Osteoporosis drugs; not as straightforward as once thought

Osteoporosis - Vitamin D and Magnesium

Bisphosphonate drugs, commonly used to maintain bone density in osteoporosis patients, have recently become the subject of controversy. While they help maintain density of most bones, various studies show an increase in atypical femur fractures associated with their long term use.

Healthy bones are maintained through the break down of old bone cells which are then replaced with new healthy cells. Specialized cells called osteoclasts break the older bone down while their counterpart osteoblasts, build up the bone again with new healthy tissue. Bisphosphonate drugs absorb into the osteoclast cells, inhibiting their function which is the initial break down of cells. The result? Slower overall bone density loss.

Bisphosphonates decrease bone fractures of most bone types by 40% (and vertebrae fractures by over 50%). Prolonged use of these drugs (around 3 years plus) can cause an elevated risk in atypical fractures of the femur, studies show (1). The fracture begins with pain and unlike many other fractures, they don't need to be triggered by trauma or force (such as a fall). A recent study from the imperial college London found that the hip bones of those being treated with bisphosphonates had many micro-cracks and less mechanical strength (2).

Studies like these are gaining traction, making the future of bisphosphonate use unclear. With this in mind, what can be done to bring our bone density into our own hands?

Lifestyle and diet choices-Protecting your bone density

The best treatment is prevention, and this is especially applicable for osteoporosis. In our childhood/early adulthood, we build up bone density and this begins to decline from our mid 30s onwards. While it affects males and females, it's worth noting that women are especially susceptible to osteoporosis due to menopause (a decline in oestrogen production). Oestrogen has a calcium sparing effect, so when it declines during this natural process, bone density falls with it.

Being active can go a long way to maintain bone density, especially if weight-baring exercise is included (such as running or light weight lifting). According to the British Dietetic Association, both smoking and excessive alcohol consumption can increase the risk of osteoporosis as well (3).

A nutritionally dense diet containing adequate protein, zinc, calcium, magnesium and vitamin D and K can help ensure optimum bone density. Most of us obtain adequate calcium levels however, whereas both magnesium and vitamin D are common dietary insufficiencies.

Key for bone density; Vitamin D and Magnesium

Vitamin D is necessary for the body to absorb calcium. Dietary vitamin D intakes (from sources like butter, eggs and fish) are typically inadequate, though ideally we would synthesize enough when our skin is exposed to UVB rays from sunlight. The issue is, many factors limit our exposure to sunlight including;

  • Age (our ability to synthesize vitamin D from sun declines).
  • Season and latitude – less sunlight in winter and in northern parts of the world
  • Ethnicity/ Skin pigmentation- darker skin requires more sunlight
  • Personal habits: regularly use of sunscreen or covering up

Presently, the UK government recommends that everyone should consider taking a vitamin D supplement, especially in winter months when sunlight is lowest. Due to being a fat soluble vitamin, vitamin D oil capsules absorb in the gut better than the common solid tablet form. Available in two chemical forms, the D3 form (cholecalciferol) is generally considered less toxic, better tolerated and more stable than D2 (ergocalciferol).

Magnesium is a key mineral used for over 300 enzyme functions in the body. It has several approved health claims in the EU including its contribution to the maintenance of normal bones. Most magnesium supplements are single sourced, which may not be well absorbed in the gut (a common example is magnesium oxide). A multi-sourced magnesium supplement is ideal as it will offer a balance of high magnesium content and good bioavailability.

Healthy bone habits

Osteoporosis treatments are more complex than once though, though there's healthy behaviours we can adopt to help maintain bone density as much as possible. Smoking cessation, appropriate alcohol consumption, keeping active (with weight baring exercise) and a healthy diet with key supplements are behaviours we could all learn to adopt for better bone health.

References
1. Strotman P, Lack W, Bernstein M, Stover M, Summers H. Evaluation of common fractures of the hip in the elderly. Current Geriatrics Reports. 2016 Feb 5;5(1):38–43.
2. Wighton K. Drug used to treat weak bones associated with micro-cracks. 2017 Mar 1 [cited 2017 Mar 2]. Available from: http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_28-2-2017-13-6-7
3. [cited 2017 Mar 2]. Available from: https://www.bda.uk.com/foodfacts/osteoporosis.pdf

March 2017