Keep young girls away from high-fat diets

Girls approaching puberty may need to avoid a diet high in saturated animal fats to reduce their chances of developing breast cancer later in life.

A new study involving pubertal female mice suggests that foods high in saturated fats quickly (within 3 weeks) create permanent changes in breast tissue, including increased cell growth and alterations in the immune system, which may lead to the rapid development of precancerous lesions and, ultimately, breast cancer.

The researchers at Michigan State University and the University of North Carolina at Chapel Hill found that the high-fat diet led specifically to a high number of basal-like or triple negative breast cancers, which are particularly aggressive, growing faster and spreading to other parts of the body early. About 15% to 20% of breast cancers in the United States are this type. They are more common among women aged younger than 50 years and generally have a poorer prognosis than other types of breast cancer.

The researchers also found that the changes to the breast tissue occurred whether or not the mice gained weight from the high-fat diet, indicating that the association is with the dietary fat itself rather than with increased body mass.

Because the research suggests that the breast tissue changes are permanent, switching to a low-fat diet later in life may not undo the damage.

Half of all breast cancer deaths in the US occur in women aged younger than 50 years, suggesting the need for more information and education targeted to this younger audience.

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