Dem bones, dem bones

Dr Cathy Agnew Donald highlights peak bone mass, when it starts to decrease and how to then maximise bone health.

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American country singer, Maren Morris, in her Grammy-nominated song The Bones, shares the following insight: “The house don’t fall when the bones are good.” And while her explanation of the lyrics is a commentary on sturdy relationships which can’t be shaken, I ask your indulgence to take these lyrics slightly out of context. The metaphor for me is of the house, which represents the human body, and it’s definitely less likely to fall when the bones are good.

From the moment life begins, our bone mass is growing, steeply at first and under the influence of calcium, vitamin D and hormones, until we reach our peak bone mass in the third decade of life. Some factors, such as gender (males achieve higher bone mass than females), race (black females achieve a higher bone mass than white females) and individual family susceptibility are determined genetically. But there are lifestyle and behavioural measures which can also help our attainment of maximal bone health. 

Maximise your bone health

• Attention to diet is important, especially regarding foods rich in calcium: dairy products, almonds and leafy vegetables (broccoli and kale). Recommended adult intake of dietary calcium per day is 1000mg (2 cups of milk contain 600g of calcium). This becomes especially important in children who are malnourished, who have eating disorders, such as anorexia nervosa, or who are vegans. Supplementation may be crucial in these circumstances. 
• Physical exercise should be a part of a daily routine.
• It’s well-known that smoking, alcohol and recreational drug use (notably meth and cocaine) lead to a decrease in peak bone mass in young users.

Peak and descending bone mass

When we reach our peak mass, both males and females descend slowly. However, the dramatic contribution of oestrogen, the main female sex hormone, is seen during the late fifth and the sixth decades. It’s deficiency and subsequent near-absence in post-menopausal women causes a dramatic fall-off in bone mass. 

Other factors of course play their part and relative inactivity, incorrect eating patterns and lifestyle and behavioural factors are an additional insult to already compromised bone. The importance of recognising osteopenia (bone loss) and osteoporosis (bones become weak and brittle) in this stage of life can’t be overemphasised.

Where osteopenia is a condition where people’s bone density is lower than usual for their age, osteoporosis is a far more severe incidence of bone loss that makes the bones weaker and more likely to fracture.

Testing for risk of fractures

Both conditions can be diagnosed by doing a DXA scan, a simple non-invasive investigation which is able to determine bone density relative to a given population. The FRAX criteria use the scan and relevant history from the patient to determine the risk of fracturefor a patient with osteopenia.

• Calcium often needs to be increased, with diet and sometimes supplements.
• Vitamin D levels need to be checked and supplementation given if necessary.
• The importance of physical exercise must be stressed.
• The patient must be assessed for suitability to receive hormonal therapy to increase oestrogen thereby controlling the balance between bone-forming osteoblast cells in the bone and bone-resorbing osteoclasts. Oestrogen also improves absorption of calcium in the intestines.
• In patients with osteoporosis all the above measures are important but there are also additional medications which can address the imbalance between bone formation and bone breakdown, thereby promoting bone growth. Agents such as bisphosphonates, denosumab and teriparatide are all used in current pharmaceutical interventions.

Cancer patients

Patients who have cancer have additional reasons for bone loss: 

• Chemotherapy, corticosteroid therapy and hormonal therapy can all affect bone mass. Bisphosphonates may be necessary to prevent osteoporosis and lifestyle modification, as discussed previously, is essential for a good outcome.
• Relative inactivity due to incapacitating illness reinforces the problem.
• Weight loss, which occurs when the presence of the tumour puts the body in a catabolic state, also adds to deficiency of essential nutrients.
• Specific cancers, for example, breast, prostate and ovarian, may require hormonal treatment which will block the good effects of the body’s bone-forming hormones.

So, while sometimes the genetic die is cast when it comes to our skeletal structure, it’s possible and extremely probable that lifestyle choices will be able to modify outcomes to keep our bones good and our houses from falling.

Header image by Adocbe Stock