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【medical-news】摄取某种脂肪酸似乎可以改善早产
CHICAGO – Preterm infant girls who received a high amount of dietary docosahexaenoic acid (DHA; an omega-3 fatty acid) had higher measures of neurodevelopment than preterm girls who received a standard amount of DHA, but this effect was not seen among preterm boys, according to a study in the January 14 issue of JAMA.
Infants born before 33 weeks’ gestation are at high risk of developmental disorders and learning disabilities. An inadequate nutrient supply during the newborn period is believed to contribute to this poor developmental outcome, according to background information in the article. DHA deficiency is hypothesized to result in poor neurodevelopmental outcomes in preterm infants, but uncertainty exists about the benefit of dietary DHA.
Maria Makrides, B.Sc., B.N.D., Ph.D., of Women’s and Children’s Hospital and Flinders Medical Centre, Adelaide, Australia and colleagues conducted a randomized controlled trial to determine the effect of high-dose dietary DHA on neurological outcomes in preterm infants. The study included infants born at less than 33 weeks’ gestation from five Australian hospitals. Of the 657 infants enrolled, 93.5 percent completed the 18-month follow-up.
The infants were randomized to high-DHA (approximately 1 percent total fatty acids) compared with standard DHA (approximately 0.3 percent total fatty acids) from day 2 to 4 of life until the infants reached their expected date of delivery. The infants received DHA from either breast milk or infant formula. Lactating mothers allocated to the high-DHA group were asked to consume six 500-mg DHA-rich tuna oil capsules per day to achieve a high breast milk DHA concentration. If supplementary formula was required, infants were given a high-DHA preterm formula. Mothers with infants allocated to the standard-DHA group were asked to consume six 500-mg placebo soy oil capsules that did not change the fat content or fatty acid composition of their milk.
To measure neurological development, the researchers used the Bayley Mental Development Index (MDI), which evaluates memory, problem solving, early number concepts and language. They found that the average MDI score did not differ between the high-DHA and standard-DHA groups, but that the MDI score among girls fed the high-DHA diet was significantly higher than among girls fed the standard-DHA diet, while the MDI score among boys did not differ between groups.
“The lack of responsiveness of boys to the intervention is puzzling, and the reasons are unclear …,” the authors write.
Additional analyses indicated that, overall, fewer infants had significantly delayed mental development with high-DHA diets compared with standard DHA and that there were fewer girls with mild and significant mental delay in the high-DHA group relative to the standard-DHA group, but there were no differences among the boys.
“Infants ranged in gestational age from 23 to 33 weeks and, thus, had a range of nutritional stressors, organ immaturity, and [illnesses]. Despite this, the intervention was sufficiently robust to consistently elicit an improvement in the MDI scores of girls and may point the way for higher-dose interventions in future studies. Given the lack of an alternative therapy for cognitive delay in this group of infants and the apparent safety of the current dose of DHA, further studies are warranted,” the authors conclude.
芝加哥 -- 据1月14日刊JAMA上的一则研究披露，那些摄取高剂量食物性二十二碳六烯酸（即DHA；这是一种欧米茄-3脂肪酸）的早产女婴，其神经系统发育的改善值比那些接受标准含量DHA的早产女婴的改善值要更高，但是这一效果却不见于早产男婴之中。
那些在妊娠33周之前出生的婴儿有很高的风险会出现发育和学习方面的障碍。根据文章的背景资料，在新生儿时期营养供应的不足被认为是造成发育不良后果的原因。有人提出了DHA缺乏是导致早产婴儿神经系统发育不良这一后果的假设，但食物性DHA是否对早产儿具有裨益仍然不肯定。
Women’s and Children’s Hospital and Flinders Medical Centre, Adelaide, Australia的Maria Makrides, B.Sc., B.N.D., Ph.D.及其同僚开展了一项随机化并设有对照组的试验，旨在确定高剂量的食物性DHA对早产婴儿神经系统发育的结果是否有影响。该研究所接纳的是在妊娠33周之前出生的婴儿，他们来自5家澳大利亚的医院。在纳入研究的657名婴儿中，有93.5%的婴儿完成了为期18个月的随访。
这些早产婴儿被随机指派接受高剂量的DHA（大约占1%的总体脂肪酸）或标准剂量的DHA（大约占0.3%的总体脂肪酸）。他们在出生后的第2天到第4天开始服用DHA，直到他们正常的预产期为止。这些婴儿获得DHA的渠道是母乳或婴儿配方奶。被分派至高剂量DHA组的哺乳母亲每天需要服用6粒富含DHA的金枪鱼油（500毫克/粒）胶囊以达到母乳中有高浓度DHA的目的。如果要求补充性的配方奶的话，这些婴儿会被喂以含有高剂量DHA的早产儿配方奶。那些被指派到服用标准剂量DHA小组的婴儿的母亲每日会服用6粒安慰剂（每粒含有500毫克的大豆油）胶囊，其结果不会改变母乳中的油脂含量或脂肪酸的成分。
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作者:admin@医学,生命科学 2011-08-14 05:11
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