How to keep your bones healthy throughout each stage of life

Unless a bone is broken, it is easy to forget about the fundamental structure supporting our entire body that we cannot see: the skeleton. Yet a skeleton and its bones are integral to our daily life, serving a variety of functions including protecting vital organs, serving as attachment points for muscles, storing minerals, producing bone marrow and more. To bring awareness to Bone & Joint Health Week, we will dive into our own body’s foundation and explore how it changes as we age, as well as how to protect it.

Bones are often thought of as static, unchanging structures, but in reality, bones are constantly changing and developing throughout one’s lifespan. Our 206 bones all have unique shapes and structures, though the general anatomy of bones is fairly consistent. There are two main types of bone, cortical and trabecular. Cortical bone is the hard outer layer that contains the highest calcium concentration, while the trabecular bone is found below the cortex and is made up of a honeycomb-type structure full of bone marrow and fat stores.1 As we age, the size, mineral content, density, and durability of our bones changes considerably.

0-10

Childhood and adolescence are incredibly important periods for bone growth and development. As children grow, their bones accumulate calcium deposits that lay the foundation for bone health long term. Therefore, it is vital for children to get an appropriate amount of calcium and vitamin D in order to promote bone growth as they age. According to the National Institute of Health, products such as milk, cheese, tofu, and yogurt are all excellent examples of foods with high calcium content. Protein is also a key factor, as it improves calcium absorption. In addition to ensuring children have proper nutrition, participation in high impact activities such as jumping, running, and playing sports is also vital to promote healthy bone development.

10-20

As children reach puberty, bone growth surges. Peak growth rates, aka growth spurts, tend to happen around age 11–12 for girls and age 13–14 for boys. Growth spurts start earlier for girls as the onset of menstruation brings a jump in estrogen, which promotes calcium absorption and an increased in bone mineral density.2 As puberty comes to an end, the growth plates close, signaling the completion of this phase of growth and development. This is not, however, the end of the journey for bone development.

20-40

In the years following adolescence, calcium deposition continues at a much higher rate than absorption. The American Academy of Orthopedic Surgeons states that peak bone mineral density occurs between age 25–30 for most individuals. As we get older though, the rate of bone deposition decreases and rate of calcium absorption increases, which means we begin to lose bone density gradually over time. This breakdown rate begins to creep up with age, with a sharp increase for women around menopause. In order to decrease the amount of bone loss, it is crucial to maintain the health of your bones during your earlier years through physical activity such as weightlifting and proper nutrition, including a generous intake of calcium, vitamin D and protein.

45-60

Just as an increase of estrogen improved calcium absorption in adolescence, the drop in estrogen associated with menopause negatively impacts a woman’s calcium stores. As calcium stores deplete, bone mass diminishes, with the average woman losing around 10% of bone mineral density in the first five to six years of menopause.3 As this process progresses, the risk for osteopenia and osteoporosis significantly increases.

>65

Though the effect is not as drastic, men are also at risk for developing osteoporosis. On average, by the age of 65–70, men are losing bone mineral density at the same rate as their female counterparts. As the rate of bone density decreases, the risk of fracture tends to increase. The American Academy of Family Physicians recommends that women over 65 and men over 70 get a bone density test (DEXA scan) as a preventative measure to identify their risk of osteoporosis.

Though a certain amount of lost bone mineral density is normal, there are many modifiable behaviors than can delay or slow down this process that can be implemented at any age. Smoking, alcohol use, and excessive caffeine consumption have all been identified by the NIH as risk factors for increased loss of bone mineral density as one ages. Other important factors to consider are calcium intake and physical activity. As mentioned above, calcium and vitamin D recommendations change throughout the lifespan, but are particularly important during childhood and after age 50 for women and age 70 for men.

Exercise can also have a huge impact on bone health. For those between the ages of 20–50, studies have shown that individuals that participate in moderate to high intensity impact activities have a greater average bone mineral density than those who are less active or who participate in lower impact activities. Though aerobic activities such as biking, swimming, and running are great for maintaining a healthy cardiovascular system and have a number of health benefits, these activities may not put enough load on the skeletal system to promote increased bone deposition. Resistance training has been shown help build muscle, increase bone density, and decrease fall risk. The Mayo Clinic recommends weight-bearing resistance training for those with or at risk for osteoporosis to optimize bone health and decrease risks associated with having decreased bone mineral density. This should, however, be done with close supervision and modification by a medical or fitness professional to ensure exercises are safe and dosed appropriately.

Our bones go through many changes as we progress through our lives, but there are a myriad of ways that we can help promote and support bone health in every stage of life. Lifestyle choices, exercise, and nutrition all have an enormous impact on our skeletal system. Take the extra time to invest in your health and support your bones; your skeleton will thank you!