Health and Fitness

During your thirties one per cent of your bone mass will be lost annually. This article looks at ways of preventing osteoporosis.

Bone is an essential part of our physical structure, yet it is one of the least understood components. And while scientists try to crack the puzzle of what affects bone, strengthens it and why it sometimes crumbles, millions women continue to suffer from osteoporosis, or brittle bone disease as it is called.

Sadly, osteoporosis is not just a problem in old ladies. The process that leads to osteoporosis begins in men and women in their thirties and can affect super-athletes, cancer, liver and kidney disease patients, diabetics, paraplegics, anyone with scurvy or anorexia nervosa, people receiving steroid treatment and anyone who is bedridden for a length of time.

It is the commonest of all disorders, affecting about one in five Asian and Anglo-Saxon women and adds millions every year to the health bill.

More than ninety-six percent of the body’s calcium is in bones and when there is not enough calcium in the bloodstream because of diet or hormone imbalance, it is drawn out of the bones, making them weaker and more brittle.

Put a piece of bone under a microscope and you will find a network of protein fibres with deposits of mineral salts, mostly calcium, dotted among them. If the salts are dissolved, the bone loses its hardness and if the fibres are destroyed it becomes brittle.

Causes of Osteoporosis

Add tobacco, caffeine and certain drugs to your diet and you deplete the salts, gradually weakening the bone. When the hormone oestrogen is removed due to menopause or a hysterectomy, the weakening occurs five times faster.

Understanding of bones has come a long way in the last five to ten years but the mystery of osteoporosis is still only partly solved. Doctors can tell us to drink milk, eat cheese and take plenty of exercise because they all strengthen the bones. They know the risks are higher among post-menopausal women, Asians and Anglo Saxons, thin people, heavy smokers and drinkers, and people who do little exercise.

Research suggests that caffeine doubles the body’s need for calcium and salt reduces calcium absorption. People with over-active thyroid glands are at greater risk and taking supplements of calcium, flouride and certain hormones can help prevent bone weakening. But what doctors cannot tell us is how alcohol affects bones (alcoholics are at ten times the risk) or what role vitamin D, tobacco or body fat play. Or why small-bodies, fair-skinned women are most at risk.

Men and women in their thirties start to lose about one percent of bone mass each year, but after menopause it shoots up to five percent. In men the incidence is far less. The key to this dramatic change is the oestrogen hormone, which is essential for bone formation as it prevents calcium being reabsorbed into the bloodstream.

Oestrogen production ceases with menopause and osteoporosis sets in about ten years later, putting women over fifty-five in the high risk group. But production also stops when the body is subject to extreme physical demand, as with anorexia nervosa sufferers and women who are super-athletes. In extreme cases these women cease menstruating as a defence mechanism because the body cannot support a pregnancy and because oestrogen is no longer produced. This can result in substantial loss of bone.

Bone formation starts again with the resumption of menstruation but the damage has already been done so many women start menopause with less bone density. There is therefore a greater risk of fractures early in post- menopausal life for these women.

Problems associated with Osteoporosis

The most common fractures affect the hips, wrists and spine. Osteoporosis can also bring about a loss in height because it causes the spine to shrink and curve, resulting in a stooped, hunched body which is not uncommon in elderly women.

The wrist fracture rate begins at about forty, increases with advancing age, then flattens out. The hip fracture rate begins a little later and continues in a steady upward climb. The difference is that as people get older, their reflexes are not as good and instead of putting out a hand to break a fall which could result in a broken wrist, they fall on their hip and fracture that instead.

Preventing Osteoporosis

So how do we prevent all this happening in the first place? There is no simple treatment for reversing osteoporosis so the emphasis is on prevention; and the earlier the better. A good calcium intake during the years of bone, development is the best solution.

Recommended daily allowances vary but it is generally accepted that children up to the age of seven should have about 800 milligrams while girls from twelve to fifteen need about 1,000 milligrams, as do women over fifty-five. The rest fall in the 800 to 1,000 milligrams range, except for pregnant and breastfeeding women, who require up to 1,300 and 1,400 milligrams.

Some experts suggest three 250-millilitre glasses of skim or low-fat, high-protein milk a day. Others point to cheese, fish, nuts (especially almonds) and green vegetables (spinach, broccoli and Chinese cabbage).

Oestrogen supplements after menopause greatly reduce the number and severity of fractures. But doctors say these should only be used by menopausic women before forty and women with low bone density or established osteoporosis.

Initially there was a scare that oestrogen treatment increased the risk of cancer of the uterus and thromboembolism (when fragments of blood clot form in the arteries), but doctors now say that this can be counteracted if the Oestrogen is taken with progesterone, a steroid found in the contraceptive pill. And progesterone in itself helps prevent calcium loss.

Calcium tablets are the most common form of prevention and they not only give extra calcium but also suppress the release of hormones from the parathyroid (the small gland next to the thyroid) which are known to increase bone re absorption. It has also been proved that fluoride, taken with calcium and vitamin D, increases bone density. Various combinations of growth hormone and phosphate are also effective in this.

Diagnosing Osteoporosis

But how do you know if you have osteoporosis? Until recently there was no way of telling until it was well advanced or you had a fracture to prove it. X-rays could only pick it up when thirty to forty percent of the bone had disappeared but now dual photon scanners can detect a two percent loss in the spine, hip or forearm. And hot off the drawing board an even more sophisticated technique: neutron activation analysis, which measures total body calcium.

Osteoporosis, as a bone disease, is still under-researched and until someone comes up with the definitive answer, we just have to increase our calcium levels up. Lots of milk, cheese and exercise will help, along with no cigarettes, alcohol or coffee.

Post-menopausic women need to drink a third of a glass of milk for every two cups of coffee to replace calcium the caffeine destroys. And make sure you don’t forget the other glasses in your daily allowance.