INS and breast cancer: Systematic review of cohort studies and meta-analyses showed an inverse association between BC and n-3 PUFA and n-3 :  n-6 ratio, especially when confirmed in biological samples, such as adipose tissue, erythrocyte membranes, serum, and plasma (Rose, 1993; Simonsen et al., 1998), possibly because of reduced inflammation, carcinogenic, and oxidative stress and enhanced insulin sensitivity (Larsson et al., 2004), and recently shown reduced obesity trajectory (Simopoulos, 2016).