Weak bones can be caused by your lifestyle. The good news is that you can make them stronger - whatever your age. You can't blame your family history entirely for giving you weak bones. While our genes account for 60 per cent of our bone density, the remaining 40 per cent is influenced by our lifestyle. The good news is that while we reach our peak bone mass aged 25 to 30, there are plenty of changes we can make at any age to lower the risk of osteoporosis. Osteoporosis runs in families, but from our forties onwards our bones gradually lose their density as a part of ageing. Post-menopausal women are more at risk because of the drop in levels of oestrogen, which has a protective effect.

6 food rules for bone strength:

- Eat a calcium-rich diet; the current recommended daily dose is 700mg, but you should consume around 1,000mg. The best sources are dairy products, but other sources such as green leafy vegetables, baked beans, bony fish and dried fruit are good too.
- You need vitamin D in your diet to help calcium to be absorbed properly. It's produced by the body from sun exposure and is found in oily fish and butter.
- Consider a vitamin D and calcium supplement.
- An alkaline diet -one that's rich in both fruit and vegetables - will boost absorption of calcium and strengthen bones too.
- Make sure that 15 per cent of your daily calories come from protein.
- Eat 100mg of phytoestrogens a day - sources include linseeds, soya milk and tofu. They mimic oestrogen, helping to preserve bone density during and after the menopause.

Exercises for strong bones:

- Walking for 20 minutes, three times a week, has a protective effect on bones. It also improves muscle control and co-ordination.
- Try exercise such as jogging, tennis, squash and weight-training three times a week, for an hour or so. As a living tissue, bone responds to changes in force and different loads by growing stronger.
- Swimming, particularly backstroke, helps muscle function, which is also good for your strength, mobility, balance and posture.

Clean up your lifestyle:

- Smoking has a toxic effect on bones and may cause women to have an early menopause.
- Reduce salt and alcohol: high consumption can interrupt calcium absorption. And heavy drinking can accelerate the menopause, so stick within 14 to 21 units a week.

Take the right bone test - A DEXA - dual energy X-ray absorptiometry - bone density scan can diagnose osteoporosis or fragile bones, but the first symptom is often a painful fracture. There is a shortage of NHS scanners in the UK, so those at high risk of osteoporosis or patients who have experienced a fracture are prioritized. Talk to your GP about a referral. A bone marker test, which requires a sample of urine or blood, can help assess the rate at which bone broken down or formed and is available at specialist centers.

Are you at risk? - If one or more of the following apply, you can be at risk:
- Does osteoporosis run in your family? (eg. Has your mother ever suffered a hip fracture?)
- Have you had an early menopause (before age 45) or hysterectomy?
- Have you ever missed periods for six month or more as a result of over-exercising or over-dieting?
- Do you smoke?
- Do you drink heavily (more than 14 to 21 units a week ?)
- Do you rarely exercise?
- Do you diet regularly?
- Have you ever taken a long course of high-dose corticosteroids - to treat asthma, for example.

How is osteoporosis treated?
- Patients are usually prescribed a vitamin D and calcium supplement
- Non-hormonal drugs called bisphosphonates are prescribed to help maintain your bone strength and reduce fracture rates. SERM (selective estrogen receptor modulator) drugs, such as Raloxifene, act in similar ways to oestrogen in helping to strengthen bones. Anabolic agents are also used to help the patient develop new bone tissue.
- HRT is no longer used by most doctors as a treatment for osteoporosis as it's now thought that the potential risks from taking it outweight the benefits.

How to increase bone strength in your 20s, 30s, 40s, 50s:
+ Teens: Dont smoke! It leaches calcium from bones, particularly when you're young.
+ 20s : Build up bone credits with weight-bearing exercise and calcium- rich foods. If you're worried about fat, remember that skimmed milk has more calcium per 100ml than whole milk.
+30s : Pregnancy and breast-feeding uses up huge amounts of calcium, so if you're planning to have a baby, expecting a baby or nursing, aim for four servings of calcium-rich foods a day and see your GP about taking a pregnancy supplement.
+40s : The latest evidence is that some 40-somethings are deficient in vitamin D, which is vital for healthy bones. Aim to go outside for a brisk walk at lunchtime to catch some sunshine at least three times a week.
+50s : We're less able to absorb minerals as we get older, so now is the time to talk to your GP about supplements. And increase your intake of phytoestrogens.
+60s and beyond : Exercise is still very important and it's never too late to start. Even a brisk 20-minute walk, three times a week, will do the trick.