学 术 报 告 厅
译者:王少玲(哈尔滨医科大学公共卫生学院,哈尔滨 150001)
母乳喂养对婴儿和母亲的长期影响
Longterm effects of breastfeeding on the infant and mother
摘 要:越来越多的证据表明,母乳喂养对婴儿有长期有利影响。最重要的是可改善认知发育,降低免疫相关疾病(如1型糖尿病和炎性肠病)和儿童期肿瘤的发病率。另一重要益处在于降低母亲患乳腺癌的风险。
关键词:母乳喂养;长期影响;认知功能;生长;心血管影响;免疫系统;过敏反应;母体效应
1 前言
母乳喂养对孩子具有多种好处并可影响许多生理机制。不只是短期影响,而且会影响生命后期。许多健康益处显示出剂量应答关系,即母乳喂养持续时间越长则益处越大。世界卫生组织推荐的最佳纯母乳喂养持续时间为6个月1。这是经过系统评价来自发达国家和发展中国家的研究,比较不同母乳喂养时间婴儿的生长、发育、发病率和死亡率得出的结果2。这篇文章的目的是简要综述母乳喂养对婴儿和母亲健康的影响,着重强调其长期影响。母乳喂养对儿童期肥胖的影响见本期第26页。
2 方法
检验母乳喂养的影响主要是根据观察研究,实际上是无规则的将婴儿随机分为母乳喂养和配方喂养。目前方法中的难题是可能存在误差原因,如混杂设计、相反的因果关系和选择偏倚,因为社会地位和母亲受教育程度强烈地关系到母乳喂养的持续时间和一些研究结果。但最近15年已通过改进设计和更好地控制有关的混杂设计进而改善观察研究的质量。
3 认知发育
许多研究发现母乳喂养与认知发育相关。对6月龄和15岁之间儿童进行的一项meta-分析报道了控制可能的混杂因素之后3.2 IQ点的全部影响3。这种影响对早产儿较强。这与母乳喂养持续时间存在明显的剂量-反应关系,而且影响似乎不依赖于结果测定时所处的年龄。一项研究认为这种影响可持续到生命后期,因为已经发现母乳喂养持续时间和智力呈正相关,其中一组人群为男性(平均年龄18.7),另一组人群为男性和女性(平均年龄27.2)4。两组采用不同的智商测验。
母乳喂养对精神功能影响的最可能合理解释为母乳与婴儿配方相比含有较多的长链多不饱和脂肪酸(LCPUFA),尤其是n-3脂肪酸和二十二碳六烯酸(DHA),DHA在婴儿期聚积在神经膜中5-7。早产儿较低的LCPUFA状况支持这一机制。尽管认知功能对个体影响不大,它可能对总体水平具有重要影响。
4 生长
母乳喂养婴儿通常表现出不同于配方喂养婴儿的生长模式。母乳喂养婴儿的体重增加较低,一些研究中发现身长增加也受影响。此外,12月龄的母乳喂养婴儿脂肪一般少于配方喂养婴儿8,9。关于母乳喂养婴儿生长缓慢的不利后果未有报道。
5 免疫系统及其功能障碍
母乳含有许多免疫因子,使婴儿被动预防感染。最重要的免疫相关因子为B细胞和T细胞、巨噬细胞、中性粒细胞、分泌性免疫球蛋白A(sIgA)、细胞活素类、双歧因子、溶菌酶、低聚糖和乳铁蛋白10,11。母乳喂养还能刺激婴儿自身免疫系统:母乳喂养婴儿的胸腺较大12,尿中sIgA浓度较高13,接种某种疫苗后也应答较高的抗体水平14。似乎这种刺激具有长期效应。
母乳喂养婴儿传染病的发病率低于配方喂养婴儿。母乳喂养能最有效防止胃肠道感染,呼吸道感染也减少15,16。另有报道可防止3岁之前的尿路感染和中耳炎10,17。
母乳喂养在过敏反应发生中的作用通常被视为最显著的优势之一。母乳喂养可防止牛奶过敏反应18,对其他过敏性疾病如特应性皮炎和哮喘的效果不甚明确。在一项系统评价母乳喂养和支气管哮喘预期性研究的meta分析中报道母乳喂养可使哮鸣和哮喘发病率降低30%。如果有哮喘家族史则效果更明显19。最近的结论认为母乳喂养似乎对特应性疾病具有正面效应,并且这种效应在特应性疾病家族更显著20。然而,另有两项研究报道母乳喂养没有完全效应。按家族过敏史将儿童分组,观察到双亲致敏对儿童有保护效应,反之双亲不致敏儿童发生特应性皮炎的风险有轻微增加21,22。
腹部疾病或持续性谷蛋白敏感性肠病是一种免疫性疾病。如果在母乳喂养时逐渐在饮食中添加含谷蛋白食品可降低发病风险23。
在其他免疫相关性疾病中,有报道母乳喂养可降低克隆病和溃疡性结肠炎风险,但母乳喂养是否为这些疾病发生的主要原因还不清楚24,25。还有报道母乳喂养防止发生多发性硬化和类风湿性关节炎26。利用供者人乳与配方乳比较似乎前者可降低早产儿发生坏死性小肠结肠炎的风险27。
6 1型糖尿病
遗传和环境因素导致1型糖尿病的发生。大量研究报道了母乳喂养的保护效应,而使用配方乳和添加食品似乎可增加患病风险24。此外,早期快速生长也增加1型糖尿病的风险,并且不依赖其他的危险因素,早期使用配方乳28, 29。一项多个实验中心进行的研究发现,从未接受母乳喂养的非母乳喂养的儿童在调整生长模式后可使其1型糖尿病的风险率降低40%29。有研究认为母乳中的LCPUFA可改善β细胞抵抗30。
7 心血管疾病
因母乳中含有胆固醇,母乳喂养婴儿血清胆固醇浓度高于配方喂养婴儿,而一旦母乳喂养结束则不存在这种现象。母乳喂养的婴儿成年后血清胆固醇水平较低31。meta分析报道母乳喂养则生命后期收缩压较低的结果与此一致。但全身差别仅为1.1 mmHg,临床意义不大32。另有个别研究报道母乳喂养有减小动脉扩张性的不利效应33。此外,两项新研究发现,母乳喂养影响心血管疾病发病率无确实根据34, 35。
8 肿瘤
两项meta分析认为,母乳喂养可轻微降低儿童白血病36和其他儿童期肿瘤37风险率。母乳喂养对所有的肿瘤具有相似的保护效应,因在大多数研究中不能排除母乳的非特异性效应或系统偏差。
9 对母亲的影响
防止乳腺癌是母乳喂养对母亲健康最明显的影响。一项meta分析显示,每12个月母乳喂养乳腺癌的相对危险度下降4.3%,而每产一胎其发病的相对危险度减低7%38。
参考文献:
1. WHO, 2002, The optimal duration of exclusive breastfeeding. Report of an expert consultation.
2. Kramer MS, and Kakuma R, 2002, The optimal duration of exclusive breast feeding. A systematic review.
3. Anderson JW, Johnstone BM and Remley, DT. Breast-feeding and cognitive development A meta-analysis, Am J Clin Nutr, 1999, 70525-535.
4. Mortensen EL, Michaelsen KF, Sanders SA and Reinisch JM. The association between duration of breastfeeding and adult intelligence. JAMA, 2002, 287 2365-2371.
5. Lauritzen L, Hansen HS, Jorgensen MH and Michaelsen KF. The essentiality of long chain n-3 fatty acids in relation to development and function of the brain and retina. Prog Lipid Res. 2001,401-94.
6. Michaelsen KF, Lauritzen L, Jrgensen MH and Mortensen EL. Breastfeeding and brain development, Scand. J Nutr, 2003, 47147-151.
7. SanGiovanni JP, Berkey CS, Dwyer JT and Colditz GA. Dietary essential fatty acids, long-chain polyunsaturated fatty acids and visual resolution acuity in healthy full term infants a systematic review. Early Hum Dev, 2000, 57165-188.
8. Michaelsen KF, Petersen S, Greisen G and Thomsen BL. Weight, length, head circumference and growth velocity in a longitudinal study of Danish infants. Dan Med Bull, 1994, 44577-585.
9.Dewey KG. Growth characteristics of breast-fed compared to formula-fed infants. Biol Neonate, 1998, 7494-105.
10. Heinig MJ and Dewey KG. The advantages of breast feeding infants a critical review. Nutrition Research Reviews, 1996, 989-110.
11. Hanson LA, Korotkova M, Lundin S. The transfer of immunity from mother to child. Ann N Y Acad Sci, 2003, 987199-206.
12. Hasselbalch H, Jeppesen DL, Engelmann MD, Michaelsen KF and Nielsen MB. Decreased thymus size in formula-fed infants compared with breastfed infants. Acta Paediatr, 1996, 851029-1032.
13. Goldblum R, Hanson L and Brandtzaeg P. The mucosal defence system. In Immunological Disorders in Infants and Children. 3rd edit. E. Stiehm, Ed. 1996, 159-199.
14. Saunders. Philadelphia PA. Hahn-Zoric M, Fulconis F, Minoli I, Moro G, Carlsson B, Bottiger M, Raiha N and Hanson LA. Antibody responses to parenteral and oral vaccines are impaired by conventional and low protein formulas as compared to breast-feeding. Acta Paediatr Scand. 1990, 79 (12) 1137-1142.
15. Howie PW. Protective effect of breastfeeding against infection in the first and second six months of life, Adv Exp Med Biol. 2002, 503141-147.
16. Oddy WH, Sly PD and de Klerk NH. Breast feeding and respiratory morbidity in infancy a birth cohort study. Arch Dis Child. 2003, 88 224-228.
17. León-Cava N, Lutter C, Ross J and Martin L. 2002, Quantifying the benefits of breast feeding a summary of theevidence, (www.linkagesproject.orgmedia publications Technical%20Reports BOB. pdfLin kages. 2004).
18. Halken S. Prevention of allergic disease in childhood clinical and epidemiological aspects of primary and secondary allergy prevention. Pediatr Allergy Immunol. 2004, 16 4-5,9-32.
19. Gdalevich M, Mimouni D and Mimouni M. 2001, Breast-feeding and the risk of bronchial asthma in childhood: a systematic review with meta-analysis of prospective studies. J Pediatr, 139 261-6.23. Davis MK. 2001, Breastfeeding and chronic disease in childhood and adolescence. Pediatr Clin North Am, 48 125-141, ix.
20. van Odijk J, Kull I and Borres MP. Breastfeeding and allergic disease: a multidisciplinary review of the literature (1966-2001) on the mode of early feeding in infancy and its impact on later atopic manifestations. Allergy, 2003, 58833-843.
21. Laubereau B, Brockow I and Zirngibl A. Effect of breast-feeding on the development of atopic dermatitis during the first 3 years of life-results from the GINI-birth cohort study. J Pediatr, 2004, 144 602-607.
22. Stabell BC, Wohlfahrt J and Aaby P. Breastfeeding and risk of atopic dermatitis, by parental history of allergy, during the first 18 months of life. Am J Epidemiol, 2004, 160 217-223.
23. Ivarsson A, Hernell O, Stenlund H and Persson LA. Breast-feeding protects against celiac disease. Am J Clin Nutr. 2002, 75 914-921.
24. Davis MK. Breastfeeding and chronic disease in childhood and adolescence. Pediatr Clin North Am, 2001, 48125-141, ix.
25. Klement E, Cohen RV, Boxman J, Joseph A and Reif S. Breastfeeding and risk of inflammatory bowel disease a systematic review with meta-analysis. Am J Clin Nutr. 2004, 801342-1352.
26. Hanson L, Silfverdal SA and Stromback L. The immunological role of breast feeding. Pediatr Allergy Immunol 2001, 12 Suppl 1415-19.
27. McGuire W and Anthony MY. Donor human milk versus formula for preventing necrotising enterocolitis in preterm infants systematic review. Arch Dis Child Fetal Neonatal Ed, 2003, 88 F11-F14.
28. Hyppnen E, Kenward MG and Virtanen S M. Infant feeding, early weight gain, and risk of type 1 diabetes. Childhood Diabetes in Finland (DiMe) Study Group. Diabetes Care, 1999, 221961-1965.
29. EURODIAB Substudy 2 Study Group, 2002, Rapid early growth is associated with increased risk of childhood type 1 diabetes in various European populations. Diabetes Care, 251755-1760.
30. Das UN. Can perinatal supplementation of long-chain polyunsaturated fatty acids prevent diabetes mellitus? Eur J Clin Nutr. 2003, 57 218-226.
31. Owen CG, Whincup PH, Odoki K, Gilg JA and Cook DG. Infant feeding and blood cholesterol a study in adolescents and a systematic review. Pediatrics, 2002, 110 597-608.
32. Owen CG, Whincup PH, Gilg JA and Cook DG. Effect of breast feeding in infancy on blood pressure in later life systematic review and meta-analysis. BMJ, 2003, 3271189-1195.
33. Leeson CP, Kattenhorn M, Deanfield JE and Lucas A. Duration of breast feeding and arterial distensibility in early adult life: population based study. BMJ, 2001, 322643-647.
34. Martin RM, Davey SG, Mangtani P, Tilling K, Frankel S and Gunnell D. Breastfeeding and cardiovascular mortality the Boyd Orr cohort and a systematic review with meta-analysis. Eur Heart J. 2004, 25778-786.
35. Rich-Edwards JW, Stampfer MJ and Manson JE. Breastfeeding during infancy and the risk of cardiovascular disease in adulthood. Epidemiology, 2004, 15550-556.
36. Kwan ML, Buffler PA, Abrams B and Kiley VA. Breastfeeding and the risk of childhood leukaemia A meta-analysis. Public Health Rep. 2004, 119521-535.
37. UK Childhood Cancer Study Investigators, 2001, Breastfeeding and childhood cancer, Br J Cancer, 85.
38. Collaborative Group on Hormonal Factors in Breast Cancer, Breast cancer and breast feeding collaborative reanalysis of individual data from 47 epidemiological studies in 30 countries,including 50302 women with breast cancer and 96973 women without the disease,Lancet,2002, 360187-195.