Summary

 Background: Breast milk is well established as the ideal source of nutrition for infants. Mature human breast milk generally contains 3.5–4.5% lipids comprising mostly triacylglycerols. In general, the fat composition of maternal human milk in developing countries shows higher levels of saturated fats, reflecting diets rich in carbohydrates.

Objectives: To determine the profile of unsaturated fatty acids in the breast milk of two populations in southern Israel, Jewish and rural tent-dwelling Bedouin women.

Methods: This study involved 48 lactating Israeli mothers, 29 Jewish and 19 Bedouin (16–20 weeks postpartum), whose full-term infants were fed exclusively with breast milk. Total milk lipid extracts were transmethylated and analyzed by using an improved gas chromatographic method.

Results: The breast milk of the Bedouin women contained significantly higher levels of total major saturated fatty acids, lauric acid and palmitic acid (45.2 ± 4.7% vs. 41.0 ± 5.6%, P = 0.005; 5.2 ± 2.1 vs. 6.8 ± 2.0%, P = 0.03; and 22.7 ± 2.4 vs. 20.6 ± 3.8%, P = 0.02) respectively. No difference was found in the myristic acid level between the groups. The level of stearic acid was significantly higher in the Jewish group compared to the Bedouin group (5.7 ± 1.1 vs. 5.1 ± 1.1%, P = 0.04). There was a linear correlation between the levels of C14:0 and C12:0 in the Bedouin and Jewish groups respectively (R = 0.87, R = 0.82, P < 0.001).

Conclusions: Higher levels of saturated fatty acids were measured in the breast milk of Bedouin women, an economically weaker population. The results emphasize the importance of diet among lactating women and its influence on milk quality.