Chromium is one of the lesser known of the trace minerals
which are essential to human health, but there are two
types you need to know about.
Hexavalent chromium has wide applications for industry, but
is toxic to humans both on external skin contact and
through internal consumption. Trivalent chromium, however,
appears to be not only completely safe, but potentially
highly beneficial to health, and all mentions of chromium
in the remainder of this article will relate only to this
type.
Perhaps the most important function of chromium lies in its
interaction with other key nutrients, particularly niacin
(vitamin B3) and certain amino acids, to form what is known
as the "glucose tolerance factor" (GTF), which enhances the
action of insulin and consequent metabolism of glucose to
produce energy within the body. The correct metabolism of
glucose, of course, is also crucial in regulating blood
sugar levels; and a lack of insulin or a decrease in the
body's sensitivity to it may give rise to the increased
blood sugar levels characteristic of diabetes. Less well
known, perhaps, is that insulin is also important in the
metabolism of dietary protein and fat.
Although the mechanism by which chromium enhances insulin
action is not fully understood there is evidence that
supplements of up to 200 mcg a day may have some effect in
reducing the need for additional insulin in diabetics.
This evidence, however, is based on Chinese research which
orthodox medical opinion remains reluctant to accept as
necessarily applicable to Western diets and obesity
patterns; insisting that more research is needed. But
whilst from the strictly scientifc point of view this may
be true, it is worth noting that the benefits were observed
at relatively low and harmless levels of supplementation.
So, as ever, regard must be had to the likely balance of
risk and reward.
Moreover, but perhaps logically enough, it has also been
suggested that a deficiency of chromium may be a factor
pre-disposing an individual towards the development of type
2, ie late onset, or non-insulin dependent, diabetes.
There is also some evidence that similar deficiencies in
chromium may be implicated in increased levels of blood
cholesterol, although orthodox opinion maintains that this
does not necessarily imply that supplementation in
non-deficient individuals will serve to reduce these
levels.
Chromium's role in the metabolism of glucose, protein and
fat has led to a widespread belief that it may help not
only in the reduction of body fat but in the acquisition of
lean muscle mass. But sadly, although there is some
research to support this idea, there is at least as much
which showed no such benefits, and chromium supplements
should not therefore be marketed or regarded either as a
bodybuilding or diet product.
Owing to the supposed paucity of information on the action
of chromium within the body, neither the US nor European
authorities have currently proposed a Recommended Dietary
Allowance (RDA). But the US Food and Nutrition Board has
suggested an Adequate Intake (AI) level of 35 mcg daily for
men and 25 mcg for women. Slightly higher levels are
suggested for pregnant or breast-feeding women; slightly
lower for children, adolescents and the over fifties.
Chromium in foods is commonly found in small, in fact
minute, quantities. Moreover these amounts have been found
to vary considerably even within batches of the same food.
For these reasons it is difficult to give accurate
indications of the amounts which may be expected in
servings of common foodstuffs. As a generalisation,
however, it may be stated that lean meats such as beef and
turkey (especially when processed), fresh vegetables,
particularly, broccoli and green beans, are probably the
richest readily available sources.
Even these, however, will seldom provide more than around
10 mcg per serving at most, and often considerably less.
It's also important to note that the foods high in refined
sugars which are so common in the modern Western diet are
not only themselves low in chromium but also appear to
increase the excretion of chromium from the body.
Unsurprisingly, therefore, it is estimated that the average
adult daily intake of chromium may be as little as 20 - 40
mcg a day, of which only around 2% may be successfully
absorbed and utilised by the body, and that deficiencies of
the mineral are consequently quite common.
But if supplements of chromium are to be taken, regard must
be had as always to the holistic functioning of the body.
Chromium is absorbed best, for example, when taken in the
presence of adequate vitamin C; whereas an excessive intake
of calcium by contrast, will further restrict chromium
absorption. But taking too much chromium is likewise to be
avoided because any excess may restrict the body's
absorption of the essential minerals zinc and iron.
Happily, however, none of this need be as confusing as it
may sound. Supplementing with between 50 and 200 mcg of
chromium a day appears to be both safe and potentially
beneficial provided it is obtained as part of a
comprehensive multi-mineral supplement. But for best
results, as always, this multi-mineral should be taken in
conjunction with a quality multi-vitamin preparation.
----------------------------------------------------
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
No comments:
Post a Comment