不同年龄阶段小鼠脑聚集二十二碳六烯酸及脂肪酸去饱和酶的变化

【目的】 探讨生命早期不同年龄阶段脑摄取、聚集二十二碳六烯酸(DHA)(C22:6n-3)及相关去饱和酶的变化。 【方法】 使用6~8周龄清洁级C57BL/6J雌性小鼠,分别给予n-3 多不饱和脂肪酸(n-3 PUFAs)缺乏饲料和含n-3 PUFAs饲料喂养6周,然后雌雄合笼交配繁殖,新生仔鼠分别于生后7、21 d和42 d时取血、脑和肝脏。采用甲酯化-气相色谱分析对血浆、脑和肝脏中脂肪酸谱进行分析;采用荧光定量PCR方法对脑和肝脏中脂肪酸去饱和酶1(FADS1)和脂肪酸去饱和酶2(FADS2)基因mRNA表达进行检测。 【结果】 对不同年龄小鼠组织脂肪酸的比较发现,脑中DHA和总n-3 PUFAs含量在两种不同饲料组均随年龄增加而升高;而肝中的含量则随年龄增加而降低。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7、21 d和42 d时脑和肝脏中DHA和总n-3 PUFAs含量均显著升高;升高的程度在脑组织中随年龄增加而降低,而在肝脏组织中则不随年龄变化。对不同年龄段FADS表达的比较发现,FADS1和FADS2 mRNA在脑组织中的表达量于42 d时显著高于7 d和21 d,而在肝组织中的表达量于各年龄段之间无显著性差异。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7 d和21 d时脑组织FADS1和FADS2表达水平显著降低,而42 d时的表达无变化;肝组织中这两种酶mRNA水平在7 d和21 d时无变化,42 d时FADS1显著降低。 【结论】 发育期脑对DHA的聚集需求随着年龄增大而逐渐减少;FADS在脑中的表达水平随年龄增大而升高。同时,饲料n-3 PUFAs缺乏状态对脑聚集DHA以及FADS的影响在年龄小时更明显。     

脂肪酸水平与儿童注意缺陷多动障碍的关系及膳食补充n-3类脂肪酸的影响

目的研究儿童注意缺陷多动障碍(ADHD)与非ADHD儿童体内脂肪酸水平差异及膳食补充n-3类脂肪酸对ADHD儿童体内脂肪酸水平的影响作用。方法在1 555名2~5年级学生中筛选出ADHD儿童79名,取50名非ADHD儿童作为对照,采集静脉血分析其脂肪酸差异。采用随机对照试验(RCT)原则,将ADHD儿童随机分为干预组和对照组,采用不同浓度的n-3多不饱和脂肪酸(PUFAs)膳食补充干预3个月,观察干预后脂代谢改善情况。结果ADHD儿童血红细胞膜的饱和脂肪酸(SFAs)中的C15∶0、C16∶0、C20∶0,单不饱和脂肪酸(MUFAs)中的C15∶1、C18∶1、C20∶1、C24∶1及PUFAs中的亚油酸C18∶2 n-6(LA)明显高于非ADHD组儿童(P0.05);花生四烯酸C20∶4 n-6(AA)、二十碳五烯酸C20∶5 n-3(EPA)及C22∶4(n-6)低于非ADHD组儿童。ADHD儿童补充n-3PUFAs后,体内α-亚麻酸C18∶3 n-3(ALA)、C24∶0、二十二碳六烯酸C22∶6 n-3(DHA)及n-3PUFAs水平显著提高,n-6PUFAs、n-6/n-3比例则显著降低。结论ADHD与非ADHD儿童体内的脂肪酸组成存在差异,补充n-3类脂肪酸可提高ADHD儿童体内n-3类脂肪酸水平,同时降低n-6/n-3比例。     

不同过敏体质母亲母乳中PUFAs与免疫因子的差异及相互性研究

目的 探讨不同过敏体质母亲母乳中多不饱和脂肪酸(PUFAs)和免疫因子的改变,同时分析体内多不饱和脂肪酸组成对免疫因子的影响。方法 随机选取符合标准的80例母亲进入课题,产后2周和4周收集母乳,问卷调查母亲过敏史。采用高效毛细气相色谱分析技术检测母乳中脂肪酸浓度,分别采用酶联免疫吸附法和BioPlex悬液芯片技术测定母乳中免疫因子sCD14(soluble CD14)、IgE和IL-1β(interleukin-1β)、Eotaxin浓度。结果 过敏性皮炎母亲2周母乳ALA(α -linolenic acid,ALA)和n-6 PUFAs代谢系数(n-6LCPUFAs/LA)低于非过敏母亲,2周和4周母乳中LA/ALA(linoleic acid,LA)均高于非过敏母亲(P<0.05)。过敏性鼻炎母亲2周母乳ALA、EPA(eicosapentaenoic acid,EPA)、DHA(docosahexaenoic acid,DHA)含量均低于非过敏母亲(P<0.05)。无论过敏母亲还是非过敏母亲,母乳中多种n-3PUFAs(ALA、EPA、C20:3n-3)与sCD14呈正相关,与IgE负相关(P<0.05);母乳中多种n-6PUFAs(C18:3n-6,C20:3n-6,C22:2n-6)与sCD14呈负相关,与Eotaxin和IL-1β正相关(P<0.05)。结论 不同过敏体质母亲与非过敏母亲母乳多不饱和脂肪酸组成存在差异;体内多不饱和脂肪酸组成对免疫因子的分泌具有重要影响。     

饮食n-3脂肪酸对小鼠脑脂类中多不饱和脂肪酸构成的影响

【目的】观察饮食鱼油n-3多不饱和脂肪酸(n-3 PUFAs)对脑内不同脂类中PUFAs构成的影响。【方法】使用C57BL/6J雌性小鼠,在胎儿期和幼年期分别给予不同种类高脂饲料(18%脂肪,供能比为36%)喂养-高脂豆油饲料、高脂鱼油饲料和高脂豆油:鱼油(5∶1)混合饲料,以正常饲料(6%脂肪来自豆油,供能比为12%)为对照,时间为4个月。采用薄层层析分离脑组织中各主要脂类成份,然后采用甲酯化-气相色谱分析对各脂类成份中的脂肪酸进行测定。【结果】鱼油饲料喂养改变了小鼠脑内主要脂类中PUFAs的构成。在磷脂中,虽然5种PUFAs在各饲料组之间差异均无显著性(P>0.05),但二十二碳六烯酸(DHA)/花生四烯酸(AA)(1.94±0.41)以及n-3/n-6 PUFAs比值(2.31±0.75)在鱼油组较其它三组显著升高(P<0.05);在甘油一和二酯中,与豆油组相比,鱼油组和豆油:鱼油混合组LA含量(0.31±0.09%,0.65±0.58%)降低,而鱼油组DHA/AA(2.60±1.66)以及n-3/n-6 PUFAs比值(2.31±0.75)升高(P<0.05);在甘油三酯中,与豆油组相比,鱼油组和豆油:鱼油混合组AA含量(1.62±0.53%,1.12±0.36%)和EPA含量(0.98±0.58%,1.34±0.31%)显著降低,而DHA/AA比值(1.14±0.21,1.46±0.58)升高(P<0.05),但DHA含量在三组之间无差异(P>0.05);在游离脂肪酸中,5种PUFAs在各饲料组之间无差异(P>0.05)。【结论】饮食鱼油n-3 PUFAs摄入增多虽然不影响脑内DHA的聚积,但改变了DHA/AA以及n-3/n-6PUFAs的比值。甘油酯类可能是脑摄取、聚积DHA的主要直接来源之一。     

孕期不同膳食模式对膳食脂肪酸含量及母初乳脂肪酸组成的影响

【目的】研究中国两种不同膳食模式地区膳食脂肪酸(fatty acid,FA)含量的差异,并探讨这种差异对母初乳脂肪酸组成的影响。【方法】对传统内陆膳食(常州)和海洋膳食(温州)地区孕晚期孕妇进行7d膳食调查,根据《2002中国食物成份数据》中的食物脂肪酸含量数据计算出膳食脂肪酸含量;并通过随访这些孕妇收集5d母初乳样本,采用高效毛细气相色谱分析技术检测5d母初乳的脂肪酸组成。【结果】常州与温州两地孕母摄入的膳食种类存在差异,温州地区孕母摄入的海洋食品远大于常州地区。常州地区孕母膳食脂肪酸中亚油酸(linoleic acid,LA)和α-亚麻酸(α-linolenic acid,ALA)含量均高于温州地区;而二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳五烯酸(eicosap-entaenoic acid,EPA)含量均低于温州地区;花生四稀酸(arachidonic acid,AA)含量则未见显著差异。两地膳食脂肪酸组成中LA、ALA、AA以及DHA的差异同样反应在5d母初乳中,但两地5d母初乳中的EPA含量差异无显著性。【结论】膳食模式不同的两个地区,其孕母的膳食脂肪酸含量存在差异,且这种差异可在母初乳脂肪酸组成中得到体现。     

饲料鱼油n-3多不饱和脂肪酸含量变化对小鼠脑聚集DHA及去饱和酶表达的影响

[目的] 探讨饲料中鱼油n-3多不饱和脂肪酸(n-3 PUFAs)含量对小鼠脑组织中二十二碳六烯酸(DHA)的影响,同时观察肝、脑组织中△5和△6去饱和酶表达的变化. [方法] 使用3～4周龄C57BL/6J雌性小鼠,分别给予4种不同含量的鱼油n-3 PUFAs(占总脂肪酸含量的百分比分别为2.8%、5.4%、10.0%和23.0%)饲料喂养3个月,饲料中n-6/n-3 PUFAs比值分别为20 :1、10 :1、5:1、1:1,以n-3 PUFAs缺乏饲料为对照.应用气相色谱分析对血浆、肝脏和脑组织中脂肪酸进行测定;采用实时荧光定量PCR(RT-PCR)对小鼠肝脏和脑组织中△5和△6去饱和酶mR-NA表达进行分析. [结果] 与n-3 PUFA缺乏饲料组相比,含鱼油n-3 PUFAs饲料喂养组小鼠血浆、肝脏及脑组织中的DHA及总n-3 PUFAs含量均明显增加,而花生四烯酸(AA)及总n-6 PUFAs含量降低;同时AA/DHA比值以及∑n-6/∑n-3 PUFAs比值降低.饲料中鱼油n-3 PUFAs含量变化对脑聚集DHA的影响存在着一定的剂量一效应关系.进一步发现,在肝组织中,n-3 PUFAs饲料喂养各组△6去饱和酶mRNA表达量较对照组均显著降低;而在脑组织中,只有n-6/n-3PUFAs(1:1)组△5、△6去饱和酶mRNA表达量较对照组显著降低. [结论] 脑组织中DHA的聚集随饲料中鱼油n-3 PUFAs含量的升高而增加;脑中△6和△5去饱和酶的表达在高含量鱼油n-3 PUFAs摄入时才受到抑制,提示膳食摄入DHA需要在很高含量时,才有可能满足脑的需求.     

舟山地区母乳中DHA及AA含量分析

【目的】观察舟山地区母乳中脂肪酸成份及其含量,为母乳喂养提供依据。【方法】采用石英毛细管柱气相色谱法,对舟山地区67例健康产妇母乳中脂肪酸成份进行测定。【结果】产妇成熟母乳中亚油酸(linoleicacid,LA)为(20.03±3.11)%,a-亚麻酸(a-linolenic acid,LNA)为(2.48±0.55)%,二十二碳六烯酸(docosahexaenoic acid,DHA)的含量为[(0.67±0.21)%]。初乳中花生四烯酸(arachidonic acid,AA)和DHA的含量显著高于成熟母乳中的含量。【结论】研究表明舟山地区母乳中LA和LAN的含量较高,且由于膳食中鱼和海产食物较多,故母乳中DHA含量较高,初乳中含有较高含量的AA和DHA,十分有利新生婴儿的生长发育。     

EPA、DHA对人单核细胞PGE_2、IL-6分泌及IL-6 mRNA表达的影响

EPA(eicosapentaenoic acid,n-3)和DHA(docosahexaenoic acid,n-3)是n-3多不饱和脂肪酸(polyunsaturated fatty acids,PUFAs),主要富含于鱼油等海产品中。上世纪有学者发现格陵兰岛爱斯基摩人,日本人因膳食富含n-3PUFAs的海产品,其心肌梗死、慢性炎性病、自身免疫性病发生率都很低,由此引起人们关注。之后针对一些炎症和自身免疫性疾病,如类风湿性关节炎[1],溃疡性结肠炎[2],肾病[3],支气管哮喘[4]等的临床实验也发现n-3PUFAs有良好治疗效果。研究发现n-3PUFAs改善炎性及免疫性疾病的作用可能与抑制单核/巨噬细胞分泌的许多炎症介…     

n-3多不饱和脂肪酸对肥胖小鼠食欲调节因子表达的影响

【目的】 探讨n-3多不饱和脂肪酸(n-3 PUFAs)对饲料诱导肥胖小鼠食欲调节因子表达的影响。 【方法】 使用3~4周龄C57BL/6J雄性小鼠,随机分为3组,每组15只,分别给予两种高脂饲料(脂肪含量为34.9%,供能比为60%)-n-6PUFAs(来源于葵花籽油)饲料和n-3PUFAs(来源于鱼油)饲料喂养3个月;以正常脂饲料(脂肪含量为4.3%,供能比为10%)作为诱导肥胖鼠的对照。小鼠禁食12 h后,麻醉状态下心脏取血、脑和性腺周围脂肪。血浆瘦素含量测定采用酶联免疫分析法;脂肪组织瘦素及下丘脑瘦素受体、神经肽Y(NPY) 和促阿片-黑素细胞皮质素原(POMC)mRNA表达采用实时荧光定量PCR进行。 【结果】 两组高脂饲料诱导的肥胖小鼠体重和血浆瘦素浓度均高于正常脂饲料组小鼠,但n-3PUFAs高脂饲料组肥胖小鼠在两项指标的增高程度显著低于n-6PUFAs高脂饲料组肥胖小鼠。与正常脂饲料喂养小鼠相比,n-6PUFAs高脂饲料诱导肥胖小鼠脂肪组织瘦素和下丘脑瘦素受体、POMC mRNA表达水平显著升高,而NPY mRNA水平降低;n-3PUFAs高脂饲料诱导肥胖小鼠的上述4种基因mRNA表达则未发生变化。 【结论】 n-3PUFAs可减轻肥胖状态下瘦素及其受体、NPY、POMC等食欲调节因子表达的异常,在肥胖发生中起着积极作用。     

肥胖小鼠DNA甲基化改变以及n-3多不饱和脂肪酸的影响作用

【目的】 探讨肥胖状态下脂肪组织基因组DNA甲基化及甲基转移酶表达改变以及n-3多不饱和脂肪酸(n-3 PUFAs)的影响作用。 【方法】 使用30只3~4周龄C57BL/6J雄性小鼠,随机分为3组,每组10只。小鼠分别给予两种高脂饲料(脂肪含量为34.9%,供能比为60%)-n-6 PUFAs(脂肪来源于葵花籽油)饲料和n-3 PUFAs(脂肪来源于鱼油)饲料喂养14周;以正常脂饲料(脂肪含量为4.3%,供能比为10%)(脂肪来源于葵花籽油)为对照。喂养结束后对小鼠脂肪组织基因组DNA总甲基化以及甲基转移酶(DNMTs)进行测定。 【结果】 与正常脂饲料喂养小鼠相比,两组高脂饲料诱导肥胖小鼠的脂肪组织DNA总甲基化程度均明显升高,但n-3 PUFAs高脂饲料组升高的程度显著低于n-6 PUFAs组。n-6 PUFAs高脂饲料诱导肥胖小鼠的脂肪组织DNMT1、DNMT3a和DNMT3b的表达均显著高于正常脂饲料组小鼠,而n-3 PUFAs高脂饲料喂养小鼠脂肪组织中这3种酶的表达无变化。 【结论】 肥胖状态下脂肪组织基因组DNA甲基化程度升高;鱼油n-3 PUFAs具有抑制DNA甲基化的作用。     

注意分散型注意缺陷多动障碍学生智测结果分析

【目的】 通过探讨注意分散型注意缺陷多动障碍(attention deficit hyperactivity disorder,ADHD)学生智力测试智商水平以及分测验结构,以了解这一人群的智商发育情况。 【方法】 采用韦氏儿童智力量表中国修订本(WISC-CR)对107例注意分散型ADHD儿童进行智力测定。 【结果】 107例注意分散型ADHD儿童韦氏智力测试总智商(intelligence quotient,IQ)为(97.86±15.01),呈正态分布,操作IQ优于言语IQ(P＜0.001);言语IQ与操作IQ存在不平衡者(即言语与操作IQ差值≥15者)共48例,占44.86%,以操作IQ>言语IQ多见(40例)。 【结论】 注意分散型ADHD学生中,智商发展不平衡者较多见,在分析智测结果时,重视儿童在测试时的行为表现以及分项测试结果,淡化总-IQ,合理引导儿童及家长可能更具有现实意义。     

Discrepancies in dietary intakes and plasma concentrations of fatty acids according to age among Japanese female dietitians

OBJECTIVE: To clarify the influences of age on dietary intakes and plasma concentrations of fatty acids (FAs) in Japanese female dietitians. SUBJECTS AND METHODS: In autumn 1996, we estimated dietary FA intakes based on 7 day weighed diet records and analyzed plasma FA concentrations in 79 healthy Japanese female dietitians, and investigated their relationships with age, dividing into three age groups (young (32-42 y), middle-aged (43-50 y) and elderly (51-66 y)). RESULTS: Dietary intakes of total FA, saturated FAs, monounsaturated FAs, n-3 polyunsaturated FAs (PUFAs) and alpha-linolenic acid (18:3n-3) were significantly highest in the middle-aged group, and lowest in the elderly. Similar trends were observed for dietary intakes of n-6 PUFAs and linoleic acid (18:2n-6), but there were no differences with regard to eicosapentaenoic acid (EPA; 20:5n-3), docosahexaenoic acid (DHA; 22:6n-3) and n-3 highly unsaturated FAs (HUFAs=EPA+22:5n-3+DHA). On the other hand, plasma concentrations of all FAs except for arachidonic acid (20:4n-6) demonstrated positive correlations with age. Moreover, plasma concentrations of EPA in all age groups, DHA in the elderly and n-3 HUFAs in the middle-aged and the elderly were all positively correlated with dietary intakes. CONCLUSIONS: We should take into account the influence of age on dietary habit and lipid metabolism when interpreting associations between dietary FA intakes and plasma FA concentrations.     

The (n-3) fatty acid dose, independent of the (n-6) to (n-3) fatty acid ratio, affects the plasma fatty acid profile of normal dogs

The purpose of this study was to determine whether the dose of (n-3) fatty acids (FA) administered, independent of the relative ratio of (n-6) to (n-3) FA in the food, influences plasma FA composition in dogs. Healthy female, geriatric beagles (7-10 y old) were fed foods containing (n-6) to (n-3) FA ratios of either 40.0:1 or 1.4:1 for 12 wk (study 1) or 36 wk (study 2). In study 3, beagles were fed food with the same 1:1 ratio of (n-6) to (n-3) FA, but with increasing concentrations of (n-6) and (n-3) FA. Plasma FA concentrations were measured after completing the feeding studies. In studies 1 and 2, dogs fed fish oil-enriched food with a high (n-3) FA concentration had higher plasma total (n-3) FA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) concentrations and lower plasma total (n-6) FA, linoleic acid, and arachidonic acid concentrations than dogs fed corn oil-enriched food with a low (n-3) FA concentration (P < 0.001). Both inclusion of fish oil (P < 0.001) and increased food intake independent of treatment effects increased the plasma DHA (P = 0.05) concentration. Furthermore, constancy of the dose of (n-3) FA administered over long periods of time was necessary to maintain plasma levels of total (n-3) FA, EPA, and DHA. In study 3, up to certain dietary concentrations (6.3 g total (n-3) FA/kg food for DHA and 9.8 g total (n-3) FA/kg food for EPA), the dose of (n-3) FA administered, independent of the (n-6) to (n-3) FA ratio, determined the plasma (n-3) FA composition. Results from our studies indicate that approximately 175 mg DHA/(kg body weight . d) is required to attain maximum plasma levels of DHA.     

铅污染对儿童血液生化及其智力的影响

【目的】 探讨铅污染对儿童健康的影响,为进一步做好预防儿童铅中毒工作提供科学依据。 【方法】 选某蓄电池厂子校父母一方铅暴露者(实验一组),父母未铅暴露者(实验二组)及对照组学生各61名配对。 【结果】 实验一、二组学生的血铅(PbB)、尿铅(PbU)、红细胞游离原卟啉(FEP)显著高于对照组,而血红蛋白(Hb)和平均红细胞血红蛋白浓度(MCHC)显著降抵(P<0.01),表明长期铅暴露可引起学生体内铅蓄积量增加,干扰扑啉代谢和Hb合成。实验一组低智商检出率(14.75%)显著高于其它两组(P<0.01)。母亲铅暴露者智商(IQ)为98.59,低于父亲铅暴露者(IQ=101.91)和实验二组(IQ=105.20),并显著低于对照组(IQ=106.16,P<0.01)。 【结论】 长期铅暴露的儿童,血红蛋白有降低的趋势;同时铅暴露也是影响学生智力发育的危险因素之一,督促政府和社会给予铅污染对儿童健康影响以极大地关注,采取有效措施保护儿童身心健康。     

Diet (n-3) polyunsaturated fatty acid content and parity interact to alter maternal rat brain phospholipid fatty acid composition

Low tissue levels of (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid [DHA, 22:6(n-3)], are implicated in postpartum depression. The effects of 1-4 sequential reproductive cycles on maternal brain phospholipid fatty acid composition were determined in female rats fed diets containing alpha-linolenic acid (ALA), containing ALA and pre-formed DHA (ALA+DHA), or lacking ALA (low-ALA). Virgin females, fed the diets for commensurate durations served as a control for reproduction. Whole-brain total phospholipid composition was determined at weaning by TLC/GC. A single reproductive cycle on the low-ALA diet decreased brain DHA content by 18% compared to ALA primiparas (P < 0.05), accompanied by incorporation of docosapentaenoic acid ((n-6) DPA, 22:5(n-6)) to 280% of ALA primiparas (P < 0.05). DHA was not further decreased after subsequent cycles; however, there was an additional increase in (n-6) DPA after the second cycle (P < 0.05). Brain DHA of virgin females fed the low-ALA diet for 27 wk decreased 15% (P < 0.05), but was accompanied by a more modest increase in (n-6) DPA than in parous low-ALA dams (P < 0.05). Virgin females and parous dams fed the diet containing ALA+DHA exhibited only minor changes in brain fatty acid composition. These observations demonstrate that brain DHA content of adult animals is vulnerable to depletion under dietary conditions that supply inadequate (n-3) PUFAs, that this effect is augmented by the physiological demands of pregnancy and lactation, and that maternal diet and parity interact to affect maternal brain PUFA status.     

Erythrocyte membrane n-3 polyunsaturated fatty acids are inversely associated with the presence and progression of nonalcoholic fatty liver disease in Chinese adults: a prospective study

Previous studies have shown that high-dose supplementation with n-3 polyunsaturated fatty acids (PUFAs) may benefit patients with nonalcoholic fatty liver disease (NAFLD), but the association of n-3 PUFAs with NAFLD among individuals with normal diets is only speculative. We investigated the cross-sectional and prospective associations between n-3 PUFAs and NAFLD in Chinese adults. This community-based prospective study included 3049 men and women (40–75 years) in Guangzhou, China, whose participants completed an NAFLD ultrasound evaluation and erythrocyte PUFA tests. A total of 2660 participants underwent the second NAFLD evaluation approximately 3 years later. α-Linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in erythrocytes were measured by gas chromatography. After adjusting for potential confounders, we observed inverse associations between DHA, DHA + EPA, total n-3 PUFAs and the presence of NAFLD in the cross-sectional analysis. The adjusted odds ratios (95% confidence interval) of NAFLD for the highest (vs. lowest) tertile were 0.74 (0.61, 0.90) for DHA, 0.82 (0.67, 1.00) for EPA, 0.73 (0.60, 0.88) for DHA + EPA and 0.74 (0.61, 0.91) for total n-3 PUFAs  (all P values≤0.05). Over the average 3.12 years of follow-up, higher levels of DHA was associated with an improvement of NAFLD. The hazard ratio of improved NAFLD for the highest tertile was 1.18 (95% CI 1.09, 1.33) for DHA. Pathway analyses showed that favorable associations may be mediated by improvements in inflammatory markers (e.g., interleukin 1 beta and tumor necrosis factor alpha-like). Erythrocyte membrane n-3 PUFAs are inversely associated with the presence and progression of NAFLD in Chinese adults. ClinicalTrials.gov NCT03179657.     

脂肪酸去饱和酶基因多态性对儿童脂肪酸构成和认知记忆的影响

目的探讨脂肪酸去饱和酶（FADS）多态性对学龄儿童红细胞膜多不饱和脂肪酸(PUFAs)构成和认知记忆的影响。方法对参与补充DHA随机对照试验的8～12岁的南雄市坪田镇小学生进行基线问卷调查收集一般情况、膳食资料、体格测量并采集空腹血。采用数字广度测试和威斯康星卡片分类测试评估认知记忆功能。测定红细胞膜脂肪酸构成,提取血凝块DNA进行FADS4个位点的多态性分析。结果共调查106名三至五年级在校小学生,男生62人,女生44人,平均年龄为（9.17±1.03）岁。不同红细胞膜DHA的含量构成的调查对象认知记忆功能差异无统计学意义（均P＞0.05）。FADS的4个位点相互间符合H-W平衡（0.409～0.970）。FADS rs174561基因型不同C18∶2、C18∶3（n-6）、C20∶5、总n-3、AA/LA、EPA/ALA的比例差异有统计学意义（P＜0.01或P＜0.05）。混合线性模型分析结果发现,完成分类数、概念化水平数、概念化水平mm+Mm基因型者高于MM基因型者（均P＜0.05）,mm+Mm基因型者总错误数和总错误率低于MM基因型者（均P＜0.05）。结论FADS多态性可影响学龄儿童体内PUFAs构成和认知记忆功能。     

A quantitative analysis of prenatal intake of n-3 polyunsaturated fatty acids and cognitive development

Although a rich source of n-3 polyunsaturated fatty acids (PUFAs) that may confer multiple health benefits, some fish also contain methyl mercury (MeHg), which may harm the developing fetus. U.S. government recommendations for women of childbearing age are to modify consumption of high-MeHg fish to reduce MeHg exposure, while recommendations encourage fish consumption among the general population because of the nutritional benefits. The Harvard Center for Risk Analysis convened an expert panel (see acknowledgements) to quantify the net impact of resulting hypothetical changes in fish consumption across the population. This paper estimates the impact of prenatal n-3 intake on cognitive development. Other papers quantify the negative impact of prenatal exposure to MeHg on cognitive development, and the extent to which fish consumption protects against coronary heart disease mortality and stroke in adults. This paper aggregates eight randomized controlled trials (RCTs) comparing cognitive development in controls and in children who had received n-3 PUFA supplementation (seven studies of formula supplementation and one study of maternal dietary supplementation). Our analysis assigns study weights accounting for statistical precision, relevance of three endpoint domains (general intelligence, verbal ability, and motor skills) to prediction of IQ, and age at evaluation. The study estimates that increasing maternal docosahexaenoic acid (DHA) intake by 100 mg/day increases child IQ by 0.13 points. The paper notes that findings were inconsistent across the RCTs evaluated (although our findings were relatively robust to changes in the weighting scheme used). Also, for seven of the eight studies reviewed, effects are extrapolated from formula supplementation to maternal dietary intake.     

Effects of n-3 polyunsaturated fatty acid supplementation in pregnancy on maternal and fetal erythrocyte fatty acid composition

OBJECTIVE: The aim of this study was to assess the effects of fish oil supplementation in pregnancy on maternal erythrocyte fatty acid composition at different stages of pregnancy and in the post-partum period, and on neonatal erythrocyte fatty acid composition. DESIGN: A double-blind, randomised, placebo-controlled study. SETTING:: Subiaco, Western Australia. SUBJECTS: In all, 98 women booked for delivery at St John of God Hospital, Subiaco, were recruited from private rooms of obstetricians. In total, 83 women and their healthy full-term babies completed the study. INTERVENTION: Women received either 4 g of fish oil (n=52) (56% docosahexaenoic acid (DHA) and 28% eicosapentaenoic acid (EPA) or placebo (olive oil) (n=46) per day from 20 weeks gestation until delivery. MAIN OUTCOME MEASURES: Erythrocyte phospholipid fatty acids were measured in maternal peripheral blood at 20, 30 and 37 weeks of pregnancy and at 6 weeks post partum, and from cord blood collected at birth. RESULTS: Compared to the control group, maternal EPA and DHA were significantly higher in the fish oil group at 30 and 37 weeks gestation, and remained elevated at 6 weeks post partum (P<0.001). The proportions of n-6 polyunsaturated (arachidonic acid, 22:3n-6 and 22:4n-6) were significantly lower in the fish oil supplemented group at the same time periods (P<0.001). Similarly, the proportions of EPA and DHA were significantly higher (P<0.001), and those of n-6 polyunsaturated fatty acids arachidonic acid, 20:3n-6, 22:3n-6 and 22:4n-6 were significantly lower (P<0.001), in erythrocytes from neonates in the fish oil group, compared to those in the control group. CONCLUSION: Fish oil supplementation from 20 weeks of pregnancy until birth is an effective means of enhancing n-3 fatty acid status of both mothers and neonates. Furthermore, the changes in maternal erythrocyte fatty acid composition are retained until at least 6 weeks post partum. It is essential to assess the effects of concomitant decreases in arachidonic acid status before any dietary recommendations can be made. SPONSORSHIP: The study was supported by grants from the NH & MRC and Raine Medical Research Foundation, Australia.