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A California study found that only one in three
residents of the state reported eating five or more servings of fruits and
vegetables a day -- the minimum recommended amount. This translates into
vitamin deficiencies which, in turn, mean altered DNA, Ames said. ``What
is becoming clear is that there is a tremendous amount of DNA damage in
people from not having their vitamins and minerals,'' said Ames, a
professor of biochemistry and director of the NIEHS center. ``People, when
they think of cancer, they think of chemicals in the water or pesticide
residue. I just think it's all a distraction.'' Many vitamins act as
antioxidants, preventing the damage, known as oxidation, that changes DNA
and allows cells to become cancerous. ``If you don't get your vitamins C
and E, it is like irradiating yourself,'' Ames said.
Folic acid, a B vitamin, may be particularly important.
Christine Skibola and Martyn Smith of Berkeley found one gene involved in
a person's susceptibility to leukemia helps process folate. ``Our results
suggest that folate metabolism may play a key role in the development of
acute lymphocytic leukemia (ALL),'' they wrote. Ames's team has shown in
past studies that cells from people deficient in folic acid contained
specific genetic mistakes. ''Now we have shown that B6 deficiency does the
same thing,'' Ames said.
Australian researchers told the conference they found
vitamin B12 deficiency can damage chromosomes, and other research
suggested that people deficient in zinc and iron may also suffer genetic
damage. ``You can solve all these problems with a multivitamin pill,''
Ames said. ``...It's very hard to get poor to change their diets and they
are just not doing it. I think you should tell them to eat five portions
of fruit and vegetables a day and take vitamins as insurance.''
The Institute of Medicine, which advises the nation on
such matters, says people should try to get their vitamins from food. Yet
the IoM recommended for the first time in 1997 and 1998 that people take
supplements -- of calcium, to prevent osteoporosis, and of folic acid,
shown to reduce the risk of birth defects. But earlier this year the
institute warned against taking too many supplements, saying high levels
of vitamin C can cause diarrhea, too much vitamin E may increase the risk
of stroke and excessive selenium can cause hair loss and brittle nails.
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