Narrator: This is Science Today. Epidemiologists studying breast cancer have long associated a high fat diet with an increased risk of the disease. But Virginia Ernster, a professor of epidemiology at the University of California, San Francisco says enthusiasm for the high dietary fat hypothesis was dampened after it was found the diets between women who developed breast cancer and those who didn't were not that different.
Ernster: One of the reasons that maybe the dietary fat studies have not proven very fruitful has to do with our inability to evaluate diet early in life when it may be the most important. And we haven't really been able to adequately study young girl's diets and then follow them over decades to see whether that very early diet and a high fat diet at that point or some other diet is associated with an increased risk of breast cancer.
Narrator: Recent studies have found diets high in mono-saturated fats, such as olive oil, reduce a woman's risk of breast cancers.
Ernster: So that certainly bears investigation...that's something that we can do something about.
Narrator: For Science Today, I'm Larissa Branin.