Saturday, April 5, 2008

Diet, Sunlight and Osteoporosis

Diet, Sunlight and Osteoporosis
The term osteoporosis refers to the unfortunately very
common condition by which bones become de-mineralised and
reduced in strength. Also sometimes known as "brittle
bones", it is particularly common in the elderly population
and a well established contributory factor in the
fractures, especially following falls, which are a
tragically frequent occurrence during this time of life.

Although the symptoms and consequences of osteoporosis are
at their most readily apparent during old age, it is a
condition which may develop throughout life. But although
some of principal risk indicators for the development of
osteoporosis, such as the ageing process itself, cannot be
avoided, the good news is that a little attention to diet
and nutrition, particularly the intake of calcium and
vitamin D, will go a long way towards delaying or even
avoiding the onset of this dangerous condition altogether.
And because the bones' nutritional demands are their
greatest during their growth phase, this attention cannot
begin too early in life.

The human body stores and requires more calcium than any
other mineral, and most of this is in the bones. Not
surprisingly, then, an adequate intake of dietary calcium
is essential for bone health, and a deficiency one of the
principal risk factors for osteoporosis. But although
essential, a good intake of calcium is not enough on its
own. Dietary calcium is relatively easy to obtain through
milk, other dairy produce and green vegetables, but even
lavish supplies cannot be absorbed without sufficient
vitamin D, and as many as 80% of sufferers from fractures
attributed to osteoporosis have been found to be deficient
in this vitamin.

Unfortunately vitamin D is less easily obtainable through
commonly consumed foods but a potentially, though not
necessarily easily, modifiable "lifestyle choice" which may
have a dramatic effect on levels of vitamin D in the body
is the amount of sunlight to which the skin is exposed.
For years medical orthodoxy was inclined to rely on the
fact that vitamin D can be synthesised within the body on
exposure to sunlight as evidence for the relatively low
significance of dietary intake. And there may even have
been some force in this idea in those far away days when a
significant proportion of the population worked in outdoor
occupations and children were accustomed to outdoor play
rather than TV, computer and video games.

But nowadays most people not only work indoors but are
strongly advised to cover themselves liberally with
sunblock on the rare occasions when they do expose
themselves to any natural sunlight. For those of us living
more than about 37 degrees north or south of the Equator,
where sunlight is in any case in very short supply for six
months of the year, this combination of circumstance makes
it doubtful that we will be able to obtain a sufficient
supply of vitamin D from sunlight. And this concern is
even more marked for the elderly, as the body's ability to
synthesise vitamin D from sunlight reduces with advancing
years.

Moreover, it is unfortunately not particularly easy to
obtain a good supply of vitamin D from a conventional
Western diet; oily fish, liver, eggs and certain cereals
being the most reliable, if unpalatable, sources. And
contrary to popular belief, dairy produce in itself is not
an especially rich source unless specifically enriched with
the vitamin.

But even when vitamin D rich foods are regularly consumed,
there are still other risk factors for osteoporosis which
need to be considered when considering the adequacy of
vitamin D and calcium intakes. Smoking and the immoderate
consumption of alcohol are perhaps amongst the more readily
avoidable of these. Less obvious, but perhaps at least as
important, is the need for physical activity, and in
particular load bearing exercise or strength training.

Low secretions of the main sex hormones, testosterone in
men and oestrogen in women, are also important precursors
of osteoporosis. Declining levels of these hormones with
advancing age is one reason why older people are much more
prone to this condition, a problem which is particularly
marked for women, given the dramatic drop in oestrogen
levels which follows the menopause.

But perhaps most important is the fact that the typical
modern Western diet, with its heavy reliance on processed
foods, is known to result in a high intake of sodium,
which, as well as being a cause of high blood pressure,
also increases the urinary excretion of calcium and other
vital minerals with corresponding adverse consequences for
bone density. The simplest and best solution to this
problem, of course, is the consumption of a diet rich in
fresh fruit and vegetables, rather than highly processed
foods, which will in itself ensure a reduction in sodium
consumption and an increase in potassium and other
minerals, ensuring the maintenance of a healthy balance.

To ensure adequate good intakes of both vitamin D and
calcium, however, it appears in the light of all of the
above to be wise to take advantage of a comprehensive
multi-vitamin and multi-mineral supplement.


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Steve Smith is a freelance copywriter specialising in
direct marketing and with a particular interest in health
products.
Find out more at
http://www.sisyphuspublicationsonline.com/LiquidNutrition/Ca
lcium-VitaminD.htm

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