Firstly, let's talk about bones and their role within the body. Bones have multiple functions including: support, structure, muscle attachment, blood cell production, protection for our vital organs and acting as a reservoir for minerals (including calcium and phosphorus). Bones are not a static organ but instead are a highly metabolic body tissue. Approximately 20% of your bones are remodelling (being absorbed and rebuilt) at any given moment in time, throughout your entire life.
The body is constantly adapting in order to maintain physiological balance via homeostasis. People are often aware that calcium is an essential mineral for strong bones, however, calcium is required for multiple purposes including the initiation of muscle contraction, nerve function, blood pressure regulation and multiple organ functions. The body has receptors to detect when blood concentrations of calcium are low, sequentially prompting the secretion of parathyroid hormone which in turn signals for calcium to be released from the bone by resorption.
A number of factors can impact the bone remodelling process, consequently increasing the risk of developing low bone density. Low bone density can be categorised into osteopenia (lower than average bone density) and this can develop into osteoporosis (more than 2.5 standard deviations below the average for that age and sex). Low bone density can increase a person's risk of experiencing a fracture, hence why it is important to try to build and maintain a healthy bone density.
Factors which increase a person's risk of developing low bone density:
Lifestyle causes:
Smoking
A lack of vitamin D
A lack of vitamin K
Sedentary behaviour
Alcohol and carbonated (fizzy) drink
A lack of dietary calcium
Low body weight (<55kg)
A diet that is too high in protein
Other causes:
Eating disorders (anorexia/ bulimia), celiac and bowel diseases, hyperthyroidism, certain medications (e.g. steroids and chemotherapy), postmenopausal, oestrogen deficiency, testosterone deficiency, genetic predisposition.
Ways to improve the chance of building and maintaining a healthy bone density:
Quit smoking! Tobacco has been linked with low bone density.
Reduce your alcohol consumption. Alcohol can cause vitamin D deficiency, which in turn leads to a reduction in the uptake of calcium. It can also increase the production of parathyroid hormone, which promotes calcium to be released from bones.
Move more! Osteoporosis was once thought to be a condition of the elderly, but studies have shown that people of any age with a sedentary lifestyle have lower bone density than their active counterparts. Weight bearing activities such as weight training and running are good as they place a load onto the body beyond that of the norm, hence encouraging the body to adapt. But any movement is better than not moving. On the other hand, even very active people are also at risk of having low bone density if they have a low body weight.
Vitamin D. This vitamin is essential for the absorption of calcium within the intestines. Vitamin D can be synthesised by the body, so make sure that you get outside each day for at least 20 minutes (although here in Canada, the sun is not strong enough between the months of October-March). Therefore, it is important to have foods high in vitamin D (some foods are fortified). If you are deficient in the vitamin, you may benefit from a supplement (please see your GP first).
Vitamin K. This vitamin does not get the acknowledgement it deserves! It is fundamental for the production of the proteins making up the structure of bone. It is found in green leafy vegetables such as: spinach, kale and broccoli. So don't forget to eat your greens!
Calcium. Eat foods that contain calcium. Calcium is a water soluble mineral, which can be found in: green leafy vegetables, fruit (e.g. oranges), legumes, nuts and seeds.
If you have an eating disorder, low body weight, hormone imbalance, bowel disease or are taking medication which may affect your bone density, book an appointment to discuss with your GP about preventative strategies to suit your body and lifestyle.
If you are living with osteoporosis, it is important that the risks for falls is kept to a minimum. Simple strategies such as taking away trip hazards from your home, not walking in icy conditions and working on improving your balance will all help.