Ratnayake W M, Chen Z Y
Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada.
Lipids. 1996 Mar;31 Suppl:S279-82. doi: 10.1007/BF02637091.
The presence of trans fatty acids in human milk may be a concern because of their possible adverse nutritional and physiological effects on the recipient infant. The mother's diet is the source of human milk trans fatty acids, and since these fatty acids are prevalent in many common foods of the Canadian diet, the trans fatty acid content and the fatty acid composition of Canadian human milk were measured by gas-liquid chromatography coupled with silver nitrate-thin layer chromatography. In samples obtained from 198 lactating mothers across Canada, the average percentage of total trans (sum of t18:1, t18:2, and t18:3) was 7.2% of breast milk fatty acids with a range of 0.1-17.2%. Analysis of t18:1 isomer distribution indicated that partially hydrogenated vegetable oils are the major source of these trans fatty acids in human milk, whereas contribution from dairy products appeared to be relatively minor. Linoleic and alpha-linolenic acid levels were inversely related to the total trans fatty acids, indicating that the elevation of trans fatty acids in Canadian human milk is at the expense of n-3 and n-6 essential fatty acids. Levels of arachidonic and docosahexaenoic acids did not correlate with their parent fatty acids, indicating that it might be difficult to elevate the levels of n-6 and n-3 c20-22 polyunsaturated fatty acids in breast milk by increasing levels of linoleic and alpha-linolenic acids in the mother's diet.
母乳中反式脂肪酸的存在可能令人担忧，因为它们可能对接受母乳的婴儿产生不良营养和生理影响。母亲的饮食是母乳中反式脂肪酸的来源，由于这些脂肪酸在加拿大饮食的许多常见食物中普遍存在，因此采用气相色谱法结合硝酸银 - 薄层色谱法对加拿大母乳的反式脂肪酸含量和脂肪酸组成进行了测定。在从加拿大各地198名哺乳期母亲采集的样本中，总反式脂肪酸（t18:1、t18:2和t18:3的总和）平均占母乳脂肪酸的7.2%，范围为0.1 - 17.2%。对t18:1异构体分布的分析表明，部分氢化植物油是母乳中这些反式脂肪酸的主要来源，而乳制品的贡献似乎相对较小。亚油酸和α-亚麻酸水平与总反式脂肪酸呈负相关，这表明加拿大母乳中反式脂肪酸的升高是以n-3和n-6必需脂肪酸为代价的。花生四烯酸和二十二碳六烯酸的水平与其母体脂肪酸不相关，这表明通过增加母亲饮食中亚油酸和α-亚麻酸的水平来提高母乳中n-6和n-3 20 - 22多不饱和脂肪酸的水平可能很困难。
