Low fat vegan diet may reduce incidence of breast cancer.
(A summary of a recent peer-reviewed study)
T. Colin Campbell
Although many people believe
breast cancer is a genetic disease,
genes are to blame in only a small
minority of cases; about 1 in 20
breast cancer cases can be explained
by genes.
10
The vast majority of
women whose mothers had breast
cancer, for example, need not worry
about a genetic syndrome where they
definitely get breast cancer.
10
Beyond genes, diet has been extensively studied. Breast cancer has been
connected with diet in human studies for almost 50 years. Populations
around the world have widely varying incidence of breast cancer, and
early studies highlighted the fact
that countries that consumed higher
fat diets had higher rates of breast
cancer.
11
The level of fat in the diets
of these early international studies reflected the amount of animal
food in the diet. The fat was merely
a dietary marker for animal product
consumption.
In addition, a long history of many
experimental animal studies have
shown that dietary fat can promote
tumor growth.
12
Further, it has been
found that genetically similar populations adopt the risk of cancer prevalent in the region in which they live.
Chinese and Japanese people who
live in the United States get breast
cancer at far higher rates than those
living in their native homeland.
13,14
Several biological mechanisms are
thought to be involved, most prominently involving estrogen. For more
than a decade, it has been noted that
higher lifetime exposures to estrogens may increase the risk of getting breast cancer.
15
Asian women,
for example, eating a lower fat diet,
have much lower levels of estrogen
when compared to Western women.
In addition, multiple studies have
shown that women eating a lower
fat diet have lower estrogen levels,
though it is likely that low-fat diets
don't affect hormone levels until
they are "very low" fat.
15
In rural
China, rates of breast cancer were
about one-fifth the level of what we
see in Western countries. Women in
rural China also were found to have
later onset of menarche and earlier
menopause, leaving them with fewer
high-estrogen reproductive years.
16
In summary, there is very strong evidence that a low-fat, plant-based diet
is likely to be protective of cancer,
possibly explaining the much lower
rates of this cancer in traditional
cultures.
Many very large recent studies
investigating the role of diet in breast
cancer have reached conclusions that
are equivocal at best, suggesting very
little relation between diet and breast
cancer.
