Saturated fatty acid composition of human milk in Israel: a comparison between Jewish and Bedouin women.

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--urban 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 lewish 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.

Role of lycopene in preventing lipid peroxidation products, in commercial infant milk formula.

OBJECTIVES: The aim of the study was to investigate whether lycopene from natural sources (tomato extract) is able to protect newborns milk formula, against oxidative damage caused by exposure to hydroxyl radicals, and is there a difference between milk substitutes from various sources. METHODS: Four commercial brands of infant milk formula: two of the formulas were dairy milk (A-d and B-d) and two were based on soy bean vegan milk (A-s and B-s), were exposed to ionizing radiation radical (·OH). Lipid peroxidation was determined by measuring malondialdehyde (MDA) using thiobarbituric acid reactive substance test (TBARS). RESULTS: When suspensions containing the four brands of formula were subjected to oxidizing media produced by ionizing radiation (hydroxyl radicals), lipid peroxidation increased linearly as a function of the irradiation dose (R = 0.99). It was found that lycopene in a concentration of 0.6 mM, reduced the radiation damage only in the soy-based formula; decrease of ∼40% of the damage achieved in B-s, and ∼20% reduction in the damage caused to A-s, significantly p < 0.01. CONCLUSIONS: Lycopene in dairy milk did not protect against hydroxyl radicals; however, lycopene found to protect against hydroxyl radicals in soy milk. This result suggests different mechanisms of radical production that arises from high iron levels present in the soy milk and involving the high-valent iron peroxo species.

Fatty acid composition of breastmilk of Israeli mothers.

We conducted this study to determine the fatty acid composition of breastmilk of Israeli women and compare it with baby milk substitutes. Samples of mature breast milk, from 29 lactating Israeli Jewish mothers were collected during feedings. Total milk lipids extracts were transmethylated and analyzed by using an improved gas-chromatographic method. About 72% of the total fatty acids in the investigated breast milk comprised oleic (18:1c; 31±4%), palmitic (16:0; 21±4%), and linoleic (18:2n-6; 20±4%) acids. Total saturated fatty acids represented 42±7% of total fatty acids. The monounsaturated fatty acids content was 33±5%, of which 94% was oleic acid, and the polyunsaturated fatty acids content was about 24±4%, of which 85% was linoleic acid. The a-linolenic acid level found in this study, 2.0±0.6%, was higher than the range of values reported for the world population (0.10-1.4%). The main fatty acids composition of the milk substitutes has very similar composition to the breast milk. Docosahexaenoic acid levels are particularly low among the population of Jewish nursing mothers in relation to the milk substitutes, containing docosahexaenoic acid in their formulations.

Role of radicals in the lipid peroxidation products of commercial infant milk formula.

Four commercial brands of infant milk formula were investigated, and the amount of shelf lipid peroxidation was determined by measuring malondialdehyde (MDA) or, more exactly, thiobarbituric acid reactive substance (TBARS) levels, which are the end products of lipid peroxidation. TBARS level, indicated by MDA concentration, was higher in the vegetarian brands. The vegetarian brands are, as expected, more prone to oxidation than dairy brands, as they contain more unsaturated fats. The introduction of formate anion diminishes the peroxide amounts initially present in the milk samples as well as those induced by radiation-induced oxidation.