It’s September, and all across the country children and teachers are filling classrooms, playgrounds, and school cafeterias. Some are in new buildings, some old. Some have new textbooks, some old. Some are studying subjects I never heard of in elementary school, like computers, and some are studying materials pretty much like what I studied back in the ’60s and ’70s. One subject that could be changing, and in my opinion, should be changing, much more rapidly is the subject of nutrition. I say this because of my horror in seeing that one of the greatest myths ever foisted on the American public is still being disseminated in our classrooms despite mountains of scientific evidence to the contrary. This is the myth that milk builds strong bones.
I grew up with the four food groups: meat, fruits and vegetables, grains, and milk. I accepted these food groups as nearly gospel and ate accordingly. Then in the ’90s I read an article in a magazine called Science News that rocked my world. This article not only stated that milk consumption is associated with an increased risk of hip fracture in elderly people, but it showed a chart of countries all over the world, correlating milk consumption with hip fracture rates. To my amazement, without exception the countries with the highest milk consumption had the highest rates of hip fractures, and the countries with the lowest rates of milk consumption had the lowest rates of hip fractures. More recently, Amy Lanou PhD, nutritional director for the Physicians Committee for Responsible Medicine in Washington, D.C. stated, “The countries with the highest rates of osteoporosis are the ones where people drink the most milk and have the most calcium in their diets.”
Studies by scientists all over the world support these statements. The famous Harvard Nurses’ Health Study followed 77,761 women aged 34 through 59 for 12 years. This study found that the women who drank three glasses of milk daily had double the number of fractures compared to women who rarely drank milk. The authors of the study, Feskanich, Willet, Stampfer, and Colditz wrote, “These data do not support the hypothesis that higher consumption of milk or other food sources of calcium by adult women protect against hip or forearm fractures.” Back in 1994 the American Journal of Epidemiology published a report by Cumming and Klineberg containing this summation: “Consumption of dairy products, particularly at age 20 years, was associated with an increased rate of hip fracture in old age.”
While it is true that high milk consumption initially results in increased bone mineral density, that is a short-term gain offset by long-term increases in osteoporosis risk. Author Russell Eaton states, “Dairy milk does increase bone density, but this comes at a terrible price. The latest research is showing that far from protecting bones, milk actually increases the risk of osteoporosis by eroding bone-making cells.” The scientific explanation is too lengthy to go into here, but it involves acidification of the blood and the effect of excess calcium from milk on the activity of osteoblasts and osteoclasts.
Even aside from scientific evidence, simple logic speaks clearly. Is there any other animal on Earth that drinks milk after infancy? No. Yet we still tell out school children every day that unless human beings drink cow’s milk every day of their lives, their bones will fall apart. It makes me shudder with frustration.
It is clearly time to replace propaganda from the food industry with solid science in our classrooms. Our most recent food pyramid, the one saying we should all be consuming 6 to 11 servings of grain per day, as well as showing cow’s milk as a healthy part of the human diet, was based on intensive lobbying by the food industry rather than on solid science. Most of us are aware that anyone eating 11 pieces of bread a day, plus all of the other foods shown on the food pyramid, is going to be obese, but the food industry has plenty of political clout and clearly uses this influence to its advantage.
Now, before the Dairy Farmers of Washington get all upset with me, I will add one bit of good news for dairy lovers. There are studies showing that fermented milk products, such as sour cream, yogurt, and kefir, do not cause the blood acidification that is associated with the leaching of calcium from our bones. TCBY, here I come.
Nutritional science is complicated. I’m not a scientist, I’m just a health fanatic who reads a lot. But I’m hoping that many reading this will be spurred to do their own research and educate their families on the truth when it comes to dairy milk. Maybe eventually, as was the case with the lung cancer/cigarette connection, this knowledge will become main stream. Our children’s health depends on it.
Beverly Hoback lives in Arlington and teaches music, health, and science in the Lakewood School District.
Regarding your September 21 opinion letter on milk, there is more to be said. Although cow’s milk contains calcium, it is lacking in iron, magnesium, potassium, and essential fatty acids. Why then is cow’s milk good for calves? Because calves also eat grass, which is rich in these nutrients. Drinking cow’s milk uses up our caloric allotment without delivering the nutrition we need. Most vegetables are rich in calcium and other minerals.
Milk is very high in protein, and most people consume far too much protein, which acidifies the blood and weakens bones. Cow’s milk, even if it is organic, contains IGF-1, a growth hormone identical to human growth hormone. Too much growth hormone encorages growth of cancer cells.
People love the taste of milk and cheese because it contains casomorphin, an addictive analog of morphine. It is in cow’s milk and mother’s milk to induce calves and babies to crave milk.
Finally, commercial milk is a very cruel food because calves are taken from their mothers shortly after birth to spent a hundred hellish days in veal crates. In order to keep their flesh pale in color, they are denied water and hay and are fed an iron free diet of surplus milk and butter, which makes them wretchedly ill.
The science of osteoporosis and its resultant fractures has long been plagued by some vexing observations. Why, for example, are osteoporotic fractures relatively rare in Asian countries like Japan, where people live as long or longer than Americans and consume almost no calcium-rich dairy products? Why, in Western countries that consume the most dairy foods, are rates of osteoporotic fractures among the highest in the world? And why has no consistent link been found between the amount of calcium people consume and protection against osteoporosis?
An alternative theory of bone health may — or may not — explain these apparent contradictions. It is the theory of low-acid eating, a diet laden with fruits and vegetables but relatively low in acid-producing protein and moderate in cereal grains. Its proponents suggest that this menu plan could lead to stronger bones than the typical American diet rich in dairy products and animal protein, often enhanced by calcium supplements.
These dietary changes might even prevent or delay other chronic conditions that rob far too many people of a wholesome old age.
The low-acid theory was first fully promulgated in 1968 by two American doctors in the leading medical journal The Lancet and has since been the subject of much debate and confusion among bone specialists.
At the same time, researchers at the Yale School of Medicine are studying the possible bone benefits of adding protein supplements to the diets of older Americans who habitually consume low levels of protein.
Dr. Karl Insogna, a professor of internal medicine directing the study, said in an interview that the 18-month placebo-controlled study would determine whether raising protein intake to a more normal range could increase bone mineral density and help prevent osteoporosis in people over age 60.
Science of the Skeleton
Bones are not immutable. Rather, they are continually being broken down and rebuilt, and when breakdown exceeds buildup, they get progressively weaker. Vital to the solid framework of the body, bones play an equally important metabolic role hidden from casual observation.
Bones are the storage tank for calcium compounds that regulate the acid-base balance of the blood, which must be maintained within a very narrow range. When the blood becomes even slightly too acid, alkaline calcium compounds — like calcium carbonate, the acid-neutralizer in Tums — are leached from bones to reduce the acidity.
The researchers note that fruits and vegetables are predominantly metabolized to alkaline bicarbonate, whereas proteins and cereal grains are metabolized to acids. The more protein people consume beyond the body’s true needs, the more acidic their blood can become and the more alkaline compounds are needed to neutralize the acid.
In one study by Dr. Dawson-Hughes and colleagues, published in January in The Journal of Clinical Endocrinology and Metabolism, 171 healthy men and women age 50 and older were treated with either bicarbonate or no bicarbonate. Those receiving bicarbonate, in an amount equivalent to nine servings of fruits and vegetables daily, experienced much lower levels of calcium loss in the urine, as well as a loss of N-telopeptide, the biochemical marker of bone resorption.
(By contrast, Dr. Insogna said that although eating more protein raised the loss of calcium in urine, it also improved intestinal absorption of calcium and thus might not result in bone loss.)
The Dawson-Hughes team concluded that increasing the alkaline content of the diet by eating more fruits and vegetables should be studied as a safe and low-cost approach to preventing osteoporosis and improving bone health in older Americans.
The finding is consistent with current recommendations from several federal health agencies to consume nine servings daily of fruits and vegetables. That amount has been shown to lower blood pressure and has been linked to a reduced risk of developing heart disease, stroke, diabetes, some cancers and Alzheimer’s disease. Now prevention of osteoporosis might be added to the list.
As the book authors point out, “animal foods, especially cheeses and meats, don’t contain much alkaline material” and hardly enough to “neutralize all the acids they introduce into the bloodstream; the body must draw calcium compounds from bone to restore optimal blood pH,” a measure of acidity. On the other hand, the alkaline material in fruits and vegetables, which are low in protein, can buffer that acidity.
Except for hard cheeses, which are acid-producing, most dairy foods, including milk, are “metabolized to compounds that are essentially neutral,” Dr. Dawson-Hughes said.
In their exhaustive review of the scientific literature, Dr. Lanou and Mr. Castleman found that “two-thirds of clinical trials show that milk, dairy foods and calcium supplements do not prevent fractures.” They conclude that the high fracture rate in countries that consume the most milk and dairy products results from the fact that “these affluent Western countries also consume the most meat, poultry and fish.”
Lessons From Research
This does not mean that older people, many of whom chronically consume too little protein, should avoid this essential nutrient, which helps prevent frailty and the falls that result in fractures. Nor must people become vegetarians to maintain strong bones.
But it does suggest that those at the high end of protein consumption may be better off eating less protein in general and less animal protein in particular and replacing it with more fruits and vegetables. Consider adhering to the amount of protein that health experts recommend, which has a built-in safety factor of 45 percent above the minimum daily requirement and is based on ideal (not actual) body weight and age.
For an adult, that amount in grams is 0.36 multiplied by ideal body weight. Thus, a woman who should weigh 120 pounds needs only 44 grams of protein a day, the amount in 3 ounces of flounder, one piece of tofu and a cup of cooked bulgur. A 60-pound 8-year-old (the multiplier is 0.55) would need only 2 ounces of chicken and one-half cup of cottage cheese to get the recommended 32 grams of protein.