The association between different kinds of fat intake and breast cancer risk in women.

So far several animal and case-control studies have confirmed this hypothesis that dietary fat increases the risk of breast cancer. However, cohort studies have not shown this relationship. The aim of this study was to review the studies on the relationship between dietary fat intake and breast cancer risk among women. Electronic database PubMed and Google Scholar were searched using the key words: Breast cancer, dietary fat, serum estrogen, saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). The evidence of the studies regarding to the association of total and subtypes of fat intake with breast cancer risk are inconsistent. Several studies have shown that, among several types of fat, SFAs and w-3 PUFA intake are associated with an increased and reduced risk of breast cancer, respectively. The relationship between MUFAs intake and breast cancer risk is conflicting. Narrow ranges of fat intake among populations, measurement errors, high correlation between specific types of dietary fat, the confounding variables like body fatness and high-energy intake and other dietary components such as fiber and antioxidants might be probable explanations for these inconsistent results. Although we are not at a stage where we can justifiably advise women to reduce their fat intake to decrease the risk of developing breast cancer, it seems the current guidelines to lower total fat consumption and recommendation to consumption of unsaturated fats such as MUFAs and w-3 fatty acids and also reduction of SFAs (meat and dairy products) intake to avoid heart disease is also useful for breast cancer risk.