May 28, 2020

All of us who have had a friend or a family member who's suffered a broken hip from thin bones worry about how to protect our own bones.

A fragility fracture is a broken bone that occurs from forces that wouldn't have caused a fracture in bones that are normally strong. We think of them as broken bones, usually in the hip, the top of the thigh bone that attaches to the pelvic bone, the wrist, or fractures in the vertebral column that make the building blocks of the vertebrae scrunch a little flatter, causing curvature of the spine. "Scrunch" isn't a word that bone experts would use, but it sort of fits.

Populations That Are Susceptible to Fragility Fractures

So bones get thinner and are less strong as we age, and women have thinner bones than men. White and Asian women have thinner bones than African women. One in three white women and one in five white men will have a fragility fracture in their lifetime. For elderly men and women, about one half who suffer a fragility fracture of the hip will no longer be able to live independently. So this is a big medical and social problem costing billions of dollars each year in medical and assisted living expenses and the social costs of loss of independence.

Now, there's a lot of heat but not much light on what we, as middle age women, can do to keep our bones strong. So things we can't change, we can't change our genetics, that includes our sex. Women have thinner bones at peak bone density than men. Our race, African women have denser bones than white women.

And we can't change our genetic risk for osteoporosis. Some are just born with thinner bones. We can't change our medical history. Some of us have diseases such as asthma or rheumatoid arthritis or other diseases that are treated with corticosteroids, which are drugs that work miracles for some diseases, but cause bone thinning. Luckily, these days there are increasingly alternatives to steroids, and there are other medications that cause thin bones.

Bone Strengthening Behavior

We can change our behavior. If we are young, we should try to reach our peak bone density, which comes in our mid-30s, with the strongest bones that our nature will give us. That means that when we went through childhood and early adulthood being active, eating a balanced diet with adequate calcium, and getting outside to get our vitamin D.

Now, I'm not sure what the future holds for a generation of kids who grew up inside, in front of video screens. If we are smokers, we should have stopped a long time ago. Smoking makes for thin bones, but it's only one of the many more diseases, more deadly than thin bones that's caused by smoking. Drinking alcohol in excess also causes thin bones, and it makes people fall down. So if we are in midlife, poorly defined, but I picked 45 to 65, and we cannot make our bones much stronger, and we do want to keep our bones from getting thinner, what works?

Well, there's a lot of disagreement among health professionals about what works and what doesn't work to keep bones denser. And while we measure it, part of how we measure it is the problem. We can measure bones' density but that doesn't always equate to bone strength. Some dense bones are brittle and break. We don't have a good measurement of bone strength.

Many studies of treatments to prevent osteoporosis fractures look at bone density as an endpoint, but what we really want to know is does this intervention decrease fractures? So what doesn't work? Calcium supplements for women eating a standard American diet does not increase the risk of fractures. This has been shown in large randomized trials that were part of the Women's Health Initiative, a huge study on what works and doesn't work for women's health as they get older. That doesn't mean you don't need calcium, you just need a balanced diet.

Vitamin D supplements don't work. An analysis of 23 studies that were randomized, and randomized middle aged people to varying amounts of vitamin D showed no difference in bone density in those taking vitamin D compared to placebo. Even when Vitamin D is suggested, the amount suggested varies. The American suggest 800 to 1,000 international units of vitamin D per day for middle aged people, and the British recommend 400. That doesn't mean that people who are truly vitamin D deficient, as measured by vitamin D levels, shouldn't take supplements. But people who are, are home-bound and never see the sun will be vitamin D deficient, but they're also at risk for fragility fractures because they're sick and frail with respect to their muscles and their balance.

Exercise doesn't work to change bones' density much. We recommend weight bearing exercise because we know astronauts and bedridden people lose bone density, but for the average person, exercising just to build bone density doesn't make a big difference. Now, that doesn't mean the exercise doesn't decrease bone fractures. It could be that people who cannot exercise have more fragile bones because they don't move at all, or they don't eat or they drink too much alcohol or they have one of the many factors that make them frail and more likely to have a fragility fracture. But for people who can exercise, adding more to increase bone density doesn't make a difference in bone density.

Exercise for Bone Strength

We do know that people who exercise have fewer fractures. Maybe exercise makes stronger bones, bones that are more resilient, and maybe, most importantly, exercise makes us less likely to fall. This has been shown in small randomized trials of tai chi and yoga, both of which have a lot of balance work. The British National Health Service actually recommends getting outside in the sun. The sun never shines in Britain, of course. The Americans don't recommend that so strongly, but getting out means also moving a little, both of which are good.

Testing and Treatment to Slow Bone Thinning

So what should we do? We should know our own medical history. And if we have risk factors of prolonged immobility, corticosteroid use, or other factors, we should get our bone density measured earlier than 65 years of age. The recommendation from the Preventative Services Task Force recommends bone density testing at 65 for the average woman without other risk factors. If you already have osteoporosis, there are medications that can slow bone thinning, and some can increase bone density, and some have been shown to decrease fracture risk.

We should stop smoking, limit drinking to more than one drink a day, get out and move every day, and exercises that include balance will decrease the risk of a fall. We should eat a balanced diet. We should talk to our health care providers about medications that we take that may increase the risk of bone thinning, like corticosteroids, or falling, like sleeping pills and some anti-anxiety medications.

We should know if there's something about our health, diet, or habits that make us at risk for thin bones or falls, and intervene to make it better. Of course, if you want to add a calcium supplement or a vitamin D supplement in small doses, it most likely won't hurt anything but your budget, and you can save by not buying that extra bottle of wine.

updated: May 8, 2020
originally published: August 3, 2017

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