High-fat diet early may boost breast cancer risk later

"Overall, our current research indicates that avoiding excessive dietary fat of this type may help lower one’s risk of breast cancer down the road," says Richard Schwartz. (Credit: G.L. Kohuth)

A study with mice suggests that a high-fat diet during puberty could speed up the development of breast cancer.

The findings, published online in the journal Breast Cancer Research, indicate that before any tumors appear, there are changes in the breast that include increased cell growth and alterations in immune cells. These changes persist into adulthood and can lead to the rapid development of precancerous lesions and ultimately breast cancer.

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A high-fat diet also produces a distinct gene signature in the tumors consistent with a subset of breast cancers known as basal-like that can carry a worse prognosis.

“This is very significant because even though the cancers arise from random mutations, the gene signature indicating a basal-like breast cancer shows the overarching and potent influence this type of diet has in the breast,” says Sandra Haslam, professor of physiology at Michigan State University.

“Cancers of this type are more aggressive in nature and typically occur in younger women. This highlights the significance of our work toward efforts against the disease.”

It’s the fat, not the weight gain

“It’s important to note that since our experimental model did not involve any weight gain from the high-fat diet, these findings are relevant to a much broader segment of the population than just those who are overweight,” says Richard Schwartz, microbiology professor. “This shows the culprit is the fat itself rather than weight gain.”

Early evidence indicates that the fat, which in this case was saturated animal fat, could potentially have permanent effects even if a low-fat diet is introduced later in life.

The preliminary finding requires further investigation, Schwartz cautions, and doesn’t indicate with certainty that humans will be affected in the same way.

“Overall, our current research indicates that avoiding excessive dietary fat of this type may help lower one’s risk of breast cancer down the road,” he says. “And since there isn’t any evidence suggesting that avoiding this type of diet is harmful, it just makes sense to do it.”

The research is funded by the National Institute of Environmental Health Sciences and the National Cancer Institute.

Source: Michigan State University