The risk of dying at any point in time increased by 40 percent for every 1,000 grams of fat the women consumed per month.

The risk of dying at any point in time increased by 40 percent for every 1,000 grams of fat the women
consumed per month.

There were some bright spots in the study. Risk of progesterone-negative
tumors fell by 30 percent. And those women who made the greatest reductions
in fat intake had a more significant drop in overall risk, up to 20
percent. Large studies of American women have shown that moderate variations
in fat intake made no difference in their breast cancer risk. The best
evidence suggests that, to be effective, dietary changes have to be sizable.

Nonetheless, research bears out a major effect of diet, not only on cancer
prevention, but also on cancer survival. Breast cancer patients who
follow lower-fat diets do tend to live substantially longer. Researchers at
the State University of New York in Buffalo tracked the diets of 953 women
who had been diagnosed with breast cancer. They then followed them to
see who did well and who did not. The results were striking. The risk of dying at any point in
time increased by 40 percent for every 1,000 grams of fat the women consumed per month.6

Let’s see what this means in practical terms:
If you were to add up all the fat in a typical American diet over the course of a month and
compare it to the amount of fat in a low-fat, pure vegetarian diet, the two
would differ by approximate 1,500 grams of fat each month. If the study’s
findings hold, that would correspond to a 60 percent increased risk of
dying at any point in time for patients following a typical American diet.

Several other studies have found much the same thing: Women with
breast cancer who eat fattier foods—meats, dairy products, and fried foods—
have greater rates of cancer recurrence and succumb more frequently than do
those whose diets are based on the lower-fat choices—vegetables, fruits,
whole grains, and beans.7 Frightening as this sort of finding may be, it shows
us a path toward reducing the need for further treatment and improves the
odds of living a life free of the tolls cancer can take.

Similar findings have emerged about prostate cancer. Men on more
health-promoting diets—that is, diets rich in vegetables, fruits, and other
low-fat foods from plant sources—are less likely to develop cancer in the
first place and, if cancer does strike, are more likely to survive it.8,9