Bone is a living tissue that is constantly being built, reabsorbed and rebuilt. It is a highly organised arrangement of collagen fibres surrounded
by calcium and phosphate crystals that, in time, make the bones in your body as hard as a rock.
Bones become stronger gradually until about the age of 27 to 35 years when peak bone mass is reached. After this, from about the age of 35-40, the
amount of new bone being formed is not sufficient to replace bone that is dissolved. In addition, the body's supply of calcium, the mineral so
important for strong bones and teeth, starts dwindling with age too.
Calcium is not only important for strong bones and teeth but also plays an important role in processes such as nerve function, muscle contraction,
blood clotting and glandular secretion. However, when the calcium levels in the blood drop, often as a result of bad eating habits, inactivity and
reduced exposure to the sun (vitamin D increases the absorption of calcium from sources other than your own bones), calcium is withdrawn from the
bones leaving them thinner and weaker and more susceptible to splinters and breaks. This condition called osteoporosis.
Although peak bone mass is determined by a number of factors including genetics, many medical experts agree that calcium-rich food (milk, cheese,
sardines, nuts, broccoli and green leafy vegetables); dietary supplements, hormone replacement therapy (oestrogen, the female hormone stimulates
the absorption of calcium from the digestive tract and promotes bone growth) and exercise may help prevent the progressive loss of calcium and the
resulting bone-thinning conditions such as osteoporosis, from forming.
Who is at risk of osteoporosis?
- Women with a family history of osteoporosis
- Women from a Caucasian (white) or Asian background
- Women who are underweight with a small frame or physique
- Young women with ovulation problems and low oestrogen production levels who may have stopped menstruating for a while for any reason other than pregnancy and lactation
- Young women who are blonde with a very fair skin and older women who went grey before the age of 40
- Women who have had an early menopause (before age 45)
- Pre-menopausal women who have had their ovaries removed
- Postmenopausal women
- Women leading sedentary (inactive) lifestyles, who have a high caffeine intake and smoke or drink heavily
- Women with daily diets high in protein and phosphates (found in meat and refined foods) and low in calcium
- Women who have been treated with cortico-steroid drugs over a long period or who suffer from certain diseases such as hyperthyroidism (overactive thyroid gland)
- Those with insufficient exposure to sunlight (may lead to a lack of vitamin D)
Where does that leave the older athlete?
Medical and sporting experts encourage women to be active and to take part in weight-bearing exercises and sporting activities with a view to building strong healthy bones and thwarting the onset ageing and of osteoporosis in the later years. Studies have also confirmed that bone gets stronger when exposed to load and that weight-bearing exercise such as walking, running, aerobics and basketball - any exercises or sporting activities that improve muscle mass and strength such as resistance-type training - help because there is a relationship between muscle mass and bone mass.
It therefore makes sense to build up healthy, strong bones while you still can - up to the age of approximately 35 - and keep what you have in prime condition for the latter years.
This will entail:
- Increasing the mount of calcium in your diet, especially during and after menopause when declining levels of oestrogen hasten the gradual decrease in bone mass (less calcium is absorbed) and forces the body to turn to its own bones for its calcium needs
- Considering oestrogen replacement therapy during and after the menopause. However, do remember that this constitutes long-term treatment (10–15 years) to get optimum value. Non-hormonal treatment is available for women who are unable to have replacement therapy
- Taking part in regular weight-bearing, bone-building exercise such as walking or running at keeping it up for as long as possible - it should become a life-long habit to have lasting benefits
- Avoiding tobacco smoke, limiting your caffeine intake (3 cups daily) and alcohol use
- Getting reasonable exposure (not more than 30-60 minutes per day and remember the sun screen) to the sun’s ultraviolet rays as this helps produce vitamin D, which plays an important role in bone formation
It’s a sensible idea to have a baseline X-ray densitometry test done at the age of 45, or if you fall in a high-risk group. Remember, prevention is always better than cure
Exercise: yes, no or maybe?
Weight-bearing exercise and an active lifestyle help to build strong, healthy bones and may prevent the onset of osteoporosis in the later years.
However, sometimes too much of a good thing is no good at all. A restrictive diet to maintain low body weight in the hope of improving performance (runners, ballet dancers and gymnasts) coupled with an intense exercise and training program can actually have the opposite effect. Not only can this kind of stress disrupt a woman’s reproductive hormone balance and menstrual cycle, it can also impact negatively on her bone health. Women who do not menstruate lose bone density at the same rate as women who have reached menopause.
There is no maybe about it: Eating a calcium-rich diet and following a sensible, exercise program without losing too much body mass when you are young will build strong healthy bones and help prevent osteoporosis - as will taking supplements, hormone replacement therapy or some other non-hormonal option and staying fit and active during and after menopause.