East Lansing, MI—New research shows that consuming a high-fat diet during puberty may be linked to the development of breast cancer.

The results of the study, conducted by the Breast Cancer and the Environment Research Program at Michigan State University (MSU), indicate that a high-fat diet causes changes to the breast before any tumors appear, including increased cell growth and alterations in immune cells. Though these changes are made during puberty, they persist into adulthood and can cause the rapid development of precancerous lesions which may lead to breast cancer.

In the study, which was led by Sandra Haslam, physiology professor at MSU’s College of Human Medicine, pubertal mice were fed either a low-fat diet (where fat made up 12% of their daily caloric intake) or a high-fat diet (60% of daily caloric intake). They were then exposed to carcinogens that result in tumors. At weeks three and four of the study, the mice fed a high-fat diet had elevated mammary gland expression of inflammatory and growth factor genes. At 10 weeks, developing tumors in the high-fat diet mice were more proliferative and were associated with more tumor-related growth factors.

The researchers also found that a high-fat diet produced a gene signature associated with basal-like breast cancer, a subset that is more aggressive and is typically seen in younger women.

Because the mice in the study did not show any significant weight gain, the researched noted that the important factor is the fat in the diet, not overall weight. Though the evidence indicates that the damage done during puberty may be not be reversible through a low-fat diet, Haslam and her team recommend that everyone avoid a diet high in saturated animal fats as a precaution.

The research has been published in the online issue of Breast Cancer Research.

Published in WholeFoods Magazine, January 2014 (online 11/27/13)