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Health
No Milk? What About My Child's Bones?
by Linda Folden Palmer, DC
The most common question a vegan will hear once someone learns they don't feed their children milk: What about their bones? Yes, our mothers and grandmothers have been well taught all their lives by the dairy industry that animal milk consumption is required for humans to "build strong bones." Yet, each successive generation, consuming more and more dairy, demonstrates weaker and weaker bones. Something doesn't gel here.
Before Westernization hit various populations of Asia and Africa, many of their calcium consumption rates were quite low. The amount of "weak bones," or osteoporosis was quite low as well, translating to very few bone fractures. As each Asian and African population takes on more-Western diets, their bone fracture rates climb. In contrast, medieval as well as modern Northern European populations display the decreased bone density signs of osteoporosis, though it's worse today than historically.
Archeological studies of bone densities in early populations around the world typically report a reduction in bone strength with the transition from hunter-gatherer to agricultural livelihoods. Some blame the difference on levels of exercise. Exercise is a portion of the picture but exercise analyses do no correlate consistently with osteoporosis findings.
What's the real difference? Milk. Northern Europeans have been consuming dairy for thousands of years. Most African and Asian populations have not, until very recently.
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Calcium and Bones: The Big Dairy Fallacy
While the National Osteoporosis Foundation tells us we need more calcium to build stronger bones, especially from cow's milk, the scientific evidence simply does not support this.
The Chinese University of Hong Kong performed successive studies in the 1990s analyzing milk and calcium intake as they relate to the growth of children. This was an ideal place and time for such an investigation, because cow's milk was just making its way into popular use in that country, and the traditional diet was not high in calcium.
The first study looked at children from birth to five years of age. With 90 percent of the study children drinking milk, their average calcium intake was 550 mg. At age five, the current level of calcium intake for each child did not correlate with their bone mineral levels.1
In the second study, seven-year-old children were given calcium supplements to bring their daily calcium intakes up to 800 mg. Over 18 months no increases were seen in height or arm or leg bone density beyond those not supplemented, although some improvement in spinal bone density was seen.2 At ages 12 to 13, calcium intake did not correlate to bone mineral content, except that the girls who consumed the higher levels of calcium had lower bone density in their arms.3
In both of these studies, higher weight and greater physical activity were strongly associated with higher bone mineral content. By adolescence, neither calcium intake nor physical activity had any more influence on bone mineral improvement.4 A 14-year British study found that in young adults, their early teenage body weight and physical activity levels determined their bone mineral densities, with a slight effect from calcium intake.5
In a widely quoted study by a British hospital, researchers provided an extra glass of cow's milk to adolescent girls' diets, comparing their growth to those who drank an average of just over one half cup per day. Total daily calcium intake at the beginning of the study was 750 mg, and the extra milk group increased to 1,100 mg. The researchers reported about 10 percent greater bone growth rate for those with the extra milk.6 These children also gained a little more weight, but not height. The reported extra bone density could not be validated by any changes in the blood enzyme markers that typically reflect bone growth and bone re-absorption. Insulin-like growth factor was also found to be higher in the extra milk group.
Several experts wrote replies to this study, which had been paid for by the U.K. dairy industry. One expert, doing his own math from the study, found the milk group to have a slightly lower average total bone mineral content at the end of the study.7
A U.S. study on child twins found some increases in bone density in the arms and spine with calcium supplements (not milk).8 Once puberty began, however, calcium provided no benefits.
While dairy promotions include praise for the protein of milk as well, this protein may be more of a problem in osteoporosis than calcium could be a solution. The animal proteins of meat and dairy products cause calcium loss,9,10 unless you read the studies supported by the dairy industry.11 The level of calcium needed in the diet depends greatly on the amount of animal protein intake.12 For many of the high animal protein diets of Americans, it may not be possible to consume enough calcium in the diet to compensate for the amount lost to these high-acid proteins.13 For this reason, Americans have among the highest osteoporosis rates in the world, while their dairy intake is also among the highest. Doubled animal protein causes 50 percent more calcium loss. Yet, when a high protein intake is soy-based, a positive calcium balance can be maintained with only 450 mg of calcium per day.14
In 1986 a Harvard researcher produced a graph that demonstrated a nearly direct relationship between calcium intake and hip fractures—the more calcium, the more fractures.15,16
A 1987 study of 106 adult women suggested that calcium intakes between 500 and 1,400 mg per day led to no differences in bone mineral densities.17
A larger Italian study found that in women who consumed between 440 and 1,025 mg of calcium per day, a slightly increased number of hip fractures occurred with higher milk intakes.1819
A study of 78,000 nurses found that women who drank more than one glass of milk per day had a 45-percent greater chance of hip fractures compared to those who drank far less.19 Those who took in the same amount of calcium from nondairy sources saw no such increase, nor a decrease in fractures. Since many studies are performed on women only—they do suffer more osteoporosis—Harvard researchers decided to look at men. They found that those who drank three or more glasses of milk per day, compared to one or less per week, had very slightly fewer hip fractures, but these were balanced by slightly more arm fractures.20 The highest calcium intakes from food and supplements together produced an increase in fractures overall.
Even post-menopausal women are not found to benefit from high amounts of dairy or calcium. A 2003 follow up of the nurses study found that of 72,337 postmenopausal women, there was no reduced fracture risk between those consuming above 1,200 mg of calcium and those with less than 600 mg.21 High milk consumption was also not associated with a lowered risk of fractures. Adequate vitamin D levels were found to be important.
Race Against Milk
There is a discrepancy in the U.S. between Caucasian and other residents in terms of bone fragility. Those of African or Asian descent very commonly lose lactase enzyme (for digesting the baby milk sugar, lactose) in later childhood whereas Northern Europeans have developed a lactase enzyme persistence over hundreds of generations of survival on animal milks. Many of Asian and African descent are thus intolerant of milk and try to avoid much consumption of at least liquid milk. This likely accounts for their lower fracture rates when compared to whites; higher than historical native rates but lower than modern Caucasian rates. Media releases often portray Asian-Americans as having lower bone density due to lower milk consumption but their fracture rates, the only measure that matters, are lower as well.
The rate of hip fractures in the U.S. for people of many races and ethnic origins is exactly inverse to their rates of lactose intolerance. In other words, those who are likely avoiding milk as adults have the fewest fractures. Non-Hispanic white women have 139 fractures per 100,000 people; Mexican-Americans have 67 per 100,000; and African-Americans average 55 per 100,000.22
The indigenous peoples of South Africa have not traditionally been dairy consumers. Their consumption is still very low, although infant formula is making great inroads. Those of osteoporosis age today however would not have been raised on formula. Typically, these South Africans consume only 200 mg of calcium per day, but their rate of fractures is extremely low—fewer than seven per 100,000 people per year.23 Compare this to their dairy-exposed American counterparts. The milk-drinking (and higher calcium intake) populations around the world are the ones who have osteoporosis as a major problem.24 Again, these rates are increasing in typically low fracture areas around the world as these regions adopt Western practices.
In Japan, as in many other non-Caucasian populations, dairy intake has traditionally been minimal and calcium intakes have been low—and hip fracture rates are low, but have been growing recently,25 as is the portion of adults who were raised on dairy. While industrialization also brings reduced physical exercise, there is a much more consistent common denominator seen in the timing and geographic regions of these bone problems—cow's milk. While we feel our nutrition is superior today over centuries past, archeological research has shown that Caucasian post-menopausal bone loss in the 18th and 19th centuries was less than that seen today.26 Clearly, high calcium intake, and certainly high dairy intake, are not the prevention for osteoporosis.
Bone density is an easy indicator to measure and compare but it does not actually tell the whole story. The entire concern with osteoporosis is bone fractures. Bone density does not always correlate to bone fracture occurrences, especially when comparing different kinds of diets. Diets high in fluoride, for instance, will create bones that appear quite dense on X-ray but that are brittle and break easily. Studies on standard vegan diets reveal lower bone densities for vegans overall, along with a calcium intake about half the average omnivore intake, but they do not find an increase in bone fractures.27 That's the whole answer in a nutshell.
Milky Messages
Why the conflicts between the bulk of research findings and the recommendations of the National Osteoporosis Foundation (NOF)? The bulk of their funding comes from dairy industries. Other funding comes from small and large private donations, with some from the federal government.28 Another big supporter of the NOF is Bozell Worldwide, the marketing firm that created the huge milk mustache campaign for the dairy industry. Only two percent of the NOF's funding has gone to osteoporosis research.
Good, Bad, and Curious Solutions
Other common foods that are excellent sources of calcium, listed in order of highest amount per calorie, are: molasses; dark salad greens; cabbage; broccoli; green beans; cucumber; peas; soybeans; squash; most other types of beans (including cocoa); kiwi; real maple syrup; brown sugar; and tomatoes. In addition to this list is of course human milk. Calcium may also be added to corn tortillas and some orange juice, apple juice, and rice and soy milks. When these foods are the major source of calcium, and meat intake is not high, USRDA levels may be in excess of needs.
The World Health Organization suggests that 400 to 500 mg of calcium per day is appropriate for adults. In sharp contrast, the United States RDA for calcium was recently raised from 800 mg to now 1,000 to 1,300 mg daily for adults, depending upon age and maternal status. Ours is the highest recommendation in the world. Beyond these, the U.S. National Institutes of Health (NIH) has incrementally raised its recommendations to as high as 1,500 mg for those pregnant or nursing.
"The preferred source of calcium is through calcium-rich foods, such as dairy products," asserted the consensus statement of the NIH's Development Conference on Optimal Calcium Intake.29 It reinforced vitamin D intake too, which is added to milk, and naturally derived from sun exposure or eating fish. It does not, however, mention any of the other nutritional factors that are just as important for bone development—those that are inadequate in milk. At the same time, the report makes taking calcium supplements sound very complicated. Boron, copper, magnesium, manganese, zinc, vitamin C, vitamin K, and proper fluoride levels are just as important as calcium for optimal bone growth. None of these are high in cow's milk, so none of these are advertised as important for bones.
Phosphorous is important for bone development as well, but cow's milk has too much of this, causing decreased calcium availability. This is apparently why phosphorous is not mentioned, either. Nor does NIH mention that reduced animal protein consumption would help calcium levels. (Remember that the beef industry is the other end of the dairy industry.) Deep in the text they mention some other foods naturally high in calcium, but only in reference to vegans. This list is rather inaccurate and exclusive, sounding quite distasteful (cups of collard greens and sardine bones). They also emphasize that a little pain and gas should not prevent the lactose intolerant from having at least two servings of milk per day.
As more problems become apparent with milk, and people buy less, greater measures are taken to encourage milk-drinking. The motto for the government's Healthy People 2000 initiative was, "at least three cups of milk every day" for "every body." The NIH, whose initial intentions are often better than its final reported conclusions, funded half of the huge 1997 study that showed that nurses have more fractures when consuming more milk. To date, however, it has not changed its recommendations about milk consumption.
Masking Milk Meanings
All the while, the American Dietetic Association, with grants from the dairy industry, continues to publish reports such as "Many Asian-American elderly consume an inadequate amount of dietary calcium."30 Their conclusions are based on milk consumption, not bone fracture rates. It's obvious what their recommended solution was.
A 2001 dairy commercial shows young men playing basketball outside (i.e., exercising and soaking up vitamin D), which are two great ways to build stronger bones. A milk carton stands alongside urging them to go inside, sit down, and have some milk for their bones. TV ads are no longer allowed to directly say that drinking milk will strengthen your bones so they make every effort to intonate it, relying upon their past reputation. We've seen milk mustaches on various healthy looking celebrities and "Got Milk?" ads where someone is frantically at a loss after consuming a big piece of cake. A new ad shows a growing pregnant lady eating cheese every day, and then a smiling baby. Unfortunately, 30 to 50% of babies suffer painful colic and GER reacting to cow's milk proteins from the diets of their breastfeeding mothers or in their infant formulas.
Dutch dairy researchers have come up with a new milk product designed to be better for bone health. They increased the calcium content and lowered the protein, phosphorus, and fat content—in other words, they lowered the dairy content. Not surprisingly, elderly people taking this new low-milk calcium supplement lost less calcium each day than those drinking normal milk.31
Deflating Dairy
The norms promoted as desirable for childhood growth rates and puberty are based on a comparison of those who consume bovine growth hormones (natural in all milk, and often additionally supplemented), early and regularly, to those who are raised on natural foods. While the same height is achieved in the end, with obesity more common on the side of dairy consumers,32 those with the so-called superior nutrition experience a traumatic increase in cancer, heart disease, diabetes, and many other diseases.
The highly promoted idea that milk builds "strong bones" refers to the prevention of osteoporosis—this is the reason for strengthening bones. Decades of effort to demonstrate that high calcium diets chiefly derived from dairy products build strong bones have failed to prove any such correlation. In fact, the opposite seems to be true.33 It appears that moderate calcium intake before puberty, and especially in young childhood, may have some slight positive effect on bones, but a milk diet is not the answer. A balanced intake of all the bone minerals, along with adequate vitamin A, C, D, and K, is what is truly needed. A balanced intake of minerals cannot occur when the diet emphasizes dairy. Dairy's high calcium content causes relative deficiencies in magnesium and other bone-building minerals, and its high phosphorus and animal protein reduces calcium availability. Eating more protein doesn't make your muscles stronger, physical activity does—the same is true for bones—the body efficiently uses what is available to build strong bones when it senses the need. Human milk and vegetable sources are superior to dairy for calcium and other nutrients in many ways. There are fewer nutritional or other health advantages to giving cow's milk to children than is generally believed, while there are certainly many risks.
If you pay attention to health research announcements in the news, you will notice that almost every day another finding is made about whole grains; soy; a serving of vegetables; two fruits per day; cashews; legumes; fish; or some other food—other than milk, that is—and their connection to a reduced risk of heart disease, breast cancer, stroke, diabetes, or other diseases. This is because cow's milk and its derivatives today make up one third of the adult diet and half to two-thirds of caloric intake in children, thus replacing so much other important, nutritious food needed in the diet. This leads to insufficient intake of some important vitamins, several minerals, and healthy fiber and vegetable oils. Cancer-preventing antioxidants in foods are missing in the milk diet. While one form of anti-oxidant vitamin A is added to milk (but not all dairy products), and likely counteracted by the pesticide and drug residues, the full complement of vitamin A and associated enzymes found in vegetables and other foods are required for cancer prevention. Many more kinds of antioxidants are found in vegetables, legumes, fruits, and grains.
 So, how much calcium does a vegan need? The 2006 report that reviewed multiple studies on vegans and could find no increase in bone fractures indicated that vegans in the studies were averaging around 600 mg per day; half the RDA. The soy study mentioned above found positive calcium balances with a daily 450 mg. These findings do not mean that lower levels are not adequate. A study on pregnant women found benefits to fetal bone density development from maternal calcium supplementation only when mothers' calcium levels were below 600 mg (above 600mg they did not need any more calcium). 34 This sounds like a good suggested lower level for pregnant women who are not consuming dairy.
At the same time that diabetes and cancer concerns, along with animal compassion and other concerns, may limit the amount of dairy that should be consumed, it also appears that bone protection is no reason to promote dairy consumption. In the absence of dairy consumption, RDA levels for calcium are needlessly high.
Linda Folden Palmer, DC, author of Baby Matters, What Your Doctor May Not Tell You About Caring for Your Baby, is a widely recognized writer, educator, and consultant in infant and child nutrition, lactation, and infant health and bonding.
References
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