Fat Linked to Breast Cancer
Fats that are common in some diets have been linked to an
increased risk of developing breast cancer.
The substances, called trans fatty acids, are prominent
in many processed and fast foods, margarines and some
vegetable oils. A study of nearly 700 postmenopausal
European women found that those whose bodies contained
the highest levels of trans fatty acids were 40 percent
more likely than those with the lowest levels to develop
breast cancer.
The greatest risk -- three and a half times as high as
the risk among those with the lowest levels -- was seen
among women with both the highest trans fatty acid
levels and low levels of polyunsaturated fatty acids.
The lead researcher on the study, Lenore Kohlmeier,
professor of epidemiology and nutrition at the
University of North Carolina at Chapel Hill, said the
findings might be especially relevant to American women,
whose intake of trans fatty acids is about twice that of
European and Asian women.
The new study is believed to be more accurate
than most because it measured the fatty acid content of
the women's body fat rather than asking them about the
foods they ate. The researchers analyzed tiny fat
samples taken from the buttocks, which provide the
truest reflection of dietary intake of various kinds of
fats.
Trans fatty acids do not occur naturally in food. They
are formed when vegetable oils are partly hydrogenated
to form margarine and other solid vegetable cooking
fats. Trans fatty acids are also added to some liquid
vegetable oils to extend their shelf life, although this
fact is not stated on the label. Previous studies have
linked trans fatty acids to an increased risk of heart
disease.
Ms. Kohlmeier said that people can reduce their intake
and body burden of trans fatty acids by changing their
diets. She said that it would take about two years for a
reduced intake of these fats to be reflected as a lower
level in stored body fat.