中国三城市健康乳母各阶段母乳中主要多不饱和脂肪酸的含量

THE CONTENTS OF MAJOR POLYUNSATURATED FATTY ACIDS IN BREAST MILK OF THE HEALTHY LACTATING WOMEN IN THREE CITIES OF CHINA

目的测定中国城市现阶段膳食模式下健康乳母不同阶段乳汁中α-亚麻酸(ALA)、亚油酸(LA)、二十二碳六烯酸(DHA)、二十碳五烯酸(EPA)及花生四烯酸(AA)含量,以了解我国婴儿营养需求。方法采用多阶段分层随机抽样的方法,收集中国三城市乳母第0～4 d,5～11 d,12～30 d,31～60 d,61～120 d及121～180 d的乳样共计540份。乳样中ALA、LA、DHA、AA和EPA含量的测定采用气相色谱法。结果母乳中ALA、LAD、HA、AA和EPA的含量存在较大的个体差异。ALA、LA和EPA含量随泌乳时间逐渐增高;而AA和DHA的含量则随泌乳时间降低。AA与DHA之比随泌乳时间而逐渐增加,初乳、过度乳中AA:DHA比值分别为1.84和1.66,成熟乳中AA:DHA在1.93～2.54之间。结论 DHA,LA,EPA、ALA和LA的含量存在个体差异,且随哺乳时间而改变。中国乳母乳汁中多不饱和脂肪酸的含量与国外有差异,是否是由于饮食影响尚需进一步研究。

Objective To investigate the contents of alpha linolenic acid（ALA）, linoleic acid（LA）, arachidonic acid（AA）, docosahexaenoic acid（DHA）, and eicosapentaenoic acid（EPA） in breast milk of Chinese healthy mothers in different lactation stages. Methods The multi-stage stratified random sampling method was used to select 540 samples from 0-4 d, 5-11 d, 12-30 d, 31-60 d, 61-120 d and 121-180 d postpartum respectively. The high-resolution capillary gas chromatography method was used to analyze fatty acids concentrations in breast-milk. Results The contents of ALA, LA, DHA, AA and EPA in breast milk showed a wide range of standard variation in individuals during different lactation stages. ALA, LA, and EPA levels increased with lactation time, while DHA and AA levels decreased and the ratio of AA to DHA increased. The ratios of AA to DHA were 1.84 and 1.66 respectively in colostrum and transitional milk and was 1.93 to 2.54 in mature milk. Conclusion A wide range of standard variation in individuals was found for the contents of ALA, LA, DHA, AA and EPA in breast milk. The contents of major polyunsaturated fatty acids in breast milk of Chinese lactating women are different from those in other countries. Further studies are still needed to explore whether these differences are due to different dietary patterns or not.