How can my diet help me stave off osteoporosis?
The foods you eat can work to keep your bones strong as you age, and some can even help you replace lost bone mass. If you're a woman, you're at particularly high risk for osteoporosis, the brittle-bones disease. After menopause, declining estrogen stores cause women to start losing bone at a rate of about 3 percent a year.
Eighty percent of those suffering from osteoporosis are women, and many more women over the age of 50 have some degree of serious bone loss, which contributes to about 2 million fractures annually.
Of course, it's important for men to realize that they can have osteoporosis, too. Because the disease is much more common in women, men sometimes fail to realize they are at risk even if they begin showing symptoms.
Get plenty of calcium
Your body uses this mineral to build bone, and the typical American woman gets less than two-thirds the daily amount of calcium she needs. All adults under 50 should be getting 1,000 milligrams a day; after 50, that amount goes up to 1,200 -1,300 mg.
The easiest way to add more calcium to your diet is to eat more green, leafy vegetables and dairy products. Eight ounces of milk, 1.5 ounces of cheddar cheese, 2 cups of cottage cheese, or 1 cup of yogurt provides about 300 mg of calcium, or nearly one-third of the daily requirement. Fortified orange juice and cereal are also good sources. If you aren't able to get enough calcium from your diet, consider taking a calcium supplement that has 300 mg per tablet.
Calcium supplements have recently been linked with a small absolute risk of heart attack, which has prompted some experts to call for people to get most calcium from their diets rather than supplements. If you are unable to meet the requirements and you must take a supplement, experts say it's best not to take calcium pills of more than 500 mg per tablet in one dose. By breaking up the supplements over the course of a day, calcium levels in the blood don't increase beyond normal.
Get your vitamin D
Your body needs it to shepherd calcium to your bones. Ten to 15 minutes of early morning sunshine three times a week (when you're not using sunscreen) may enable your body to make all the vitamin D it needs, unless you live in an area that is not sun-soaked or doesn't get enough sun in the winter. Just in case, the dietary allowance for vitamin D is that all adults under age 50 get 200 IU a day (those over 50 need 10-15 mcg or 400 to 600 IU).
Even this may not be enough, according to some experts. The National Osteoporosis Foundation recommends that adults under age 50 get 400 to 800 IU a day and those age 50 and older get 800 to 1,000 IU per day. To make this easy for you, the government requires that milk be fortified with the nutrient. Many cereals also contain some vitamin D. If you suspect that you're not getting enough vitamin D from these sources, or if you're over 65, consider taking a multivitamin that contains it.
Don't overdo it on the meat
Too much animal protein can interfere with the way your body absorbs calcium. When federal researchers set the daily requirement for this mineral, they assumed that you'd be eating the recommended two servings of animal protein (6 ounces total, or two pieces about the size of a deck of cards) each day. For every additional serving you eat, it's a good idea to drink an extra glass of milk in order to make sure you're still getting enough calcium.
Cut back on booze
Drinking more than two alcoholic beverages per day can harm bone cells and disrupt their absorption of calcium and vitamin D.
Eat more soy
Foods rich in soy protein may help prevent bone loss and even aid you in building bone after menopause. Although some tofu provides calcium, researchers think that it may be the phytoestrogens, particularly one called genistein, that really protect your bones. These chemicals appear to work somewhat like estrogen, functioning as a sort of natural hormone-replacement therapy.
In one study, postmenopausal women who ate 40 grams of soy protein every day for six months increased bone mass in their spines by 2 percent, while those who didn't eat any continued to lose bone. However, study results are mixed. A recent 2-year study of the effects of soy protein on bone mineral density in postmenopausal women found no benefit to preventing bone loss.
One note of caution -- some studies suggest that genistein may stimulate the growth of estrogen-sensitive breast cancers and might interfere with the cancer-fighting drug tamoxifen. So if you have had estrogen-sensitive tumors, it would be wise to limit soy unless your doctor instructs you otherwise. You can get more soy into your diet by snacking on roasted soy nuts, tossing some tofu into a vegetable stir-fry, and using soy milk on your cereal or in smoothies.
National Institute of Arthritis and Musculoskeletal and Skin Diseases, Consensus Statement on Optimal Calcium Intake Published in JAMA.
Duffy c, Cyr M. Phytoestrogens: potential benefits and implications for breast cancer survivors. J Womens Health (Larchmt). 2003 Sep;12(7):617-31.
Mayo Clinic. Osteoporosis. Updated June 2009. http://www.mayoclinic.com/health/osteoporosis/
National Osteoporosis Foundation. Fast Facts. http://www.nof.org/osteoporosis/diseasefacts.htm
March of Dimes. Calcium. http://www.marchofdimes.com/pnhec/159_9472.asp
Office of Dietary Supplements. Fact Sheet: VitaminD. http://ods.od.nih.gov/factsheets/vitamind.asp
Osteoporosis Foundation. Clinician's Guide to Prevention and Treatment of Osteoporosis. http://www.nof.org/professionals/Clinicians_Guide.htm
National Osteoporosis Foundation. Prevention: Vitamin D and Bone Health.
Vupadhyayula, PM. Effects of soy protein isolate on bone mineral density and physical performance indices in postmenopausal women: A 2-year randomized, double-blind, placebo-controlled trial. Menopause. 2009 January 21.