Strong Women, Strong Bones

Strong Women, Strong Bones by Miriam E. Nelson, Ph.D. ISBN 0-399-52656-0

Right up front we're going to say that this is a great book. We've spent a fair amount of time researching and studying up on osteoporosis, and we still learned things from this book. Nelson, who is an associate professor of nutrition and the director of the Center for Physical Fitness at Tufts University, is clearly gifted with a teacher's ability to take a complex subject and break it down to graspable elementals.

We're not going to give you the content of the book, but we will tell you a little bit about why you should read it if you're in menopause, irrespective of your hormonal status and personal risk factors. To begin with, as she points out, one in three women develop osteoporosis and more women die of its complications every year than are killed by, say, breast cancer. This really is a life or death matter, and if you're sitting with two of your women friends, the odds are substantial that it's your life or death we're talking about.

Anyone who reads this website and our discussion forums should realize pretty quickly that we feel that understanding the mechanism behind things helps us figure out what to do. So we were gratified to see an excellent discussion of how bone is made and how hormones and what happens to them with menopause impact this process. In very simple terms, our bodies use calcium to tune our systemic acid/base balance, and any time that's off, we scavenge a bit of bone for the calcium it contains. That is the fundamental reason why we never get "ahead" with bone maintenance: we need to consume a steady supply to keep up. And did you know that not only does estrogen affect the bone-building cells themselves, but our ability to absorb the calcium we eat from our intestines? And that stress, which causes our cortisol (the stress hormone) to rise, also can harm our bones by directly limiting those estrogenic effects? If you've read other stuff on this site about how cortisol and our ovarian hormones intersect in actions, this may slot neatly into that knowledge because, yes, it's all inter-related.

How much difference does menopause really make? Nelson says:
Without estrogen to contain them, the bone-dissolving osteoclasts increase their activity by about 20 percent; the osteoclasts don't increase to match. The net effect is loss of bone. Menopausal women typically lose 1 to 3 percent of their bone mass annually, and some lose as much as 5 percent.
That doesn't sound like a terrifically high number, but when you think about a loss of 3 percent over just three years, that's nearly 1/10 of your total bone gone. And because bone strength depends upon the structure of the bone, not just its total weight, that represents a huge loss of the ability to survive the wear and tear of daily life.

After some introductory material presenting the basics on osteoporosis, most of the book is on specifics. She discusses risks and how to evaluate your own personal risk degree based on both history and lifestyle, including a surprising number of other medications you might be taking. She explains testing and how often and when we should be tested. She also includes instructions on how to test yourself for one critical aspect of bone preservation: balance and your ability to avoid falling. Think you don't have any problems with this? Try her tests and be surprised—we were.

This book was printed in 2000, which means it was written a year or two before that. While most of the material it contains is perfectly pertinent and up to date, there are a few areas where current research and medical thinking has moved on. Her section on calcium is excellent in terms of discussing food sources, supplements and the need for vitamin D to be able to utilize calcium. But her recommendations for vitamin D amounts are looking a bit outdated. Today doctors tend to focus on around 2000 IU for daily intake, varying according to sun exposure (an outdoor gal in Florida isn't going to have quite as high a need as a desk jockey in Alaska, and we almost all need a bit more in the winter than summer). That aside, her material on things like interactions (how bad is that soft drink for you really?) goes a long way towards giving us solid information on what happens to the calcium we eat and how to make best use of it. And for those who don't really want to take supplements, she provides tools and guidelines on how to maximize and calculate dietary calcium intake so you can get a clear picture of where you are and how to get to where you should be.

A large part of her book is devoted to exercise and why it's critical to both preserving and restoring our bones. According to her, it takes either the shock action of impact or the stress of strong muscles pulling against bones to provide the stimulus for our bodies to maintain bone strength. She divides the necessary components of a bone maintenance program into three elements: weight-bearing aerobics, strength, and balance. In each section, she provides ranges of activities appropriate for those anywhere from strong-boned to osteoporotic.

In terms of weight-bearing, this can be anything from jumping (recommended for non-osteoporotic women) to brisk walking (for those with already diminished density). She is clear that only exercises that transmit action through our spine and hips are effective--bicycles, rowing, swimming: these kinds of things may provide cardiovascular fitness but they do not affect bones. She is equally clear that while gentle walking is better than none at all, it fails to provide enough challenge to bones to create significant density improvement.

Strength training is the most likely to actually boost density. This is not just opinion on the author's part--she's participated in research that demonstrates greatest density gain when this is included in a bone maintenance program. As with each of the three workout segments, she gives specific exercises and directions on weights to begin with and how to step them up over time. That's right: we have to keep challenging our bodies over time. To involve the proper amount of stress, exercises must be difficult enough that the muscle groups involved can perform only eight repetitions before becoming fatigued. Just as aerobic training that doesn't work us hard enough to raise our heart rate isn't of use, so strength conditioning doesn't work unless it's also hard work.

The third portion of her workout focuses on balance. Here, the intention is bone-protective through reducing our risks for falls. If our sense of balance is well-developed and the muscles we need to maintain our balance are prepared to undertake the task, we are less likely to damage our weakened bones by falling. Those who are not suffering from bone loss yet may scoff at the need for this, but her point is that bone loss is part of our expected aging experience and making balance tactics ingrained early means they are in place to automatically protect us when we do come to need them.

This book also goes into the range of medications available to treat or prevent osteoporosis. Unfortunately, this is the other main area where the book is dated. Written before WHI and increasingly conservative attitudes amongst doctors towards prescribing hrt, she is a little more casual about estrogen use for maintaining bone density than is the norm today. While osteoporosis continues to be an FDA-recognized reason for prescribing estrogen, many doctors feel that the breast cancer risks, although lower than overall osteoporosis risks, are adequately compelling that they do not wish to be liable for prescribing hrts for bone maintenance. Nonetheless, the major medical consensus groups all stop short of denying that osteoporosis treatment or prevention are acceptable reasons to continue taking hrt.

While the book does spend some time favorably commenting on bisphosphonates, which are specifically used to treat osteoporosis, she is writing before the recent publicity, still not widely distributed within the medical community, of the risk of jaw osteonecrosis and atypical fractures as side effects of the bisphosphonates, even when administered in oral form. This risk has caused some questioning of the strategy of "fossilizing" bones, suggesting that treating density rather than actual bone strength restoration is treating the test rather than the patient. It's outside our purpose here to open up the arguments around bisphosphonates and the influence of pharmaceutical company economics on health care decisions, but more information on these topics can be found in our bookmarks account with the tag "osteoporosis."

Despite the concerns we have about these dated sections (and for which updated information is readily available online), we would still say that this is the best reference on the topic we have found to date, both highly readable and eminently practical.