When I got my diagnosis of osteoporosis, you could've knocked me over with a feather -- scary, because according to my ob-gyn, my brittle bones were four times more likely to fracture in a fall.
As a healthy, 41-year-old mother of two young children, I thought I was years, even decades, away from the chronic condition I associate with grandmas. I ate reasonably well, exercised regularly, and kept up with the kids. However, I had had about nine years' worth of shots of the contraceptive Depo-Provera, not knowing at the time that it could harm my bones.
You, too, may think that your youth makes you invulnerable. Read on to learn how to protect yourself.
Bone is constantly broken down and rebuilt in a process regulated by estrogen: Bone-eating cells (osteoclasts) gnaw at existing bone, leaving holes that bone-forming cells (osteoblasts) fill in, using body stores of calcium. If the destroyers outpace the builders, the skeleton weakens.
Unfortunately, no symptoms occur to alert a woman of her increasing vulnerability to a fracture. It's a silent, gradual process of epidemic proportions: Almost 8 million women ages 50 and older have osteoporosis (estrogen, the bone-protecting hormone, naturally nosedives following menopause), and 10.5 million cases are predicted by 2020.
"That number includes women who are in their 30s today," says Felicia Cosman, MD, clinical director of the National Osteoporosis Foundation. Bone loss starts well before menopause, she says.
A recent study of 164 women ages 18 to 30 revealed that 2 percent of these young adults actually had osteoporosis, and another 18 percent had osteopenia -- bones with abnormally low density that are not yet porous (hence the term "osteoporosis"). "These are the years when women should have the strongest bones because they're still building bone mass, which peaks around age 30," says the study's author, dietitian Lori Turner, PhD, associate professor of health science at the University of Arkansas College of Education and Health Professions.
Major risk factors include family history and being female, Caucasian, Asian, and slender. There's no changing your genetics, sex, or race, and no one suggests you gain weight to save your bones (obesity leads to other serious health risks), but a lot can be done to build as much bone as possible throughout your 20s -- and to hang onto what you have later in life.
Daily decisions about eating, exercise, and contraceptives may help determine whether your bones stay strong or start to thin prematurely.
Calcium is vital for maintaining bone during the 30s and beyond. To make sure you get enough calcium every day (at least 1,000 milligrams), follow this guideline, says Dr. Cosman: Hit the target of at least three servings daily by including a calcium-rich food at breakfast, lunch, and dinner, or as a snack.
Where to find calcium: To achieve this, drink skim milk or consume low-fat dairy products. Other good natural sources are almonds, canned salmon with bones, and legumes. (Calcium-rich broccoli and leafy greens such as kale and collard greens also pack your daily dose of vitamin K, another nutrient that plays a key role in calcium regulation and bone formation.)
You can also get the mineral from fortified foods like orange juice, cereal, and soy products. Check food labels to see if you're getting roughly 300mg of calcium at each meal. If you fall short, ask your doctor to recommend a supplement, like calcium chews or an antacid.
Calcium and pregnancy: It's critical for pregnant women to have the recommended daily amount of calcium because the fetus takes its mom's store to feed its forming bones. In a new study, bone scans done on teen mothers revealed that one-third had either osteoporosis or osteopenia, and those with brittle bones had taken in too little calcium while pregnant. Teens with the highest calcium intake had the healthiest bones. Although most skeleton strengthening occurs during the teens, the process continues for another decade, and 20-something moms-to-be who skimp on calcium may also be more vulnerable to bone loss, says lead study author Kimberly O'Brien, PhD, associate professor of nutrition at the Johns Hopkins Bloomberg School of Public Health, in Baltimore.
Breastfeeding also temporarily lowers bone density as your baby literally sucks the calcium out of you -- but your bones will survive unscathed so long as you make sure you take in 300 to 500mg more than the general recommendation for the nutrient daily, says Kathy Diemer, MD, clinical director of the Bone Health Program at Washington University School of Medicine, in St. Louis.
Vitamin D is just as important as calcium because it helps usher the mineral into bones, which is why many calcium-rich products are fortified with D. Few foods naturally contain much of the vitamin, but the body makes its own when sunlight touches the skin.
Here's the rub: Sunscreen blocks the production of D. To prevent skin damage, O'Brien suggests a compromise. Apply sunscreen after you get 5 or 10 minutes of exposure to the sun. When sunshine is scarce, get D from your diet or a supplement.
"Taking a calcium supplement isn't enough to save your bones, which are living tissues and require nutritional balance from whole foods and lean meats," says nutritional epidemiologist Katherine Tucker, PhD, of the Friedman School of Nutrition Science and Policy at Tufts University, in Boston. Whole, unprocessed foods include fresh fruits and vegetables and whole (not enriched or bleached) grains.
New research suggests that protein, once believed to leach calcium from the skeleton, actually enhances absorption. Good protein sources include:
And kick the colas: Tucker looked at the bone densities of 1,600 women ages 40 and older. Those who downed more than one 12-ounce cola daily -- either with caffeine or without, regular or diet -- had hip bone scores 2 to 5 percent lower than those who drank less than one cola a week. "Colas contain phosphoric acid, which may prevent calcium absorption," says Tucker. Non-colas like orange and lemon-lime soda don't contain it.
Weight-bearing exercise such as running, jumping rope, and strength training builds bone. Studies show that simply jumping straight up in the air -- feet together, 50 times -- three times a week, increases bone mass. But don't expect low-impact or everyday activities, like swimming, housework, and easy walking, to do the trick, says Kara Witzke, PhD, associate professor of exercise science at Norfolk State University, in Virginia. You need to regularly overload the bones with bouncy movement or use weights over 5 pounds.
Tip for busy new moms: "Walk with your baby in a front- or backpack." Take this advice seriously. Utah State University researchers found that women with two or more kids had stronger bones than moms of one. The extra weight from carrying postpregnancy pounds or toting around kids might put a beneficial stress on bones, says study researcher Heidi Wengreen, PhD. (Plus pregnancy also causes an estrogen increase, which aids bones, says Dr. Cosman.)
Depo-Provera isn't safe for bones. This contraceptive seems new-mom-friendly because it's safe for breastfeeding, but the progesterone-only formula suppresses ovulation. When ovulation halts, so does production of estrogen. (Birth control pills containing estrogen may be more bone-friendly, according to some researchers.)
In one study, Depo-Provera users lost hip bone at the rate of 1.2 percent a year, compared with just 0.05 percent for nonusers. Fortunately, studies suggest that the losses may be recouped once the shots stop. "The safest birth control choice is ultimately the one that best helps a woman avoid pregnancy while also considering potential side effects," says Dr. Cosman.
The steps to reverse osteopenia or even full-blown osteoporosis typically are the same as those for prevention. Change your diet and exercise habits, because osteoporosis medications such as Fosamax and Evista are only for women after menopause.
"We don't know the effects of these medications on a woman of child-bearing age -- or a baby," says Dr. Cosman. However, your doctor may do blood tests to help pinpoint a treatable cause of your brittle bones, such as a vitamin D deficiency.
A commitment to building bones can pay off, as Lynette Duncan of Fayetteville, Arkansas, can attest. When she was 26, she signed up for an osteoporosis study out of curiosity, and was surprised to find that her spine and hip bone-density scores fell in the osteopenia range.
"I pictured myself as a hunched-over old woman, so I started taking calcium and D supplements and stepped up the strength training," says Duncan. A bone-density scan two years later showed she'd regained bone in her hip, and maintained it in her spine. "I intend to stay as healthy as possible so I can keep up with my daughter as she grows up," she says.
Rachelle Vander Schaaf, a mother of two, lives in eastern Pennsylvania.
Originally published in American Baby magazine, May 2005.