Eating a high-fat diet in puberty may increase the risk of aggressive breast cancer in younger adult women, a new study has warned.
Researchers from the Michigan State University also found that this type of diet can speed up the development of breast cancer.
Utilising a preclinical model, the findings indicate that before any tumours 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.
In addition to the accelerated breast cancer development, this type of diet produces a distinct gene signature in the tumours 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," said Sandra Haslam, physiology professor in MSU's College of Human Medicine and one of the lead investigators of the project.
"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," she said.
"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," said co-lead researcher Richard Schwartz, microbiology professor and associate dean in the College of Natural Science.
"This shows the culprit is the fat itself rather than weight gain," said Schwartz.
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.
Schwartz cautioned, however, that this preliminary finding requires further investigation 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 said.
The study is published in the journal Breast Cancer Research.