Department of Nutrition and Food Science, Faculty of Pharmacy, University of Barcelona, Barcelona, Spain.
Am J Clin Nutr. 2010 May;91(5):1368-76. doi: 10.3945/ajcn.2009.28789. Epub 2010 Mar 24.
The genes encoding Delta(5)- and Delta(6)-desaturases (FADS1 FADS2 gene cluster) were reported to be associated with n-3 (omega-3) and n-6 (omega-6) fatty acid proportions in human plasma, tissues, and milk. Docosahexaenoic acid (DHA) can be supplied especially by dietary fish or fish oil and synthesized from alpha-linolenic acid through a pathway involving these desaturases.
We evaluated whether FADS gene variants modify the effect of maternal fish and fish-oil intake on plasma and milk DHA proportions.
FADS1 rs174561, FADS2 rs174575, and intergenic rs3834458 single nucleotide polymorphisms were genotyped in 309 women from the KOALA Birth Cohort Study in The Netherlands. Plasma was collected at 36 wk of pregnancy, and milk was collected at 1 mo postpartum. Fish and fish-oil intake was assessed by using a food-frequency questionnaire at 34 wk of pregnancy and updated for the week of milk collection. Gene-diet interactions were tested by linear regression analysis.
DHA proportions were lower in women homozygous for the minor allele than in women who were homozygous for the major allele (DHA proportions in plasma phospholipids: P < 0.01; DHA proportions in milk: P < 0.05). Fish intake ranged from 0 to 2.5 portions of fatty fish/wk, and 12 women took fish-oil supplements during pregnancy. DHA proportions in plasma phospholipids increased with increasing fish and fish-oil intake, irrespective of the genotype. DHA proportions in milk increased only with fish and fish-oil intake in the major-allele carriers.
Lower proportions of DHA in milk from women who were homozygous for the minor allele could not be compensated for by increasing fish and fish-oil intake, possibly because of limited incorporation into milk.
编码 Delta(5)-和 Delta(6)-去饱和酶（FADS1 FADS2 基因簇）的基因被报道与人体血浆、组织和乳中的 n-3（ω-3）和 n-6（ω-6）脂肪酸比例有关。二十二碳六烯酸（DHA）可以通过饮食中的鱼类或鱼油提供，也可以通过涉及这些去饱和酶的途径从α-亚麻酸合成。
我们评估 FADS 基因变异是否会改变母体鱼类和鱼油摄入对血浆和乳中 DHA 比例的影响。
在荷兰 KOALA 出生队列研究中，对 309 名女性进行了 FADS1 rs174561、FADS2 rs174575 和基因间 rs3834458 单核苷酸多态性的基因分型。在妊娠 36 周时采集血浆，在产后 1 个月时采集乳汁。在妊娠 34 周时通过食物频率问卷评估鱼类和鱼油的摄入量，并在采集乳汁的那一周进行更新。通过线性回归分析测试基因-饮食的相互作用。
与主要等位基因纯合子的女性相比，次要等位基因纯合子的女性 DHA 比例较低（血浆磷脂中的 DHA 比例：P<0.01；乳中的 DHA 比例：P<0.05）。鱼类摄入量从 0 到 2.5 份高脂肪鱼类/周不等，12 名女性在妊娠期间服用鱼油补充剂。无论基因型如何，随着鱼类和鱼油摄入量的增加，血浆磷脂中的 DHA 比例均增加。只有主要等位基因携带者的乳中 DHA 比例随着鱼类和鱼油的摄入而增加。
次要等位基因纯合子女性乳中 DHA 比例较低，可能是由于乳中 DHA 含量有限，无法通过增加鱼类和鱼油的摄入来补偿。
