A high fat diet increases the risk of the most common form of breast cancer by a fifth, an Italian study has found.
Heavy consumption of saturated fat had a bigger impact, raising the risk of hormone-sensitive breast cancer by 28%.
Fatty diets also made it more likely for a woman to develop breast cancer marked by a defective HER2 gene.
A majority of breast cancers are driven by the female hormone oestrogen, and of these most are also sensitive to the hormone progesterone.
“It’s difficult to unpick which elements of a person’s diet impact upon their breast cancer risk”
Researchers who studied data on 10,000 patients found an association between fat consumption and breast cancer in these women. The same link was not seen in women whose cancers were neither hormone-sensitive nor HER2-positive.
The findings, from the Epic breast cancer study involving more than 300,000 women in 10 European countries, are reported in the Journal Of The National Cancer Institute.
The authors, led by Dr Sabina Sieri from the National Tumour Institute in Milan, said: “The results of this prospective study on a large heterogeneous population of European women indicate that a high-fat diet increases BC risk and, most conspicuously, that high saturated fat intake increases risk of receptor-positive disease, suggesting saturated fat involvement in the etiology (causes) of receptor-positive BC.”
Eluned Hughes, senior manager for information at Breakthrough Breast Cancer, said: “This is an important finding because it’s difficult to unpick which elements of a person’s diet impact upon their breast cancer risk.
“We know that 40% of breast cancers could be prevented by changes to lifestyle such as being regularly active, maintaining a healthy weight and limiting alcohol consumption but this study provides us with further insight into the specific role of saturated fat intake and certain types of breast cancer,” she said.
“Whilst we are learning more and more each day about the environmental, genetic and lifestyle factors that affect breast cancer risk, it is not yet possible to predict who will get breast cancer, and for women who have been diagnosed with the disease, we can’t yet say what caused it,” she added.
- Read the full study paper in the Journal Of The National Cancer Institute