Choline is an essential nutrient but not, strictly
speaking, a vitamin although it is often mistakenly thought
of as a member of the B complex, with which it has numerous
functions in common. Choline should be found in abundance
in a normally healthy diet, but deficiencies have been
linked with cardiovascular and liver disease, as well as
impaired cognitive function.
Until as recently as 1998 it was believed that the body
could manufacture an adequate supply of choline from the
closely associated nutrients, vitamin B12 and folic acid.
It is now accepted, however, that although the body can
indeed synthesise choline in limited quantities, an
adequate supply from the daily diet is also required for
the avoidance of a number of potentially serious deficiency
conditions and diseases.
Most choline in the body is contained in the phospholipids,
a particular type of fat molecule of which the most common,
phosphatidylcholine, more commonly known as lecithin, is
also an important dietary source of choline. Choline is
known to be crucial for the proper functioning of the
brain's neurotransmitters, and in the form of lecithin is
an important element in the composition of cell membranes
and effective biochemical communication between cells.
Lecithin, moreover, is vital for the liver's ability to
break down fat and cholesterol into the "Very Low Density
Lipoproteins" (VLDLs) which are carried around the body in
the bloodstream. Any deficiency of choline or lecithin may
therefore result in the liver becoming unable to metabolise
dietary fat and cholesterol in this way, and the resulting
accumulation may lead to the condition known as "fatty
liver" and ultimately perhaps to serious liver disease.
Some research even suggests that the changes in the liver
brought about by choline deficiency may lead to an
increased risk of liver cancer, although not all
authorities regard this research as conclusive.
VLDLs are also necessary for the production of the High
Density Lipoproteins (HDLs), the so-called "good
cholesterol", which is generally recognised as a
significant protector against cardiovascular disease.
There is also some evidence, although the research is not
yet universally accepted, that choline may assist in the
breaking down of homocysteine, a naturally occurring
protein within the body, which is strongly associated with
an increased risk of cardiovascular disease.
These protective effects may appear somewhat paradoxical,
because the milk, eggs and liver which are the richest food
sources of choline have been condemned in the past for the
amounts of supposedly dangerous cholesterol they introduce
to the body. A small (3oz) serving of beef liver, for
example, will provide more than 350 mg of choline, and a
single large egg perhaps 125 mg or more. So strict
vegetarians who adopt a low fat, and supposedly low
cholesterol diet which excludes these choline rich foods,
may paradoxically be placing their cardiovascular health at
risk.
Fortunately, however, this is a relatively simple problem
to resolve, as supplies of lecithin manufactured from soy
beans are readily available from health food stores. A
single teaspoon (3.5g) of the granular supplement may
provide around 130 mg of choline and is reasonably
palatable when sprinkled in suitable drinks or on cereals.
Peanuts and wheatgerm are also useful vegetarian sources.
To put the quantities mentioned above in some kind of
context: the US Food and Nutrition Board (FNB) has
recommended an "Adequate Intake" amount for choline of 550
mg a day, or a mere 4-5 teaspoons of granular lecithin and
it has been estimated that most adults are able to obtain
between 700 and 1,000 mg a day from a normally healthy
diet. Caution should be exercised, however, in the
treatment of the FNB recommendation which appears to have
been set at the lowest level necessary to avoid liver
damage. And it may be noted also that the 700 mg figure
for the lower end of the range of normal intake seems
perilously close to the 550 mg a day regarded as adequate
by the FNB.
But the avoidance of serious damage to a vital organ is, to
put it mildly, the very minimum one would reasonably expect
of a "healthy" diet, and a very long way indeed from the
optimum health which nutritional practitioners insist
should be the aim.
For example, although conventional medicine remains
reluctant to accept the link as proven, there is some
evidence that choline in amounts of up to 1g can improve
cognitive function and particularly memory. Choline is
known to act as a stimulant to the production of essential
neurotransmitting chemicals, and there is also some
evidence that high intakes during pregnancy may encourage
optimal development of the foetal brain and nervous system.
Although the possible reasons are not fully understood,
there is also good evidence that high doses of choline may
significantly improve athletic performance in long distance
endurance events such as marathon or triathlon.
So given that the FNB has established 3.5 grams (ie 3,500
mg) a day as the upper safe limit for choline intake before
any potential (and minor) side-effects might be
encountered, and that choline cannot be stored in the body,
there seems no reason not to aim for an intake well in
excess of the recommended minimum or "adequate" amount.
Granular soy lecithin can provide a simple and convenient
means of supplementation with such doses.
----------------------------------------------------
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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