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Scientists discover some surprising foods that keep bones strong and help prevent osteoporosis
It’s a well-known fact that diets rich in calcium and vitamin D can help prevent or slow the progression of the brittle bone disease osteoporosis. So any foods filled with these two nutrients are a smart move for fiftysomething eaters, particularly when you consider that 10 million people over the age of 50 already have osteoporosis of the hip. About 4 in 10 women over the age of 50, and 1 in 10 men, will break a hip, spine or wrist.
Just how much calcium and vitamin D does a fiftysomething body need? Government guidelines suggest at least 1,200 milligrams per day and 400 to 600 IUs (International Units) of vitamin D. But the truth is there are dozens of nutrients involved in bone health. So a healthy overall diet, one rich in fruits, vegetables, lean proteins and whole grains, is a good start for nabbing all the nutrients bones require. Still, you might want to add the following four key foods to the plan. Promising studies suggest they might give you that extra edge when it comes to building and maintaining bones.
(For the latest information on calcium and vitamin D in dairy foods, see “What About Milk?” at the end of this article.)
1. Grapefruit Instead of an apple a day, researchers at Texas A & M University are finding that grapefruit -- both the juice and pulp -- might be just the daily medicine needed to boost bone health. In 2006 these scientists reported that animals given a daily dose of grapefruit juice or orange juice (with the pulp left in) in the morning had stronger bones than counterparts who drank no citrus juice.
Later studies (done by the same researchers in 2008) specifically pinpointed grapefruit juice for its ability to enhance bone mineral deposits and improved bone density. They also discovered the pulp of red grapefruit had the ability to slow down the rate of bone loss and spark higher bone mineral deposition, factors that improve bone quality. Researchers suspect high antioxidant levels in grapefruit could be responsible. One precaution: grapefruit doesn’t mix well with some medications, like statins (for lowering blood cholesterol), calcium channel blockers (for heart disease/blood pressure) and antihistamines. Compounds in the fruit negatively interact with these drugs and can cause serious problems.
2. Olive Oil It's a well-established heart-healthy benefit of the Mediterranean diet. But Spanish researchers wondered if olive oil could also be one of the reasons why the incidence of osteoporosis is lower in the Mediterranean basin. They answered that question in a 2012 study of 127 middle-aged and older men (55 to 80 years old) who followed one of three diets for two years. The findings: Men eating a Mediterranean diet enriched with virgin olive oil had higher levels of circulating osteocalcin, a marker of bone health, than men in the group assigned to a nut-rich Mediterranean diet or a low-fat diet.
“The intake of olive oil has been related to the prevention of osteoporosis in experimental and in vitro models,” said the study's lead author, Dr. José Manuel Fernández-Real of Hospital Dr. Josep Trueta in Girona, Spain. "This is the first randomized study which demonstrates that olive oil preserves bone, at least as inferred by circulating bone markers, in humans.”
There's a Catch 22 with the findings: High levels of osteocalcin don’t necessarily equate to increased bone density or a lower risk of fracture. They’re simply a marker of good bone health. Bottom line: It’s a bit early to crown olive oil as a magic bone elixir, says the National Osteoporosis Foundation. Yet, its overall health benefits make olive oil “an excellent choice to add to your diet.”
3. Sardines According to the National Institutes of Health, “lack of calcium has been singled out as a major public health concern because it is critically important to bone health.” These tiny fish are often overlooked as not only being great sources of calcium, but superstars when it comes to the other bone-strengthening mineral, vitamin D.
One can (3.75 ounces) of sardines naturally provides 351 milligrams of calcium (from the small fish bones) and 178 IUs of Vitamin D -- about half the requirements -- from fish oils. Compare that to an 8-ounce cup of 1% milk, which has about the same amount of calcium (349 milligrams) but is fortified with less than half the amount of vitamin D, about 98 IUs. Of course, there are no medical studies to support sardines as a good food for bone health, just the obvious facts of their natural nutrient density. Wondering how to enjoy canned sardines? Add them to salads, casseroles, pizzas or bruschetta. Or try these healthy Eating Well recipes.
4. Walnuts and Flaxseed Oil While much is made of the omega 3 fatty acids in fish, a 2007 Nutrition Journal study finds that plant-based omega 3 fats, also known as alpha-linolenic acids, could help keep bones strong. In this study, researchers at Penn State fed high amounts of walnuts (as well as walnut granola, honey walnut butter and walnut pesto) and flax oil to a small group of overweight, mostly middle-aged adults. They reported a decrease in the rate of bone breakdown and noticed that bone formation stayed constant.
How so? The scientists measured biological markers of bone health, ones that show up in the blood when bones are being built and ones that show up in the blood when bones break down. "If less bone is being resorbed and the same amount of bone is being created, then there is a positive balance for bone health," said Dr. Rebecca Corwin, associate professor of nutrition. She and fellow researchers also point out that "recent epidemiologic data suggest that the effects of dietary fats on bone health may be particularly strong in men."
Another plus: In 2010 Penn State researchers found that a diet rich in walnuts helps lower blood pressure and stress.
(MORE: Milk Alternatives: Are They Really Better for You, or Is It Hype?)
What About Milk?
Everyone knows that dairy foods are a good source of both calcium and vitamin D. But what do you do when you’re either lactose intolerant or don’t like dairy? Do you really need milk to keep bones strong? Experts at Harvard School of Public Health offer a review on both sides of the issue and suggest that it’s easily possible to increase and maintain bone health without dairy.
Think about many Asian countries, like Japan, where people eat very few, if any, dairy foods. Yet osteoporosis is rare. Consider too that in Western countries where dairy is eaten at high levels, the number of osteoporotic fractures is one of the highest levels in the world.
On the surface these two facts appear to be major diet contradictions. But one new theory may hold an explanation: Some experts suggest that many of the protein-rich foods in Western diets produce acid, and that high levels of acidity might weaken bones. Speculation is that diets low in acid -- ones rich in fruits and vegetables and with moderate amounts of cereal grains and low-acid producing proteins -- might, on the other hand, help strengthen bones. An excellent article by New York Times health writer Jane Brody gives all the details of this low-acid diet theory.
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