Zinc is one of the many trace minerals required by the
body, but the fact that it's required in relatively small
amounts should not be allowed to obscure its significance.
It's required by the body for the production of more than
200 essential enzymes, one of the most crucial of these
being superoxide dismutase, a vital anti-oxidant.
The particular importance of superoxide dismutase lies in
its role in mopping up the superoxide free radicals which
are released upon the metabolism of oxygen within cells,
literally with every breath we take. Superoxide free
radicals react with other by-products of energy production
to form hydroxyl, the most damaging free radical of all,
and to attack the mitochondria of the cells themselves.
Since it is the mitochondria which ultimately produce the
energy for all the body's vital reactions, mitochondrial
damage due to free radicals can only mean the production of
less and less energy and the gradual deterioration and
degeneration of the entire organism.
As well as being vital for the body's manufacture of
anti-oxidants, zinc also helps the immune system to
regulate the process by which defective or worn out cells
are killed off by the body before they have chance to
multiply themselves and perhaps ultimately become
cancerous. These functions alone would make it one of the
key micronutrients which are vital to the body's long-term
health.
But there's much more to zinc than this, because it's now
known to be necessary for the production of the white blood
cells which are one of the body's first lines of defence
against infection, and for the proper functioning of the
thymus gland which is heavily involved in the regulation of
the immune system. So zinc is crucial not just in staving
off long-term degeneration, but in fighting off acute
infections.
And this well documented value as an immune system booster
has given zinc great popularity as a cold and flu remedy,
although the effectiveness of the many lozenges sold for
this purpose once illness is established remains open to
question. But the importance of a healthy immune system in
preventing infection in the first place is not in doubt.
And it's here that an adequate supply of zinc is essential.
Although the typical requirement for zinc is only 15 mg a
day, it is surprisingly easy to fall below this. Indeed
some estimates suggest that typical dietary intakes may be
as low as 9 mg for women and 13 mg for men, and even this
may be poorly absorbed so some nutritionists recommend
aiming for an intake of around 25 mg to ensure an adequate
supply.
It also needs to be remembered that certain groups of
people with depressed immune systems, such as HIV
sufferers, diabetics and alcoholics may have an increased
requirement for zinc. But by far the largest such group is
comprised of the over 65s. And it should be realised that
the consequence of a zinc deficiency may be much more
serious for these older individuals, given that their
immune systems are likely in any case to be less effective
than those of healthy young adults.
So the conclusion appears to be straightforward: ensuring
that the diet is adequate in zinc is vital to the
efficiency of the immune system, and therefore to long-term
health and well being. But as always with the human body,
the full story isn't quite so simple. The body functions
holistically, and an excess of any one nutrient may well
lead to a deficiency in another. Taking in too much iron,
for example, may in itself lead to a deficiency in zinc.
But in the case of an excess of zinc (defined by the US
Food and Nutrition Board as more than 40 mg a day), the
associated deficiency is of copper.
Deficiency in copper is rarely severe enough to produce
clinical symptoms, but this should not obscure the
important functions of this trace mineral. As with zinc,
adequate supplies of copper are vital for the production of
anti-oxidant enzymes and energy within the body's cells.
Sub-clinical deficiencies have also been implicated in
cases of mild anaemia and depression of the immune system.
The best way to counter these risks is, of course, to
consume a diet rich in both zinc and copper. Red meat,
particularly beef, and shellfish are known as good animal
sources, whilst nuts and beans offer a useful source for
vegetarians. Whole grains are a useful additional plant
source of copper. Plant sources of zinc, however, are
less well absorbed by the body than those derived from
animal sources, and so this is a nutrient which may require
particular attention for those following a vegetarian diet.
But given the poverty of modern Western diets in both
vitamins and minerals, supplementation may in any case be
necessary to ensure the health of the immune system,
particularly, as discussed above, for the over 65s.
Various forms of specific zinc supplement are readily
available, but it is probably wiser to ensure that any
supplementation of zinc is taken in a properly balanced
multi-mineral formulation also containing an appropriate
amount of copper.
----------------------------------------------------
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/In
formation.htm
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