iv: Our Editor in the Field
The Royal Osteoporosis Society This month, we asked the experts at the Royal Osteoporosis Society to brief us on what we need to know about bones. Here’s what we learned:
Every minute of every day, someone somewhere suffers a bone fracture, due to osteoporosis. Yet, because of under-diagnosis, under-treatment, and low public awareness, it is still often referred to as ‘the silent disease’. Common misconceptions persist— that shrinking bodies are just a normal part of getting older, that osteoporosis only affects women, that bones are lifeless and unchangeable. None of this is true. In fact, we all can and should take positive steps to build our bone strength and prevent osteoporosis and broken bones. Bone health affects everyone and it can be acted upon at any age. The Royal Osteoporosis Society is working to turn up the volume on bone health and highlight that it’s never too early to start looking after your bones. There are 206 bones in the human body. Our skeleton works to support the body, protect our vital organs, help the body move, and make blood cells. Bone tissue is alive and constantly changes throughout our lives, to ensure it remains as healthy as possible. Every day, older, worn-out bone tissue is broken down by specialist cells called osteoclasts and rebuilt by cells called osteoblasts. This process of renewal is known as ‘bone remodelling’, or ‘bone turnover’. As we grow, osteoblasts work faster. This allows the skeleton to increase in size, density, and strength. During this period of rapid bone growth, it takes the skeleton just two years to completely renew itself. In adults, this same process takes seven to ten years. Bones stop growing in length between the ages of sixteen and eighteen. But the total amount of bone tissue you have— your bone density —continues to increase slowly, until your late twenties. Up until about the age of thirty-five, there is usually a balance between the amount of bone that is removed, and the amount of bone that is laid down. The total amount of bone tissue stays the same. From our late thirties onward, however, the amount of bone that is removed and the amount of bone that is laid down starts to get slightly out of balance. This happens at different rates in different people. More bone tissue is removed, and the total amount of bone tissue starts to decrease. During this process, your bones don't look any different from the outside. But inside, the outside shell of the bone thins. And the struts that make up the structure inside your bones become thinner and sometimes break down. The older you get, the more bone tissue you lose. This is why osteoporosis and broken bones become more likely with age. Your genes can determine the potential size and strength of your skeleton. Research shows that if one of your parents broke their hip, you are more likely to break a bone yourself. And if you've broken bones easily in the past, you are much more likely to break a bone in the future. Research also shows that after one broken bone you are two to three times more likely to have another in the future. Your gender is also relevant. Osteoporosis and broken bones are more common in women than men; over the age of fifty, half of women, but only one in five men will break a bone because of osteoporosis. There are several reasons for this. Having bigger bones reduces the risk of them breaking, and women tend to have smaller bones than men. Bones lose strength at a faster rate after the menopause because levels of oestrogen— the female sex hormone that helps keep bones strong —decrease. But women also tend to live longer, on average, so are more likely to live with the lower bone strength that comes with age. 12
