From our 40s onwards, our bones gradually lose their density as a natural part of ageing.
Osteoporosis is a condition that affects the bones, causing them to become weak and fragile and more likely to break (fracture). It has no symptoms so the first clue may be seen if you fracture a bone.
Whether you have osteoporosis or just want to build strong bones for the future, there are several things you can do to maintain your bones.
Eat calcium-rich foods
Calcium is important for maintaining strong bones. Women and men aged 19 and over (including pregnant and breastfeeding women) are recommended to have 1,000 mg of calcium a day while women over 50 and men over 70 are recommended to have 1,300 mg a day. Calcium is found in a number of different foods including dairy foods, green leafy vegetables, and tofu.
If you can't get the recommended amount of calcium from your diet you may need to take a calcium supplement, particularly if you have low bone density. Osteoporosis Australia recommends taking a maximum of 500-600 mg of calcium per day. Talk to your doctor about whether you need a calcium supplement and what the right dose is for you.
Get your sunshine quota
Your body needs vitamin D to help it absorb calcium. Vitamin D is found in oily fish, liver, fortified spreads and cereals, and egg yolks. Your body also makes its own vitamin D when you're exposed to sunshine.
Exercise like weight training, walking and running can help strengthen bones.
To produce enough vitamin D most Australians only need a few minutes a day of sunlight during summer and a couple of hours of sun exposure spread over the week while during winter. The amount of exposure to sunlight needed depends on your skin type (darker skin requires longer exposure), the time of year, which state you are in and your lifestyle. Visit the Cancer Council website for more information on Vitamin D and sun exposure requirements.
Go easy on the protein
Excessive amounts of meat, cheese and protein make body acid, which drains the body of calcium and weakens bones. Keep your diet balanced.
Your meals should contain protein (meat, fish, eggs, nuts, seeds), fresh fruit and vegetables, and carbohydrates (bread, pasta, potatoes and rice).
The more you smoke, the more likely you'll get osteoporosis. Aim to cut down or, better still, quit smoking altogether. A great place to start is to check out the Quit Now website and its variety of information and tools to support you in quitting smoking.
The Quit Now: My QuitBuddy is a personalised interactive app with quit tips, daily motivational messages and countdown to quitting reminders. The user records their goals in pictures, words or audio messages and the panic button when craving provides a range of distractions. Call the Quitline on 13 7848 or a buddy from the app, or post a note on the community board. The Quit Now: My QuitBuddy is free to download on iPhone, iPad and Android phones. To install visit iTunes online store or Google Play store.
Cut out the salt
Salt is thought to speed up the body's loss of calcium. So try to limit your daily salt intake to the recommended amount. Australian adults are recommended to consume less than 4g salt (equivalent to 1,600mg sodium) with 6g salt (equivalent to 2,300mg of sodium) the maximum daily upper limit. This upper limit is equivalent to about a teaspoon of salt.
Try not to add salt to your food, flavouring with herbs or a squeeze of lemon juice can be a good substitute.
Looking at nutrition labels can also help you reduce your salt intake. Look for foods with 120mg sodium or less per 100g. Crisps, ham, cheese, cooking sauces and processed foods such as pies, pizza and soups are all high in salt.
Bones get stronger when you use them. A great way to strengthen them is with weight bearing exercise. This includes walking, running, dancing, golf or tennis. It doesn't include cycling or swimming (although swimming is good for staying flexible).
Bones also benefit if you lift and carry things. Weight training is ideal, but carrying shopping, gardening and housework all count. If you are new to exercise it's a good idea to talk to your doctor before you take up any new exercise activity, to make sure it's right for you.
Alcohol, tea, coffee, cola and other soft drinks reduce the amount of calcium you absorb, and weaken bones. Stick to the recommended amounts of alcohol, and swap your caffeine-fuelled drinks for water.
Maintain a healthy weight
Losing too much weight too fast under a crash diet can increase your risk of osteoporosis. The same is true if you're anorexic (or, for women, if you're so thin that your periods have stopped).
Weight loss can cut the amount of oestrogen (a hormone that helps to protect your bones) in your body. If you need to lose weight, do it sensibly.
Sources: Australian dietary guidelines (Australian Dietary Guidelines - 2013), Medical Journal of Australia (MJA Open, Volume 2 - Supplement 1), NHS Choices, UK (Exercise and bone health), NHMRC - Nutrient reference values (Sodium), NPS MedicineWise (Balancing the benefits and risks of calcium supplements), Osteoporosis Australia (Clarifying the issues - Calcium, Vitamin D and Supplements)