beverages or orange juice may provide calcium, but may not provide the other nutrients found in milk and milk products.
That sound awfully similar, doesn't it? Know where it comes from? From the new, revised government MyPyramid Food Pyramid.
Notice the difference between the two? The Harvard pyramid is incredibly complicated. The consuming public is not. In one of the posts on the conference I talked about the problem of comprehension a frightfully large percentage of the American population has with even the most basic food terms. The new Food Pyramid was drastically simplified because of this very problem. In fact, read how wonderfully easy-to-understand the new presentation is:
Six swaths of color sweep from the apex of MyPyramid to the base: orange for grains, green for vegetables, red for fruits, a teeny band of yellow for oils, blue for milk, and purple for meat and beans. Each stripe starts out as the same size, but they don't end that way at the base. The widths suggest how much food a person should choose from each group. A band of stairs running up the side of the Pyramid, with a little stick figure chugging up it, serves as a reminder of the importance of physical activity.
MyPyramid contains no text. According to the USDA, it was "designed to be simple," and details are at MyPyramid.gov.
That's taken directly off the Harvard Healthy Pyramid page.
I left off a few sentences, though.
Unless you've taken the time to become familiar with the Pyramid, though, you have no idea what it means. Relying on the Web site to provide key information—like what the color stripes stand for and what the best choices are in each food group—guarantees that the millions of Americans without access to a computer or the Internet will have trouble getting these essential facts.
The USDA also chose not to put recommended numbers of servings on the new Pyramid because these differ from individual to individual according to weight, gender, activity level and age. Instead, it offers personalized Pyramids at MyPyramid.gov.
That's a problem, although not a completely fair one. The government provides a wide variety of print materials, some targeted at Spanish-speaking audiences, mothers and mothers-to-be, and different ages. I'm sure America is awash in print explanations of the Pyramid.
The other legitimate objection is that MyPyramid is not accurate or give specifics. Notice that the Healthy Food Pyramid has a dozen parts.
That's the big issue. I face it every time I sit down at the keyboard and so does every other writer about health, diet, and nutrition. How much information to give? How much to simplify? What understanding can you assume your audience has? Will they get confused by too much detail or suffer if detail is slighted?
Harvard and the government came down on very different sides of this issue. I've given you both. Read them, download them, print out the posters. Decide for yourselves.