Guest guest Posted August 7, 2003 Report Share Posted August 7, 2003 Boning Up On Calcium Are you getting enough? Too much? The solution isn't as easy as gulping milk by the gallon or popping supplements by the handful. To call calcium the most hyped mineral in history would be an understatement. There are dozens of heavily advertised supplements on the market. On grocery store shelves, everything from orange juice to bread is fortified with it. Packages of antacids, such as Tums and Rolaids, brag about their calcium content.And no one hypes the health benefits of calcium more than the dairy industry. All these products purport to help prevent osteoporosis, the deterioration of bone mass due to calcium depletion, which afflicts 10 million Americans and causes 1.5 million fractures annually. The specter of spending our senior years stooped over like a question mark, slowly, carefully and painfully crossing the street with the aid of a cane or a walker, afraid of sustaining a serious or even fatal injury from a simple fall, is frightening indeed. It would seem, therefore, that we should all eat as many calcium-rich foods as possible and take calcium supplements to guard against this debilitating condition, right? Wrong!! At least, not without knowing what we are doing. Studies have shown that those who ingest large quantities of calcium can also be among the most at risk to develop osteoporosis. The reason for this is that the amount of calcium we ingest does not necessarily translate into the amount of calcium we absorb. At least as important as the amount of calcium in our diet is the type of calcium we eat, and what we eat with it. Certain cofactors in proper proportion are absolutely necessary for the body to absorb calcium, while other substances inhibit the body's ability to do so. The amount of gastric hydrochloric acid and the acidity (pH level) of our bodies is also of fundamental importance. Even our hormonal balance plays a key role in calcium metabolism. Without taking all these factors into account, blithely loading up on calcium can actually result in a net *deficiency* of the mineral. The bones: our blood's calcium bank Bone cells are the body's savings account of calcium. When blood levels of calcium rise above normal, the excess is stored in the bones. Conversely, when calcium levels in the bloodstream dip, the body turns to its bone bank to balance the deficit. Our serum calcium level is affected by many factors, many of which are not directly related to the amount of calcium in our diets. For example, stress can reduce free calcium by disrupting hormone balance. Stress stimulates the production of the hormone cortisol, which in turn increases levels of the steroid hormone aldosterone, a key regulator of mineral balance in the body. Chronic stress can reduce blood calcium levels, requiring the body to continually make withdrawals from the bone bank. The dairy myth There is no question that we need an adequate dietary intake of calcium. But how much is adequate? What are the best sources? And what factors are necessary to absorb and utilize this calcium and to maintain proper levels of calcium in both our bones and our bloodstreams? People equate calcium with dairy, and dairy products contribute 75% of the calcium in American diets. Milk is a $19 billion industry in the United States, and the Dairy Council spends hundreds of millions of dollars in advertising and marketing every year. The Got Milk ad campaign is among the most successful in advertising history. However, scientists long have challenged the assumption that dairy consumption equals strong bones. Now, thanks to new studies, their argument is gaining momentum. It's easy to understand why the dairy industry touts milk as the perfect calcium conveyor. An eight-ounce glass packs 300 mg of calcium along with significant amounts of vitamins A and D, magnesium and phosphorus all cofactors for bone health. Cheese and yogurt are similarly endowed. But not everyone swallows the idea that a diet chock-full of dairy is the best way to bank calcium. The dairy industry's armor was badly pierced five years ago by a Harvard Nurses' Health study published in the American Journal of Public Health. Researchers examined the diets of 77,761 women during a 12-year period. What they found was that drinking milk did not protect the participants against bone breaks. In fact, those who drank the most milk (three or more glasses a day) had more fractures than those who barely touched the stuff (less than one glass per week). I'm not surprised that people who consume a lot of dairy don't necessarily have better bones, says Diane Feskanich, lead author of the study and an epidemiologist at Brigham and Women's Hospital in Boston. Feskanich is still monitoring the nurses to see how they're faring, and she hopes to publish more data sometime this year. We updated the analysis and found the same results: We don't see fewer hip fractures with higher milk consumption, she says. There is definitely a link between protein consumption and osteoporosis. What the Nurses' Health study showed is that, as a preventative strategy against osteoporosis, eating dairy products is no better than a placebo, says Neal Barnard, M.D., president of the Physicians Committee for Responsible Medicine, a nonprofit organization that promotes vegetarianism and opposes milk consumption. The dairy industry is built on convincing people that it works. A more recent strike against the dairy industry came in the form of a scientific review published last September in the American Journal of Clinical Nutrition. Researchers at the University of Alabama gathered all of the credible clinical evidence they could find on bone health and dairy-rich diets. After an exhaustive review of nearly five dozen studies, they concluded that there is no solid body of evidence to support eating dairy foods. If dairy foods are so loaded with calcium, why are they not protective of bones? One reason is dairy products' relatively high protein and salt content. The body utilizes calcium to metabolize both protein and salt. Approximately 1 mg of calcium is needed to process 1 g of protein, and Americans routinely eat 65 to 100 g or more of protein each day. The authors of the study found that some dairy foods, such as cottage and processed cheeses, are so high in protein and sodium, which also acidifies the blood, that the combination could actually negate the food's calcium benefits. That discovery doesn't surprise Loren Cordain, Ph.D., an evolutionary biologist at Colorado State University in Fort Collins. [see Cordain's story, A Diet Solution Based on Evolution, March 2002.] Cordain is one of a growing number of theorists who believe that the crux of Americans' high rate of osteoporosis is not a lack of calcium but our Western diet: heavy on acid-inducing proteins and light on alkaline-enhancing fruits and vegetables. What we're seeing is a calcium imbalance, says Cordain. It's not about how much calcium comes in, it's about how much calcium is going out. Americans have the highest rates of osteoporosis-related fractures in the world, yet we eat more dairy products than almost any other country. The data sticks out like a sore thumb. Indeed, the facts are confounding. People in North America and northern European nations consume two to three times as much calcium as their Asian counterparts, yet break two to three times as many bones. Milk advocates chalk that up to anatomical differences. Caucasians have a longer hipbone than Asians; therefore, they are more susceptible to fracture, says Connie Weaver, P.h.D., head of the Foods and Nutrition Department at Purdue University in Indiana. Cordain doesn't buy it. Take that same theory and go to Africa, where the population has longer bones than Caucasians, and it doesn't hold up, he says. They eat 500 milligrams of calcium a day, yet the fracture rate is half what it is in the West. The United States has one of the world's highest recommended daily allowances for calcium, and it keeps creeping higher. According to the National Academy of Sciences, which sets the RDA, daily calcium recommendations start at 1,300 mg for adolescents ages 9 to 18, then lower to 1,000 mg for adults ages 19 to 50, and, finally, rise again to 1,200 mg for people 51 and older. Reaching the RDA for calcium is virtually impossible unless you're eating tons of dairy products, which is precisely the point, says Cordain. Cordain likes to refer back to the diets of hunter-gatherers for dietary guidance. He points out that milk is a recent phenomena and that if what dairy advocates say is true, then everyone living before the age of milk should have had osteoporosis. We don't find that at all, he says. What we do find are robust, fracture-resistant bones. Holistic nutritionists also point out the unnatural aspect of what was touted by the dairy industry as nature's most perfect food: No other mammal drinks milk from its mother after it is weaned, and no other species drinks the milk of another species. Feskanich is also skeptical of the RDA for calcium. Upping the calcium requirements doesn't seem to be helping prevent hip fractures in America, she says. So what does all this mean to someone who wants to eat a bone-healthy diet? The science may be complicated, but the dietary advice is not. Eat plenty of fruits and vegetables If you find it hard to believe that eating green vegetables is a superior way to get adequate calcium, consider the diet of dairy cows. These animals maintain their own huge bone structures and produce calcium-rich milk from a *diet* of grass. While it's true that, cup for cup, most vegetables have less calcium than milk, the body is able to absorb more of the mineral when it comes from a veggie source, explains Barnard, because it doesn't come packaged with protein and salt. In fact, the body absorbs more calcium from kale and broccoli than from milk. A 1997 study published in the New England Journal of Medicine found that as participants upped their fruit and vegetable intake from 3.6 to 9.5 servings a day, their calcium *loss* " declined " 30%. A minimum of five servings of fruits and vegetables a day is important for bone health because it creates a more *alkaline* environment, and consequently less calcium is lost in the urine, Weaver says. Among the richest sources of plant-based calcium are dark, leafy greens, such as brussels sprouts, mustard greens, broccoli, turnip greens and kale. But be aware: Not all calcium-rich veggies translate that calcium into bone. For example, spinach and sweet potatoes are loaded with calcium but are reluctant to deposit it as they travel through the body; both are high in oxalate and phytate, two compounds that inhibit calcium absorption. (Cooking eliminates the oxalate problem.) Don't depend on fortified foods When deciding where your calcium should come from, fortified foods belong at the bottom of your list. The vitamins and minerals added to processed foods are necessarily the cheapest available, and their sources and forms are uncertain. Foods that are *artificially* pumped full of calcium shouldn't replace natural sources. There are so many beneficial factors in food that haven't even been identified; you really need to go to foods first, says dietician Lola O'Rourke, a spokesperson for the American Dietetic Association. Watch your salt A high-sodium diet " drags " calcium from bones to *aid* digestion. Every day, the typical American eats 3 to 4 g of sodium, equaling a daily calcium loss of up to 80 mg. By reducing your daily sodium intake by 1 g, you'll save 1% of your skeletal mass each year. Be sure to use natural sea salt containing at least 2% trace minerals. And do your best to avoid sinfully salty snacks, such as potato chips and microwave popcorn. Give high-sodium, processed foods, such as frozen dinners, the boot, too. Trim animal protein Eating just one meat-free meal a day can reduce your protein intake by 40 g, meaning that 40 mg of calcium will stay in your bones, where it belongs. Plant-based proteins have the added advantage of containing fiber, an adequate supply of which is essential for proper digestive functioning. Calcium is absorbed from the small intestine into the bloodstream, and the health of the small intestine directly affects the amount of calcium we absorb from our food. Don't smoke As if you needed another reason not to smoke, consider this: Smoking increases your risk of osteoporosis. In one study of smoking and bone health, researchers followed sets of identical twins in which one twin smoked and the other abstained. In the end, the smoker had a 40% higher risk of suffering an osteoporosis-related fracture. One more reason to quit: Women smokers often enter menopause up to a year and a half before nonsmokers. Early menopause means that the body can be deprived of bone-building estrogen even longer than necessary. Shun soda Last year, scientists at Harvard found that teens quaffing soft drinks were three times more likely to break a bone than those who didn't partake. The risk of injury jumped to five times more likely for girl athletes. Some researchers point to phosphoric acid as the culprit since it's thought to hamper calcium absorption. Get plenty of vitamin D Vitamin D must be present in sufficient quantity for your body to absorb calcium from the intestines into the bloodstream. Be sure to get outside and get adequate sunlight our bodies synthesize vitamin D through the action of ultraviolet radiation on sterols (fat-like substances) in the skin. You can also add vitamin D-rich organic egg yolks and fish oil to your diet. For adults, the recommended daily allowance for vitamin D is 400 to 600 IU. Many seniors, especially those who are housebound, suffer from a vitamin D deficiency. The National Osteoporosis Foundation recommends up to 800 IU per day for the elderly. Make sure you get your fill, but don't get carried away. More than 1,000 IU of vitamin D a day can actually inhibit calcium absorption. Exercise Bone density rises and falls according to the demands placed upon it, so physical activity has lifelong implications for skeletal health. Adults who were physically active during childhood have better bone density than those who were couch potatoes. A recent study by scientists at Pennsylvania State University found that exercise during the crucial bone-building years is the best predictor of a woman's adult bone health. Researchers tracked the diets and exercise habits of 81 girls from age 12 to 18. Those girls who saw the greatest bone gains as adults were those who exercised the most during their teens, not those who consumed the most calcium. So, boost your bone density by hitting the pavement or the gym. Experts agree that 30 minutes of weight-bearing exercise, such as walking or jogging, three times a week is all it takes to see results. Strength training is also an excellent way to keep bones strong. Either way, it is never too late to start. In studies that examined physical activity among the elderly, exercise reduced the risk of bone-breaking falls by 25%. Exercise gives your bones a reason to live, says Barnard. Check your stomach acidity Calcium cannot be digested without sufficient stomach acid. It is estimated that by age 50, most Americans have lost 50% of their acid-producing stomach cells to protein overload, parasites, poisonous substances in food and other factors. Under the best of circumstances, only about 30% of the calcium we ingest is absorbed; without sufficient hydrochloric acid in our stomachs, this figure can drop as low as 4%. This is also why antacids, which claim to be a calcium " source " , actually work *against* calcium " absorption " . Ironically, many people take these products because they suffer from heartburn, which they attribute to excess stomach acid. Yet, according to gastroenterologist William Stuppy, M.D., the vast majority of his mature patients suffer from too *little* stomach acid, which can produce the same " symptoms " as excess acid. Dr. Stuppy warns especially against taking acid blockers such as Pepcid AC. For patients with chronic digestive problems, stomach pH can be easily measured during routine tests. One more way to help your stomach is to chew your food well: Food that is thoroughly masticated generally requires less stomach acid to digest. JoAnn Guest mrsjo- DietaryTi- http://www.geocities.com/mrsjoguest/classic_tan.html The complete " Whole Body " Health line consists of the " AIM GARDEN TRIO " Ask About Health Professional Support Series: AIM Barleygreen " Wisdom of the Past, Food of the Future " http://www.geocities.com/mrsjoguest/AIM.html Quote Link to comment Share on other sites More sharing options...
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