Breastmilk with a high omega-6 to omega-3 fatty acid ratio induced cellular events similar to insulin resistance and obesity in 3T3-L1 adipocytes.

Abstract

An imbalance of omega (n)-3 and n-6 polyunsaturated fatty acids (PUFA) during critical periods of development may have adverse effects on the health of the newborn in later life. We hypothesized that breastmilk with higher n-6 to n-3 PUFA ratio will have higher inflammatory cytokines and initiate cellular events similar to insulin resistance and obesity. Breastmilk was collected from healthy women who gave natural birth at full term. Breastmilk fatty acids were measured using gas chromatography; samples were pooled based on the n-6 to n-3 PUFA ratio (high, medium and low), and soluble cytokines were measured. Pooled samples were used to treat 3T3-L1 cells; mRNA expression of diacylglycerol acyltransferase2, stearoyl-CoA desaturase-1, leptin and RPLPO was measured. Breastmilk with a higher ratio of n-6 to n-3 PUFA showed higher pro-inflammatory cytokines; there was a direct correlation between n-6 PUFA and pro-inflammatory cytokines. Breastmilk with a higher ratio of n-6 to n-3 PUFA increased the expression of genes involved in lipogenesis. Pro-inflammatory cytokines in breastmilk are associated with higher levels of n-6 PUFA in breastmilk and has the capacity to alter adipose tissue metabolism to likely predispose the newborn to a higher risk of obesity in later life.