Potential link found between maternal diet just prior to conception and risk for leukemia in children
Women who eat a higher proportion of vegetables,
fruit, and protein prior to conception may lower the risk for childhood
leukemia in their offspring, according to an article in the August
issue of Cancer Causes and Control.
"This is the first time researchers have conducted a systematic
survey of a woman's diet and linked it to the risk of childhood
leukemia," said Dr. Kenneth Olden of the National Institutes
of Health, which funded the study. Leukemia is the most common childhood
cancer in American children.
Researchers compared 138 women who each had a child diagnosed with
acute lymphoblastic leukemia with a control group of 138 women whose
children did not have cancer. The children of all the women in the
study were matched by sex, age, race, and place of residence at
birth.
After comparing the women's diets in the 12 months prior to pregnancy,
researchers found that the higher the intake of vegetables, fruit
and foods in the protein group, the lower the risk of having a child
with leukemia.
One of the more surprising results of the study is the emergence
of protein sources, such as beef and beans, as a beneficial food
group in lowering childhood leukemia risk. "The health benefits
of fruits and vegetables have been known for a long time,"
said principal investigator Gladys Block. "What we found in
this study is that the protein foods group is also very important."
The researchers looked further and found that glutathione was the
nutrient in the protein group with a strong link to lower cancer
risk. Glutathione is an antioxidant found in both meat and legumes,
and it plays a role in the synthesis and repair of DNA, as well
as the detoxification of certain harmful compounds.
Within the fruit and vegetable food groups, certain foods -- including
carrots, string beans and cantaloupe -- stood out as having stronger
links to lower childhood leukemia risk. The researchers point to
the benefits of nutrients, such as carotenoids, in those foods as
potential protective factors. National guidelines recommend that
people eat at least five servings of fruits and vegetables every
day, and two to three servings of foods from the protein group.
"Fetal exposure to nutritional factors has a lot to do with
what mom eats," said Christopher Jensen, a nutritional epidemiologist
and lead author of the paper. "These findings show how vital
it is that women hoping to get pregnant, as well as expectant moms,
understand that critical nutrients in vegetables, fruit and foods
containing protein, such as meat, fish, beans and nuts, may protect
the health of their unborn children."
The few studies that have been conducted on maternal diet and childhood
cancer risk looked only at specific foods or supplements, and results
have been mixed. This study is the first attempt to capture a woman's
overall dietary pattern -- using a 76-food-item questionnaire --
and its relationship to the development of leukemia in a child.
Researchers also studied the use of vitamin supplements, but did
not find a statistically significant link to childhood leukemia
risk.
A growing number of scientists believe that genetic changes linked
to cancer later in life begin in utero. "It goes back to the
old saying to expectant mothers, 'You're eating for two,'"
said co-author Patricia Buffler. "We're starting to see the
importance of the prenatal environment, since the events that may
lead to leukemia are possibly initiated in utero. Leukemia is a
very complex disease with multiple risk factors. What these findings
show is that the nutritional environment in utero could be one of
those factors."
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