Most people understand that nutrition affects bone health. In fact, many are aware that calcium is critical for building healthy bones and preventing osteoporosis later in life. What may be less apparent is that in addition to calcium, a constellation of nutritional and lifestyle factors influence the health of bones. Knowing the array of factors that affect bone health will help stave off osteoporosis and maximize skeletal health. In It for the Long HaulOsteoporosis is a condition of gradually weakening bones, also known as "brittle bones disease." "One in every four women will likely develop osteoporosis later in life," asserts Purdue University professor of foods and nutrition, Dorothy Teegarden, PhD. In fact, the National Osteoporosis Foundation estimates that 10 million Americans have osteoporosis—two million men and eight million women—and that an estimated 34 million are at risk of osteoporosis because they already have a low bone mass. Over time, bones lose calcium and other minerals, which can leave the bone structure fragile and porous. Protecting and supporting skeletal health, therefore, are lifelong tasks requiring vigilance well into the mature adult years. It is never too late to implement lifestyle changes that can help maintain bones for a lifetime therefore, paying attention to our diet and lifestyle when we are young and as we age is important.
Top Ten Ways to Protect Your Bones:
1. Continue Being Calcium Conscious. Calcium is the most recognized nutrient for bone health for a reason. Calcium is the chief bone-forming mineral. Most of the calcium that we consume can be found in the bone—99 percent of the body’s stores to be exact—can be found in our bones. It is a major requirement for adequate bone growth early in life and studies have shown that early intake prevents bone loss later in life.
As with all living tissue, bones are in a constant state of change. Calcium gets deposited and withdrawn from the bone structure on a daily basis to help support other body functions. Bones get stronger and denser as more calcium becomes part of the bone structure, or the bone matrix. In fact, bones can store additional calcium for days when calcium consumption comes up short. “Adults need 1,000 mg [milligrams] of calcium daily, while adolescents need 1,300 mg,” says Dr. Teegarden, “about three to four servings of low-fat dairy daily can be consumed to meet this target.” Dr. Teegarden highlights skim milk, one percent milk, yogurt, and cheese as great options, as well as lactose-free milk products and calcium-fortified beverages, such as orange juice, for those with lactose intolerance.
2. Complement Calcium with Vitamin D. An American Journal of Clinical Nutrition bone health review by noted bone health researcher, Robert P. Heaney, M.D., John A. Creighton University Professor, described vitamin D and calcium as a “partnership.” Vitamin D and calcium work together to promote bone growth, reduce loss with age and decrease the risk for fractures. Vitamin D helps us get the most out of the calcium that we consume by improving the efficiency of calcium absorption. “Vitamin D facilitates calcium’s absorption,” agrees Rachel Johnson, PhD, RD, professor of nutrition and dean of the College of Agriculture and Life Sciences at the University of Vermont. Additionally, the combination of vitamin D and calcium appears to reduce excess breakdown and repair, also known as bone remodeling. Breakdown and repair are necessary, but they appear to increase with age leading to bone fragility. Low levels of vitamin D are associated with an increased risk of hip fracture, especially in elderly individuals.
Experts cite low vitamin D intake as an emerging worldwide public health issue for people of all ages. “There’s growing support that the current recommended intake for vitamin D is too low,” warns Dr. Teegarden. The adequate intake (AI) required to maintain adequate levels of vitamin D in blood is 200 IU/day for people under 50 years of age, 400 IU/day for those 51 to 70 years of age, and 600 international units (IU)/day for individuals over age 70 years. Vitamin D can be found in fortified milk, fatty fish (like cod liver oil, mackerel, sardines, salmon, and tuna), some vegetable oil spreads, fortified cereals, fortified orange juice, egg yolk and some cheeses. Supplements and multivitamins may also contain vitamin D, however the consumption of amounts greater than 2,000 IU/day could become a potential health risk; check the label on your multivitamins to make sure that you do not exceed this amount.
The major source for vitamin D—the sun—cannot be found in your local grocery store. The UV rays from the sun trigger the skin to produce vitamin D. Overexposure to the sun is a known health risk; however, exposure of the hands, arms, and face to sunlight for 10 to 15 minutes twice weekly for adults who have medium skin tone and who do not burn easily in the sun should be adequate to allow the synthesis of the necessary amounts of vitamin D. People with darker-pigmented skin and those living in areas with reduced exposure to sunlight may not synthesize enough vitamin D from the sun, therefore look for vitamin D sources in the diet.
3. If You Don’t Use It, You Lose It. Studies have shown that weight-bearing exercises, like walking, jogging, dancing, or even marching, help to strengthen your bones. Strength training is recommended to stabilize and secure bones and even simple activities have been shown to provide big gains in bone strength. The American College of Sports Medicine’s (ACSM’s) position on physical activity and bone health describes impact activities, that is, weight-bearing activities, as well as strength training as ideal forms of exercise for your bones. For growing bones in kids, they recommend participating in intense weight-bearing activity for at least 10-20 minutes at least three times per week and note that such activity two times a day is even better. To help maintain bone health throughout adulthood, ACSM advises adults to engage in weight bearing activity, such as tennis, stair climbing, jogging, walking, or activities that involve jumping, like volleyball or basketball, along with strength training. To optimize bone health, adults are advised to do weight-bearing exercises three to five times per week and strength training two times per week for at least 30 to 60 minutes.
4. More Minerals: Magnesium and Phosphorus. Magnesium and phosphorus are required for bone mineral metabolism. Low magnesium levels are associated with low bone growth, osteopenia (osteopenia refers to a bone mineral density [BMD] that is lower than the normal peak BMD but not low enough to be classified as osteoporosis), bone fragility, and calcium loss. Phosphorus, on the other hand, is necessary for bone health; but too much phosphorus in the diet can be of concern, especially if excess phosphorus is coupled with a low calcium intake. Consuming adequate magnesium from halibut, tuna, artichokes, grains, nuts, and dairy products can help you manage or balance your phosphorus intake. Eat a varied diet, and make sure that you eat enough calcium-containing foods.
5. Vital Vitamin: Vitamin K? The evidence is still developing, but it appears that inadequate intakes of vitamin K have ill-effects on bone density and may result in the risk of bone fracture. The solution is to eat a variety of fruits and vegetables, such as spinach, tomatoes, lettuce, cauliflower, broccoli, cabbage and soybeans to maintain adequate levels of vitamin K in your body. Talk to your doctor before you increase your intake of vitamin K if you are taking certain blood-thinning medication.
6. Protein. Protein has developed a reputation for having a negative influence on bone because high-protein diets were associated with an increase in urinary calcium loss. Not all studies have confirmed this finding, and some have shown that high-protein, calcium-rich diets may be beneficial to bone growth. In addition, protein is necessary for healthy bone structure and for the production of bone growth-promoting hormones. Evidence points to the need for the inclusion of adequate amounts of protein in the diet (the Recommended Dietary Allowance is 0.8 grams per kilogram (or .36 grams per pound) of body weight per day for most adults).
7. Go Low with Saturated Fat. We know that too much saturated fat is bad for your heart, and now evidence suggests that it could also be bad for your bones. According to the findings from the third National Health and Nutrition Examination Survey, a large nationwide survey of Americans, people who consumed a diet high in saturated fat had significantly lower bone mineral densities. Interestingly, other researchers have found that the essential fatty acid omega-3—whose reputation precedes it as a heart-healthy option—may positively influence bone health. Researchers found that plant sources of omega-3 fatty acids protect bone and decrease bone tissue turnover. Therefore, continue your heart-healthy diet consisting of low levels of saturated fat (i.e. choose lean meats and low-fat or nonfat dairy products), choose walnuts, flaxseed, and salmon; and use vegetable oil blends rather than butter to get omega-3 fatty acids in your diet.
8. What about Caffeine and Carbonation? “Neither caffeine nor carbonation, by themselves, has a significant effect on bone health,” remarks Dr. Heaney. They become an issue when they displace milk or calcium sources, so do not feel guilty about adding milk to your morning coffee.
9. Smoking: Quitting is Key. The National Institutes of Health (NIH) has stated that smoking has been linked to compromised bone health. Jeffrey Hampl, PhD, RD, of the Department of Nutrition at Arizona State University concurs, “the damage to bones thanks to smoking may be collateral.” “In other words,” describes Dr. Hampl, “a number of studies have shown that smokers tend to have poor diets (including less calcium and vitamins D and K, which are needed for strong bones).” Hampl adds that smokers also tend to be leaner than non-smokers. They therefore have less weight and hence, they have reduced weight pushing against their bones. In addition, there is evidence that smokers are less physically active than non-smokers, supporting Hampl’s and the NIH’s concern that smoking is part of a cluster of poor health behaviors, which can have a negative impact on bone health. Experts agree that quitting smoking is key and that smoking cessation success is significantly improved when you seek help….don’t go it alone.
10. Last, but Not Least: Eat a Balanced Diet for Overall Health and Wellness. “The 2005 Dietary Guidelines for Americans are the best health plan to follow for both bone health and for overall health,” advises Connie M. Weaver, PhD, distinguished professor and head of the Foods and Nutrition Department at Purdue University. The Guidelines recommend three servings of low-fat dairy products per day, ample amounts of fruits and vegetables , and exercise. As it turns out, Dr. Weaver says that these recommendations support health in other ways—namely, by possibly reducing the risk of cancer and heart disease, along with maintaining gastrointestinal health, protecting yourself from heart disease, and much more. The bottom line is that diet and lifestyle choices affect bone health. By choosing a diet rich in calcium, vitamins D and K, and magnesium, combined with an active, smoke-free lifestyle, you can protect your bone mass through a lifetime. To assess your risk for osteoporosis, see the National Osteoporosis Foundation’s Osteoporosis: Can It Happen to You? risk factor questionnaire at: http://www.nof.org/prevention/Risk_Factor_Questionnaire.pdf .
Michelle, your blog is very well thought out and informative. It is so important to find natural ways of adding to bone health. Raw leafy greens, such as bok choy, kale, and broccoli, have a the richest source of calcium per calorie.
I'm glad you mentioned the importance of exercise, especially those consisting of weight-bearing activities. Examples of said weight-bearing exercises can be found on my