Mothers with diets high in omega 6 fats, are likely to increase their offspring's risk of developing breast cancer, however, consuming canola oil during pregnancy and breast-feeding may help cut the risk.
In this study, researchers fed one group of mice a diet containing corn oil and another group a diet containing canola oil, then recorded the incidence of breast cancer and changes to breast cancer regulating genes in the offspring.
Fifty percent of corn oil is made up of omega 6 polyunsaturated fats, which have previously been linked to increased rates of breast cancer, while canola oil has only 20 percent omega 6 fats.
Omega 3 fats, which have been linked to lower cancer risk, vary as well. Corn oil has less than .5 percent omega 3 fats while canola oil has 10 percent.
"We're seeing changes in gene expression up to five months after the animals were exposed to a diet containing omega 6 fatty acids during gestation and lactation," said W. Elaine Hardman, Ph.D., associate professor of biochemistry and microbiology at Marshall University School of Medicine and lead author of the study.
"The only explanation is that during gestation and lactation, the mother's diet must be imprinting the genes of the baby," Hardman added.
The researchers found that the total tumour weight, number of glands with tumours and fraction of mice with tumours were higher in those whose mothers who were fed corn oil.
The canola oil group displayed up-regulated genes for CCAAT-enhancer binding protein beta (CEBPß), a transcription factor involved in breast cancer differentiation, and Early growth response 1 (Egr1), a tumour suppressor gene.
The offspring of the canola oil-fed mothers showed higher levels of omega 3 fats in the inguinal fat pad, breasts and liver.
The study was presented at the American Association for Cancer Research's Seventh Annual International Conference on Frontiers in Cancer Prevention Research.