High-fat Diet Linked to Increased Breast Cancer Risk

Monday, August 27, 2007 by: David Gutierrez, staff writer
Tags: dietary fats, breast cancer, cancer prevention

(NewsTarget) A diet high in fat significantly increases a woman's risk of developing invasive breast cancer, according to a study conducted by researchers at the National Cancer Institute in Bethesda, Maryland, and published in the Journal of the National Cancer Institute.

In the mid-1990s, the National Institutes of Health-AARP Diet and Health Study collected detailed dietary information from 188,736 postmenopausal women. After approximately four and a half years, researchers checked back with the women to see who had developed breast cancer.

Based on data collected from a 124-item "food frequency" questionnaire, the researchers concluded that women getting more than 40 percent of their calories from fat had a 15 percent higher chance of developing breast cancer than women who got only 20 percent of their calories from fat. Based on data collected from a more precise, 24-hour recall questionnaire, women with high-fat diets actually had a 32 percent higher risk of breast cancer.

"We detected a direct association between fat intake and the risk of invasive breast cancer," said lead researcher Dr. Anne Thiebaut.

The researchers found that the increased cancer risk held up regardless of whether the dietary fat came from saturated, monounsaturated or polyunsaturated sources. They did not distinguish, however, between plant and animal fats.

No difference in risk was found in women undergoing hormone replacement therapy at the beginning of the study; the researchers have noted this as an area for further examination.

Prior studies have found correlations between fat intake and cancer risk, but there is no scientific consensus yet on the mechanisms involved. Drs. Stephanie Smith-Warner and Meir Stampfer of the Harvard School of Public Health commented that it would be better to try and prevent breast cancer by controlling body fat than by controlling fat intake.

The "modest associations [between fat intake and cancer risk] stand in sharp contrast to the robust evidence for a strong link between [body fat] and the risk of postmenopausal breast cancer," they said.

"Unfortunately, this study did not track the intake of preservative chemicals routinely used in processed meat products," explained Mike Adams, a consumer health advocate and author of Grocery Warning. "It is possible that the increased risk of breast cancer is largely associated with the chemicals used in meat products and not necessarily the animal fat itself," Adams explained. "Sodium nitrite, for example, is well known to increase the risk of pancreatic cancer and brain tumors."