Some studies have already found dietary fat increases risk of breast cancer in the Western countries. A new study confirms that intake of saturated fat may raise the risk.

The study led by Sieri S and colleagues from Nutritional Epidemiology Unit in Fondazione, IRCCS Istituto Nazionale dei Tumori in Milan, Italy involved 319,826 European women enrolled in European Prospective Investigation into Cancer and Nutrition.

The researchers followed participants for an average of 8.8 years during which 7119 were developed breast cancer.

They found that women in the quintile with highest intake of saturated fat were 13 percent more likely to develop breast cancer than those in the lowest quintile.

This is not the first epidemiologic study on the association between dietary fat and breast cancer. It's just that not all studies came to the agreement that dietary fat raises the risk.

There were no significant associations found between breast cancer risk and total, monounsaturated, or polyunsaturated fat, the study found.  

But surprisingly, there were an association for monounsaturated fat and an inverse correlation for polyunsaturated fat.   Monounsaturated fat most abundant in olive oil and some types of polyunsaturated fat can be very beneficial.

Of women, the positive association with saturated fat was only found in postmenopausal women and high intake was linked to a 21 percent increase in breast cancer risk, the researchers found.

The study was published in the Nov 2008 issue of American Journal of Clinical Nutrition.