Healthy Bones for Life
Every day you make choices that could build strong healthy bones, or put your skeleton at risk of breaking down. Our osseous tissue is pretty remarkable stuff. The living tissue that makes up our bones is a dynamic system that is constantly breaking itself down and rebuilding itself. Our skeleton supports our body, protects our organs, allows movement thanks to the attached skeletal muscles, stores minerals and fat, and is the location where our blood is made. While genetic factors, age, and disease all play a role in bone health, weather you have a frail or strong skeleton is largely in your control. We all want our bones to stay strong so we can continue to live active healthy lifestyles. Here I discuss five habits for healthy bones that you can practice every day.
Lifestyle Habits for A Strong Skeleton
1. Stay Active
The link between physical activity and bone mineral density is one of the most studied aspects of bone health. Numerous studies have provided evidence that physical activity, of any kind, promotes healthy bones (Hammad, 2017; Hirota, 1992; Office of the Surgeon General, 2004; Stillman, 1987). Athletes are known to have the greatest bone density, but even middle age and elderly women can improve their bone density and reduce bone loss with weight-bearing exercise (Smith, 1986).
Although exercise is important for bone health at any age, childhood physical activity appears to have the most important and long-lasting effects. One study that looked at 101 healthy female volunteers age 20 to 35 years old found that of all the lifestyles factors considered, only physical activity during childhood had a significant positive effect on bone density (McCulloch, 1990). The human body is constantly breaking down and rebuilding bone tissues. During childhood the rate of bone building happens faster than the rate at which bone is broken down. But after age 30 the tables turn and the body begins breaking down bone tissue faster than the rate at which it builds new bone tissue. This is the primary reason why it is critically important for children and adolescents to build strong bones so that there is enough extra bone mass to make up for the deficit that will accumulate in the later years. Think of it as bone cells in the bank. We are much better at stacking up bone cells in our bone bank when we are young and when we are older we will start to spend those extra cells. If we haven’t built up enough extra bone mass in our bone banks, we are at greater risk for bone diseases and fractures as we age. It is now widely accepted that physical activities performed during childhood, especially those which apply large force or are weight bearing, equate to benefits in bone mass, size, and structure that persist for many years beyond the time when the activity happens (Gunter, 2012).
2. Get Your Sunshine Vitamin D
Vitamin D, the sunshine vitamin, is important for bone health because it aids in the absorption and utilization of calcium. Low vitamin D levels are associated with bone loss and increased fracture risk (Hammad, 2017). The main source of vitamin D for most people is sunlight, so getting outside each day is an important part of maintaining healthy bones. Factors that can limit sun exposure, and thus put you at risk for inadequate vitamin D levels, include where one lives, access to outdoors, amount of clothing covering the body, skin pigmentation, sunscreen, and age. Research indicates that just 9 minutes of lunch-time sun a day is sufficient for Caucasians to manufacture enough vitamin D, while those with darker-pigmented skin will need more time in the sun each day (Smith, 2019). Too much sun can be damaging to the skin, especially for those with lightly-pigmented skin. The best way to ensure proper vitamin D exposure is to have periodic blood tests to make sure you are within the target range.
3. Eat the Rainbow of Plants
The best diet for building strong bones consists of a variety of nutrient-dense fruits, vegetables, seeds, nuts, and legumes. Many people today believe that simply drinking milk and eating dairy ensures they will have strong bones, but there is much more to the strong skeleton story. While we’ve all heard calcium builds strong bones, just how much calcium intake effects bone density is still a subject of debate. A 1990 meta-analysis that included 49 studies found that calcium intake consistently prevented bone loss in postmenopausal women, but that the effect was greatest when women started out with low calcium intake. Their analysis showed a small positive correlation between calcium intake and bone mass (Cumming, 1990). Twenty-five years later, a 2015 meta-analysis that included 59 eligible randomized controlled trials, which studied calcium intake in relation to bone density, found similar results. The studies demonstrated that increased calcium from dietary sources or supplements increased bone density in the spine and neck by 0.7-1.8%. The impact on the hip and total body was slightly less (0.6-1%) and there was no effect on the forearm. The study’s authors concluded that:
“Increasing calcium intake form dietary sources or by taking calcium supplements produces small non-progressive increases in BMD, which are unlikely to lead to a clinically significant reduction in risk of fracture.”(Tai, 2015).
While evidence does not support the hypothesis that larger intakes of calcium equates to increased bone density, there is evidence from these studies and others that calcium deficiency plays a role in bone loss (Hirota, 1992; McCulloch, 1990).
Calcium may have been the recipient of the lion’s share of accolades for bone protection, but it is far from alone among nutrients important for building strong bones. Along with calcium and vitamin D, many other nutrients can affect bone health in a positive or negative way. Phosophates make up more than half the mass of our bones and about 85% of the body’s phosphorous is found in the skeleton. Too much or too little phosphorous can put our bone health at risk (Heaney, 2004). Magnesium influences the growth of hydroxyapatite crystals, the mineral compound found in bones. Other micronutrients that are vital to healthy bones include vitamin K, vitamin C, copper, manganese, zinc, and iron. These nutrients are all essential for proper function of enzymes related to forming new bone matrix (Office of the Surgeon General, 2004).
The best way to ensure you are getting sufficient amounts of calcium and other vitamins and minerals necessary for maintaining a strong skeleton is to eat a nutrient-dense diet of whole plant foods. Whole grains, dark leafy greens, seeds, nuts, beans, and soy-based foods are all excellent sources of dietary calcium and iron. Eating a variety of fresh fruits, vegetables, seeds, nuts, and legumes will ensure you are getting the full array of vitamins and minerals needed to build strong bones.
4. Maintain a Healthy Weight
Maintaining a healthy body weight is key to maintaining skeletal health. According to the U.S. Office of the Surgeon General,
“Body weight and pubertal development are the most consistent predictors of bone mass in adolescents. Fear of fat and obsession with thinness among pre-teen and teenage girls frequently translates into diets that fail to meet their caloric, calcium, and protein needs” (2004).
A study of premenopausal women in San Francisco who were between 90-150% of their ideal weight measured the women’s cognitive eating restraint (CER) using questionnaires on weight history, body size satisfaction, dieting history, and eating behavior. Women with a higher CER score, meaning they were more likely to restrict their food intake, had significantly lower bone mineral content than women who were more satisfied with their body and who did not restrict their food intake (Loan, 2000). Low body weight, skipping meals, and frequent dieting are all associated with decreased bone mineral density (Hirota, 1992; Office of the Surgeon General, 2004).
5. Refrain from Smoking and Soda
To keep your skeleton strong, it’s best to stay away from smoking and soda. Smoking can reduce bone mass and increase fracture risk, in addition to other negative health effects. The damage smoking inflicts on bone health is multifaceted. Smoking appears to have a direct toxic effect on bone cells, can lower calcium absorption, alters the body’s handling of vitamin D, and can contribute to weight loss and reduced physical activity (Office of the Surgeon General, 2004).
Smoking isn’t the only substance specifically linked to bone loss. Drinking soda has been linked to decreased bone density and increased fracture risk. A study of 101 young Saudi females found that high soft drink intake was positively associated with reduced bone mineral density (Hammad, 2017). Another study of 275 adolescent girls in the United Arab Emirates found that soda drinking was associated with a decreasing level of blood calcium and an increasing loss of calcium in the urine, which the researchers hypothesize may lead to osteoporosis later in life (Mahmood, 2008). In 2014 researchers analyzed data from the Harvard Nurses’ study including 73,572 postmenopausal women and found that each additional serving of soda per day increases a woman’s hip fracture risk by 14% (Fung, 2014).
The choices we make every day influence whether our skeleton is frail or strong. There are so many reasons to give thanks for strong bones and it’s good to know that maintaining healthy bones is largely within our control. Getting plenty of exercise and sunshine, eating a nutrient-dense diet, maintaining a healthy weight, and steering clear of smoking and soda will help keep your bone’s mineral bank well-stocked and your skeleton strong.
BONUS! For a fun look at the skeletal system to enhance your osseous tissue appreciation, check out this video from Crash Course Anatomy & Physiology.
REFERENCES: 1. Fung, Teresa T, Meredith H Arasaratnam, Francine Grodstein, Jeffrey N Katz, Bernard Rosner, Walter C Willett, Diane Feskanich. “Soda consumption and risk of hip fractures in postmenopausal women in the Nurses’ Health Study.” The American Journal of Clinical Nutrition, vol. 100, no. 3, 2014, pp. 953–958, https://doi.org/10.3945/ajcn.114.083352 2. Gunter, Katherine B., et al. “Physical Activity in Childhood May Be the Key to Optimizing Lifespan Skeletal Health.” Exercise and Sport Sciences Reviews, vol. 40, no. 1, 2012, pp. 13–21., doi:10.1097/jes.0b013e318236e5ee. 3. Hammad, Lina F., and Nada Benajiba. “Lifestyle Factors Influencing Bone Health in Young Adult Women in Saudi Arabia.” African Health Sciences, vol. 17, no. 2, 2017, pp. 524., doi:10.4314/ahs.v17i2.28. 4. Heaney, Robert P. “Phosphorus Nutrition and the Treatment of Osteoporosis.” Mayo Clinic Proceedings, vol. 79, no. 1, 2004, pp. 91–97., doi:10.4065/79.1.91. 5. Hirota, T, et al. “Effect of Diet and Lifestyle on Bone Mass in Asian Young Women.” The American Journal of Clinical Nutrition, vol. 55, no. 6, 1992, pp. 1168–1173., doi:10.1093/ajcn/55.6.1168. 6. Loan, Marta D Van, and Nancy L Keim. “Influence of Cognitive Eating Restraint on Total-Body Measurements of Bone Mineral Density and Bone Mineral Content in Premenopausal Women Aged 18–45 y: a Cross-Sectional Study.” The American Journal of Clinical Nutrition, vol. 72, no. 3, 2000, pp. 837–843., doi:10.1093/ajcn/72.3.837. 7. Mahmood, Mona, et al. “Health Effects of Soda Drinking in Adolescent Girls in the United Arab Emirates.” Journal of Critical Care, vol. 23, no. 3, 2008, pp. 434–440., doi:10.1016/j.jcrc.2008.06.006. 8. McCulloch, R G et al. “Effects of physical activity, dietary calcium intake and selected lifestyle factors on bone density in young women.” CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne vol. 142,3, 1990, pp. 221-7. 9. Office of the Surgeon General (US). Bone Health and Osteoporosis: A Report of the Surgeon General. Rockville (MD): Office of the Surgeon General (US); 2004. 6, “Determinants of Bone Health. “ Available from: https://www.ncbi.nlm.nih.gov/books/NBK45503/ 10. Smith, Everett L., and Diane M. Raab. “Osteoporosis and Physical Activity.” Acta Medica Scandinavica, vol. 220, no. S711, 1986, pp. 149–156., doi:10.1111/j.0954-6820.1986.tb08944.x. 11. Smith, Nikki. “Getting Enough Vitamin D? You Need Far Less Sun than You Might Think.” Cancer Research UK - Science Blog, 21 June 2019, scienceblog.cancerresearchuk.org/2018/08/06/getting-enough-vitamin-d-you-need-far-less-sun-than-you-might-think/. 12. Stillman, R. J. “Physical Activity and Skeletal Health: A Brief Survey.” Sports Women Medicine and Sport Science, 1987, pp. 1–12., doi:10.1159/000414155. 13. Tai, Vicky, et al. “Calcium Intake and Bone Mineral Density: Systematic Review and Meta-Analysis.” Bmj, 2015, doi:10.1136/bmj.h4183.
