X-Message-Number: 24580
Date: Thu, 2 Sep 2004 05:19:31 -0700 (PDT)
From: Doug Skrecky <>
Subject: dietary modulation of DNA damage

Mutat Res. 2004 Jul 13;551(1-2):213-22.
The influence of dietary flaxseed and other grains, fruits and vegetables
on the frequency of spontaneous chromosomal damage in mice.
  Spontaneous genetic damage, whether mutations or chromosomal
aberrations, undoubtedly arise from a variety of sources including
replication errors, oxidative damage, background radiation, and chemical
exposure. Given the numerous correlations between diet and cancer, it
seemed possible that diet could influence the spontaneous rate of DNA
damage and its genetic consequences. Since diets high in vegetables,
fruits, and grains are associated with lower rates of cancer, we
supplemented the diets of mice and measured the frequency of micronuclei
in the peripheral blood. Micronuclei arise from broken chromosomes or
chromosome loss in the erythroblast. They are first seen in the short
reticulocyte stage of the red blood cell but persist for the entire
30-day lifespan of the cell in mice. C57Bl mice were placed on a defined
diet (AIN-93G) supplemented to 20% final dry weight with grains or
freeze-dried fruits or vegetables. The micronucleus frequency was
measured in a pre-exposure blood sample and every 2 weeks thereafter for
6 weeks. This was possible in spite of the low spontaneous frequency of
1/1000-2/1000 cells by the use of a novel flow cytometric method, which
permitted the analysis of both the mature red blood cells and
reticulocytes. Of the foods tested, flaxseed proved to be the most
protective by reducing the incidence of micronuclei in both the
reticulocyte and normochromatic erythrocyte cell populations by 30 and
11%, respectively. The results show that at least one class of spontaneous
genetic damage can be modified by diet and suggests that short-term
experiments with small numbers of animals can be used to identify dietary
anticarcinogens that may influence human cancer rates.

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