Further Study Urged of Fat’s Link to Cancer

Recent research strongly suggests that the amount of fat in a woman’s diet does not affect her risk of developing breast cancer, but two UC San Diego scientists argue that it is too early to simply dismiss the long-suspected link.

In October, researchers in Boston provided the strongest evidence yet that there is no link between dietary fat intake and the incidence of breast cancer. They monitored the diets of 89,494 Boston-area nurses since the 1980s.

“We find no evidence to support a positive relationship between dietary fat and the incidence of breast cancer,” Harvard University Prof. Graham Colditz said Friday during a breast cancer symposium in La Jolla sponsored by the UC San Diego Cancer Center Foundation. “And we see absolutely no evidence that decreasing dietary fat brings any reduction in the incidence of breast cancer,” Colditz said.

But, in a separate session Friday, UCSD researcher Elizabeth Barrett-Connor questioned whether studies of younger women will generate findings that can be applied to older, post-menopausal women.

Barrett-Connor’s concern is driven by a relatively small study of about 500 women in Rancho Bernardo, including 15 of whom eventually developed breast cancer. Barrett-Connor has studied the health and dietary habits of the Rancho Bernardo group since the early 1970s.

In each of the 15 cases where breast cancer developed, “every single fat that we measured was reported higher” in dietary surveys conducted early in the women’s lives, Barrett-Connor said.

Barrett-Connor acknowledged that her study group was “absurdly small,” but she maintained that the continuing study is important because it highlights the physical differences between older and younger women.

“This is not an easy thing to study,” Barrett-Connor said. Breast cancer incidence could be affected by when a woman begins to menstruate, when a woman’s first child is born, diet, family history, alcohol consumption and the onset of menopause, Barrett-Connor said.

Further research might show that “breast cancer in older (menopausal) women is a different disease” than among younger women, Barrett-Connor said.

During Friday’s meeting, UCSD biology professor Paul Saltman also questioned the wisdom of dismissing fat as a suspect.

Saltman maintained that fat should remain an important concern for researchers because fat is omnipresent in modern Western diets.