By Melanie Haiken
Forget sticks and stones -- your morning run may be the bigger risk to bone health. Find out why young, fit women are more susceptible to injury and osteoporosis than they realize, and how you can build stronger bones now.
"In my practice, I see healthy-looking women in their 20s and 30s with brittle bones who think they're doing all the right things for their bodies," says Elizabeth Shane, MD, a professor of medicine and endocrinology and an osteoporosis researcher at Columbia University Medical Center in New York City. "They are trying so hard to keep their weight low that they're skimping on important nutrients or working out too much. It's a recipe for early bone loss." In fact, a disturbing 15 percent of college-age women have lost enough bone mass to put them at an elevated risk for osteoporosis; another 2 percent already have the disease, according to a study from the University of Arkansas at Fayetteville. Even children are suffering: Girls are 56 percent more likely to fracture an arm today than they were 30 years ago, which researchers speculate may be due in part to lower calcium intake.
Here, your plan for stronger, healthier bones.
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1. Strong Muscles, Strong Bones
Women who engage in weight-bearing activities such as jogging or stair climbing can increase their bone mass by up to 6 percent compared with those who don't, say researchers at the Washington University School of Medicine in St. Louis. "Exercises like these, in addition to strength training, force your muscles and bones to work against one another, as well as against gravity," says Connie Weaver, PhD, who chairs the department of food and nutrition at Purdue University in West Lafayette, Indiana. "Impact exercises send a signal to your bones to build new cells, called osteoblasts, which migrate to the bone's surface and make your skeleton stronger. Without that signal, the process is slowed down." Bonus: Increasing your muscle strength and balance lowers the chance of bone-breaking falls.
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But Beware of...Too Much of a Good Thing If you work out so intensely that your period stops for at least three months, you have what doctors dub athletic amenorrhea. Basically, it means your ovaries have stopped making estrogen, an important hormone for building bone mass. (Estrogen signals cells known as osteoclasts to stop breaking down bone while also signaling osteoblasts to build more.) Exercise-induced amenorrhea occurs in up to 25 percent of all athletic women, and it's one of the most common causes of brittle bones. "Anything that lowers estrogen levels -- too much exercise or too low a body weight, for example -- interferes with building bone," Dr. Shane says. Your simple fix: everything in moderation. Mix hard and easy workout days and at least one day of rest every week. Training for a race or another event? Check with your doc to make sure you aren't overdoing it.
2. Up Your Calcium and Vitamin D
Calcium, a powerhouse bone builder, is not the "I work alone" type. It does a significantly better job at protecting your skeleton when partnered with magnesium, vitamin D, and more than a dozen other nutrients. While it is possible to get all you need from food, it's pretty darn hard. "This is especially true for women, who often stop eating dairy after childhood because they mistakenly think it's fattening, despite studies showing that consuming low- or nonfat dairy may actually contribute to weight loss," Brown says. Compounding the problem: You can get only small amounts of vitamin D through foods such as fortified milk and cereal, salmon, and egg yolks. The nutrient is mainly produced from ultraviolet B radiation in sunshine. And since basking SPF-free in the sun's dangerous rays could cause more harm than good, most American women are deficient in the vitamin, Dr. Recker notes.
What to do? Start by boosting your calcium and D as much as possible directly through your diet. Research shows that women who get their calcium through food and drink have stronger bones than those whose calcium comes from supplements alone. Next, review your diet with your health practitioner and see what kind of supplements you may need. In all likelihood, she'll recommend that you take a multivitamin and, for maximum absorption, shoot for about 1,000 milligrams of calcium and 320 milligrams of magnesium between diet and supplements. Since the proper amount of vitamin D is not yet found in a multi, you'll have to pop a separate supplement that contains between 1,000 IUs and 1,700 IUs of the nutrient. Try for a total of 1,000 IUs to 2,000 IUs of vitamin D a day.
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But Beware of...Fatty Dairy and Sun Overkill Just because calcium is crucial to bone health, that doesn't mean you have the go-ahead to pig out on a pint of ice cream whenever you please; it will pack on the pounds and up your risk of heart problems. (People who consume high-fat dairy regularly have an almost 10 percent higher risk of heart failure than those who don't, according to new research in the Journal of the American Dietetic Association.)
And while the indoor-tanning industry would love you to believe that bronzing beds offer a safe way to increase your vitamin D levels, it's not true. Not all tanning beds emit D-producing UVB rays. Bottom line? It's never a good idea to tan -- indoors or out.
Feeling blue is bad for your bones. A study from the National Institute of Mental Health found that depressed women had significantly more hip and spine bone loss than their happier counterparts. It seems that depressed women may have lower levels of bone-strengthening proteins and higher levels of other proteins that cause bone loss. They also have an excess of the stress hormone cortisol, which can weaken bones. Adding to the problem: When depressed, you tend to stay inside and exercise less, putting you at risk for vitamin D deficiency and bone loss, Recker says. (At least one study has found lower levels of vitamin D in depression sufferers.)
But Beware of...Antidepressant Excess Before battling your blues with meds, know that women who take the most widely used type of antidepressants, serotonin reuptake inhibitors (SSRIs), such as Prozac and Paxil, may be at increased risk for bone loss, according to recent studies. SSRIs are believed to help alleviate depression by allowing more serotonin, a neurotransmitter that helps control mood, to circulate. In recent years, however, scientists have discovered that serotonin, as well as depression itself, inhibits bone mass formation. More research is needed to definitively connect depression and antidepressants to bone loss, but many experts recommend monitoring bone density in at-risk women (read thin, athletic) receiving SSRI treatment. If you're concerned about the effects of SSRIs on your bones, talk to your doctor about taking additional supplements and adapting your exercise routine.
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