Young female dancers can do much to prevent or minimise a common condition called 'osteoporosis' by eating plenty of calcium while they are growing. The mineral calcium feeds bone, so lack of calcium will result in fragile bones that are more likely to fracture. Calcium also has a role to play in muscle contraction and nerve transmission. Adequate intake is vital for long-term healthy bones for everyone, but even more important for dancers and athletes.
Osteoporosis is a painful musculoskeletal condition where bones, through loss of mineral calcium, become brittle and fracture easily. Medical treatment of established osteoporosis is very difficult, and statistics tell us that one in three women over the age of 60 will suffer a fracture as the result of developing osteoporosis. These fractures are a major cause of long-term disability and loss of quality of life in older women.
As well as the long-term consequences of osteoporosis, there may be short-term health problems for a dancer with low oestrogen levels and poor calcium intake. She is more prone to develop stress fractures and these may heal slowly. Other injuries are more likely to happen, due to an overload being placed on an already stressed and vulnerable body.
Bones are living structures in the body and are continually adapting to changing circumstances. They will become stronger (i.e. absorb more calcium) only when three conditions are met:
- When there is enough calcium available to be absorbed into the bones. Dairy products such as milk, cheese, and yoghurt are the best and most easily absorbed sources of calcium. Low fat varieties of these foods have just as much calcium as full-cream products and some are calcium enriched. Canned fish with bones, such as salmon and sardines, also have good calcium levels. Smoking or a high intake of alcohol or caffeine (in coffee and cola drinks) will significantly decrease calcium absorption.
- Bone will only become stronger if it needs to. Stress in the form of muscle pull and weight-bearing activity stimulates bone development. Regular exercise such as dancing, walking, jogging and aerobics classes will create positive stress on the bones.
- The female sex hormone oestrogen is tessential for the absorption of calcium into bones. Low oestrogen levels have a detrimental effect on bone mineral content. A woman's menstrual cycle is also controlled by the amount of circulating stop altogether. This is a normal consequence of menopause when the ovaries no longer produce oestrogen, but it can happen in younger women when they place extreme physical demands on their bodies, are under intense psychological stress or have severe weight loss from excessive dieting.
Save your bone bank
It is useful to think of bones as being like a 'bank' into which calcium can be deposited or withdrawn. This is happening every day according to the stresses and demands being placed on them.
Bones reach their greatest strength, called Peak Bone Mass, by the age of 20, so it is during the adolescent and early adult years that women have the greatest potential to 'save' their 'bone bank'.
After about the age of 35 there is a slow loss of bone mineral content (in men as well as women), then during menopause, women's bones lose large amounts of calcium due to the decreasing oestrogen.
Risk factors
The development of osteoporosis in later life depends on many factors. Some of these you will have no control over, such as being female, being small boned, your genetic inheritance and being Caucasian or Asian.
As a young female dancer, be aware of your own potential risks. Since peak bone mass is determined by age 20 you should do everything you can when you are young to ensure your peak bone mass is as high as possible.
The type and level of training experienced by dancers certainly provides sufficient stress on the bones to stimulate the strengthening effect, but this will not happen without healthy levels of oestrogen and calcium.
Have your oestrogen levels tested and be diligent about eating plenty of calcium-rich foods. For females, the recommended daily intake is:
- 8–18yrs : 1000mg
- 19–50yrs : 800mg (more if you are pregnant or breast feeding)
- 50yrs+ : 1000mg
Be aware of the amount of positive stress you put on your bones. Oestrogen can be significantly depleted by extreme dieting and weight loss, or during periods of intense exercise or psychological stress. This may result in late onset of menstruation and/or irregular periods—and even lack of menstruation.
Current evidence suggests that bone mass lost when young cannot be entirely replaced, even when oestrogen levels return to normal.
Cigarette smoking and high levels of alcohol and caffeine consumption will decrease your body's ability to absorb calcium.
Remember that the best treatment of osteoporosis is prevention when you are young.
If you are concerned about your diet or what is happening with your menstrual cycle, consult a doctor with a special interest in this area and with an understanding of your physical and psychological requirements as a dancer.
Related reading
- Bone health for life
- Bone health and female dancers: physical and nutritional guidelines, IADMS
- Strength from within by Nicolette Braybrook
- Australian Dairy Coorporation
- Better Health
- Resistance training is essential to stop the progression of, or reverse, osteoporosis! Karen Carmichael
Acknowledgements
Valerie Sayce and the Arthritis Foundation of Victoria