Eating too much monounsaturated fat and saturated fat may increase risk of breast cancer whereas eating high amounts of long chain polyunsaturated omega-3 fatty acids may reduce the risk, according to a study recently published in Nutrition and Cancer.
A.K. Sczaniecka of The Fred Hutchinson Cancer Research Center , Cancer Prevention Program in Seattle , Washington , USA and colleagues found the associations between different fats and risk of breast cancer in postmenopausal women aged 50 to 76 years at baseline who participated in the VITamins and Lifestyle Cohort.
For the study, participants completed a food frequency questionnaire in 2000 to 2002 and 772 cases of breast cancer cases were identified during the follow-up.
Women in the highest quintile of total monounsaturated fatty acids were 61 percent more likely to be diagnosed with breast cancer, compared to those in the lowest quintile. The risk increase was particularly high among those who had highest intake of myristoleic and erucic acids.
The highest intake of total saturated fatty acids was associated with 47 percent increased risk of breast cancer, compared to the lowest intake. The risk increase was particularly strong among those with highest intakes of palmitic, margaric, and stearic acids.
Margaric acid or otherwise known as heptadecanoic acid is a saturated fatty acid found only in the fat and milk fat of ruminants.
Total trans fat and polyunsaturated fatty acid intake were not associated with breast cancer.
However, of trans fatty acids, linolelaidic acid was positively associated with risk of breast cancer; and of polyunsaturated fatty acids, eicosapentaenoic and docosahexaenoic acids were inversely associated with the risk. Linoelaidic acid is an omega-6 trans fatty acid found in partially hydrogenated vegetable oils. Eicosapentaenoic and docosahexaenoic acids are commonly found in fish oil.
The researchers concluded "Our findings show that fatty acids are heterogeneous in their association with postmenopausal breast cancer risk.
