The
Vitamin That Does Almost Everything
Featured
on Berkeley Wellness, April 2003
Folatealso
called folacin or, when used in supplements or fortified foods,
folic acidis one of the B vitamins. It is not as well
known as vitamin C, but it deserves to be just as famous. Abundant
in green vegetables, beans, some fruits, and wheat germ, folate
is essential to the healthy division of cells and thus to fertility
and healthy offspring. It is also an important factor in heart
health, and may play a role in the prevention of colon, cervical,
and possibly even breast cancer.
Folate
= healthy mothers and babies
One
folate success story started with the discovery that low blood
levels of this vitamin in pregnant women can lead to neural
tube birth defects, such an spina bifida and anencephaly (failure
of the spine and brain to form normally), which can be disabling
or fatal for the infant. These defects occur in the first days
or weeks of pregnancy, before a woman can know she is
pregnant. So women should start building folate stores at least
several weeks before becoming pregnant. Adequate folate levels
may also reduce the risk of early miscarriages. Another benefit:
Pregnant women who take folic acid supplements are less
likely to develop high blood pressure during pregnancy.
In
1992 the U.S. Public Health Service urged all women of childbearing
age to consume at least 400 micrograms of folate daily; and
in 1998 the government began to require food makers to fortify
refined grain products to help meet this goal. Since then the
number of neural tube defects in the U.S. has fallen by almost
25%, and about 4,000 children have been spared. And the picture
will certainly continue to improve. This is a worldwide effort,
not just an American one.
To
be sure theyre getting enough folate, all women of childbearing
age should take a multivitamin containing 400 micrograms of
folic acid or eat a highly fortified cereal (a few supply 400
micrograms), as well as foods rich in folate. The folic acid
from supplements and fortified foods is better absorbed than
the folate that occurs naturally in foods.
Folate
= healthy hearts?
Homocysteine
is an interesting chemical in the ongoing puzzle of heart disease.
Our bodies manufacture it, and high levels are now thought to
be a risk factor for heart disease. In the normal course of
things, three B vitamins (B6, B12, and folate) convert homocysteine
into amino acids. If you are deficient in these vitamins, especially
folate, homocysteine may build up and damage blood vessels,
starting the cascade of events that lead to a heart attack.
As weve reported (Wellness Letter, March 2001),
the homocysteine theory of heart disease is still only a theory;
but theres every reason to increase your consumption of
folate and other B vitamins. It might save your life.
Other news: Several small studies have shown that boosting
folate intake improves blood vessel function in people who already
have heart disease. And a large government study in 2002 found
that people who consume the most folate have a lower risk of
stroke and heart disease than those consuming little folate.
Folate
= protection against cancer?
Since
folate is so important in healthy cell division, it makes sense
that it might prevent the unhealthy cell divisions characteristic
of cancer. A high folate intake appears to play a role in reducing
the risk of colon cancer, according to a recent Dutch study
and other research. Diets rich in fruits and vegetables go along
with a lower risk of colon cancer, and the folate in these foods
may be one reason for this. Theres also some evidence
that folate may help prevent cervical cancer.
As
for breast cancer, the evidence for a protective effect is less
convincing, but some studies have suggested that a high intake
of folate may reduce the riskbut only in certain groups
of women, such as heavy drinkers.
Complicating
factors
Folate
has some enemies. One of these is alcohol. Heavy drinking lowers
your stores of B vitamins, especially folate. Thus, heavy drinking
and a poor diet may increase cancer risk synergisticallythat
is, more than either factor would alone.
Another
complicating factor for folate may be sunlight. A recent article
in Scientific American cited evidence that ultraviolet
radiation can actually penetrate the skin and destroy folate
in the bloodstream, especially in fair-skinned people. This
is another reason to avoid sunbathing.
Bottom
line: The adult RDA for folate is 400 micrograms daily
(600 micrograms for pregnant women). A diet rich in vegetables,
fruits, and grains should supply ample amounts. Particularly
good sources are leafy greens, broccoli, beans, wheat germ,
whole grains, peanuts, corn, oranges, and orange juice. A cup
of cooked spinach or asparagus has 260 milligrams, a cup of
beans anywhere from 160 to 350. And, as weve said, the
folic acid in supplements and fortified grain products is even
better absorbed. Most multivitamins have 400 micrograms; many
breakfast cereals are fortified with high levels of folic acid.
And
by the way: The government has set an upper limit for
folic acid from pills or fortified foods at 1,000 micrograms
a day, since higher levels can worsen the neurological damage
of a vitamin B12 deficiency. This is especially a problem in
older people. Such high levels can also "mask" a B12
deficiency and thus delay its diagnosis and treatment.
Reference Source 98