Why does it matter?
- Our bones change as we age.
Bone is a living tissue and is always in a process of removing mature bone tissue and forming new bone tissue. Before maximum bone density is reached around our mid-20s to late 30s, this process is balanced in favour of bone growth and bone breakdown is much slower. This allows us to grow taller, stronger bones for support and structure throughout the lifespan. However, after we reach peak bone mass, the balance starts to shift and bone degradation begins to occur at a faster rate than bone formation.
It is an inevitable part of ageing. As our bones age and change, our focus should be on maintaining the bone we have. The most important reason to maintain our bone health is to protect against bone diseases such as osteoporosis and to prevent fractures.
Risk Factors for Osteoporosis
- Gender – Oestrogen is essential for bone retention, as women go through menopause and oestrogen declines, bone loss is accelerated. Therefore, women are at greater risk of osteoporosis than men, especially once they reach 54 years (see Figure 1).
- Age – The older you are the greater your risk. Once your peak bone mass is reached, turnover increases but bone is not replaced at the same rate as it is being lost, thus leading to a decline in bone mass.
- Race – Caucasian and Asian ethnicities are more likely to develop osteoporosis.
- Genetics – Family history may indicate low bone densities being an inherited trait. Genetics may also determine someone’s bone structure and body weight. Thin, petite women are at greater risk of poor bone health as they have less to lose in the first place.
- Sedentary Lifestyle – Sedentary behaviour increases likelihood of osteoporosis as exercise stimulates bone formation, calcium retention and responds well to physical activity that puts stress on the bone such as running or dancing.
- Stressful Lifestyle – A stressful lifestyle and/or inadequate sleep can exacerbate bone loss as the body releases a stress hormone (cortisol) which promotes further bone breakdown. Not getting enough sleep is a problem when the body does not have time to relax and return cortisol levels back to normal because if they stay elevated, bone loss will increase.
- Alcohol Intake – Drinking more than the recommended servings of alcohol (see Alcohol Recommendations)
Healthy Eating for Healthy Bones
A healthy diet can be achieved when eating a variety of foods from the five food groups. A varied diet as recommended in the Australian Guide to Healthy Eating, will provide the necessary foods to reduce risk of osteoporosis.
For more information on healthy eating and how to maintain a balanced diet visit Eat for Health
Bone Healthy Nutrients
Many nutrients contribute to build healthy, strong bones. These nutrients include calcium, vitamin D, phosphorous, magnesium, vitamin A, fluoride, vitamin K and protein. However, more of one vitamin does not substitute for less of another.
Calcium is probably the most well known mineral required for healthy bones as it is a major mineral that makes up our bone tissue. Once calcium is absorbed into the bloodstream it is carried into the bone cells and deposits calcium as necessary.
- Fish with edible bones, remember to eat the bones
- Dark leafy greens such as spinach or kale
Vitamin D directs the mineralisation of bones. Basically, it tells calcium what to do and where to go in the body. Without enough vitamin D, it is not possible to absorb enough calcium, regardless of the amount consumed. Adequate sun exposure can ensure adequate vitamin D levels which is necessary for calcium absorption. As we age, our skin’s ability to convert sunlight to vitamin D reduces so it is necessary to get more sunlight. Whilst our main source of Vitamin D is gained from sunlight absorbed through the skin, there are small amounts in some foods.
- Fortified foods such as dairy products, juices and cereals
- Egg yolks
- Oily fish such as salmon, herring and sardines
Phosphorous is a major mineral deposited in the bone structure to develop the bone’s density and overall strength.
- Dairy Products (milk, yoghurt and cheese)
Magnesium is another mineral that is deposited in the bone mineralisation process.
- Nuts – cashews, almonds and walnuts
- Seeds – pumpkin seeds, sunflower seeds and chia seeds
- Wholegrains – quinoa, bran cereal, wholemeal bread and brown rice
- Legumes – chickpeas
- Dark Chocolate/Cocoa
Vitamin A assists in making bone proteins that contribute to bone mineralisation.
Food Sources of Vitamin A
- Dairy Foods – Milk (fortified), butter, cream and cheese
Food Sources of Beta Carotene
- Orange fruits and vegetables – carrots, sweet potato, pumpkin, capsicum, tomato, mango, pawpaw, peaches and oranges.
- Green vegetables – spinach, broccoli, peas and green beans.
Fluoride plays a role in hardening the bone to stabilise it and maintain its strength and integrity.
- Fluoridated water
Vitamin K assists in making bone proteins that contribute to bone mineralisation.
- Dark leafy greens – kale, seaweed, Swiss chard, spinach and lettuce.
- Cruciferous vegetables – broccoli, cauliflower and cabbage.
Protein is a valuable nutrient for maintaining muscle mass and helping repair joints after injury. Muscle tissue helps to support the skeleton, maintain stability/balance and prevent falls.
- Animal foods – beef, pork, chicken, turkey, fish, eggs, yoghurt and milk.
- Legumes – chickpeas, lentils, red kidney beans, soy beans and baked beans.
- Nuts and seeds – almonds, cashews, walnuts, linseeds, pumpkin seeds and sunflower seeds.
For more information about bone health, head to Osteoporosis Australia
Kouris, A. (2011). Food sources of nutrients: A ready reckoner of macronutrients, micronutrients and phytonutrients.
Osteoporosis Australia. (2013). Risk factors for osteoporosis. Retrieved from http://www.osteoporosis.org.au/about/about-osteoporosis/risk-factors/