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Folic Acid
Can Be A Key Protector Against Heart Disease
The somewhat misleadingly
named folic acid is in fact one of the most important of the water soluble B
complex of vitamins. In the form of folates it is found naturally in the body as well as in
various common foods. As folic acid it
has been extensively researched and is widely available as a food
supplement.
Inadequate dietary
intake of folates by pregnant women has been widely publicised as a cause of serious and even fatal birth
defects. Research has also suggested a
strong association between folate deficiency and an
increased incidence of certain of the more common cancers.
The implications of these findings
will be covered in subsequent articles in this series, but this article will
focus on the role of folates and folic acid in
regulating blood homocysteine, excessively high
levels of which have been identified as a key risk factor for both
cardiovascular disease and Alzheimer’s disease.
Homocysteine is a protein formed as a
perfectly normal by-product of the body’s digestive processes and in
optimally healthy individuals it will be removed harmlessly from the body But its
effective removal is heavily dependent on the presence of adequate supplies of
three B complex vitamins, B6, B12 and folic acid or folates.
The build up of excess homocysteine if these vitamins are not present in
sufficient quantities can have severe consequences. A large 1997 European study of young and
middle aged adults showed a more than doubled risk of cardiovascular disease
and stroke for individuals whose blood homocysteine levels
were in the top fifth of the normal range.
In fact some sources attribute as many as 10% of heart attack fatalities
and an even higher proportion of stroke deaths directly to high homocysteine levels.
Since these are still two of the biggest causes of premature death and
disability in the affluent Western world, such figures are particularly
alarming.
The link between raised homocysteine levels and Alzheimer’s disease is not
quite so well established, at least in the view of orthodox medicine, but a
number of studies have found a clear association. It has also been observed that sufferers from
this appalling disease are more likely to be deficient in both folic acid and
dietary folates.
Not surprisingly perhaps, given that damage to blood vessels appears to
be one of the principal effects of elevated homocysteine,
it has also been strongly linked with vascular dementia.
The role of folic acid and folates in lowering blood homcysteine
levels is well established, with one recent study showing 60% and 90%
reductions when supplement regimes of 0.2 mg and 0.4 mg respectively were
followed. And given that high homocysteine levels have been shown to increase the risk of
cardiovascular disease,
as well as Alzheimer’s and other dementias, it might be thought self-evident that
supplementation should be a powerful weapon against them.
Conventional medicine, however,
continues to be cautious about recognising the
link. Although there is good evidence
from at least one ten year study that high levels of dietary folate can reduce heart attack risk by more than 50%, there
appears not be the same direct corroboration for the effects of folic acid
supplementation. Somewhat bizarrely,
therefore, the profession finds itself recommending supplementation for the
purpose of reducing the elevated homocysteine levels
known to increase the risk of disease, but declines to recommend it as a
specific protector against the disease itself.
Not surprisingly, nutritional therapists show no such hesitation, and
many recommend supplementation at levels far in excess of the officially
Recommended Dietary Allowance (RDA) of 400 mcg (0.4 mg) a day.
But whatever the benefits of high
dosage supplementation, it is clear in any case that a diet rich in folates can only be of benefit to the body’s general
health. This is because amongst the best
and most readily available sources of folates are
leafy green vegetables and orange juice which also provide a plentiful supply
of valuable anti-oxidants.
A single cup of spinach or
asparagus, for example, may provide as much as 130 or more micrograms (mcg) of folate; a small glass of orange juice perhaps 80 mcg. Pulses such as beans and lentils are also
good sources, the latter providing around 180 mcg in just half a cup, beans
between 80 and 140 mcg according to type.
Best of all, however, is fortified
breakfast cereal, a single cup of which may yield between 200 and 400 mcg,
reflecting the FDA’s insistence on the addition of folic acid to refined
grain foods, including bread.
Despite
this official recognition of the importance of this nutrient, the US Food and
Nutrition Board nevertheless recommends that folic
acid intake should be limited to 1,000 mcg (1 mg) per day. But this is not so much because of any
possible ill effects of the folic acid itself, but rather because it may cure megaloblastic (commonly known as pernicious) anaemia which
is one of the symptoms of an underlying deficiency of vitamin B12. If the removal of this symptom means that the
deficiency is consequently undetected and left untreated, the neurological
consequences may indeed be severe.
But
to the educated layman the solution to this potential problem appears readily
apparent. It is simply to ensure,
through supplementation if necessary, that a generous intake of vitamin B12 is
also obtained. This should present no
difficulty if the standard recommendation never to take one of the B vitamins
in isolation is followed. These vitamins
should always be taken as part of a supplement containing the entire complex,
and for maximum benefit should preferably be accompanied by a comprehensive
multi-mineral.
Steve Smith
