生物与医学2017ncbi.nlm.nih.gov
母乳对 IQ、脑容量和白质发育的影响 (2010)
Impact of breast milk on IQ, brain size and white matter development (2010)
入门 · 约 45 分钟读完前置知识：流行病学基础、统计学显著性、神经影像学基础
导读
这篇 2010 年的研究探讨母乳喂养对儿童智力、脑容量和白质发育的影响，发现母乳摄入比例与言语智商相关，且这种关联在男孩中更明显，涉及总脑容量和白质容量等指标。但该研究为观察性设计，样本量小，因果结论并不牢固。
HN 关注点：母乳喂养与智力的因果关系是否成立，讨论焦点集中在研究方法缺陷（未控制母亲智商和社会经济地位等混杂因素）以及母乳喂养被忽视的成本与权衡。
HN 评论精选
这几条评论里：质疑 1 补充 2 亲历 1
质疑批评该研究样本小、非实验设计、未控制基本混杂变量，结论不可靠。
我不明白为什么要把 7 年前的研究翻出来，它并不是一项特别好、有趣或结论明确的研究。问题包括：1. 样本量小；2. 显著性只在某个子群体中出现——把人群按足够多的方式切分，几乎总能得到假阳性；3. 不是实验设计；4. 没有控制收入或父母健康状况等简单因素。
c3534l查看英文原文
I'm not sure why this study from 7 years ago is being dug up because it's not a particularly good, interesting, or definitive study. Some problems with it: 1. Small sample sizes. 2. Significance was only found in one subset of the population. Given enough ways to divide up groups of people, you will almost always get false positives. 3. Not an experimental design. 4. The study did not control for simple factors like income or the health of the parent.
亲历亲历者指出母乳喂养收益微小难测，但成本（母亲负担、金钱、身体损伤）巨大，呼吁更坦诚的权衡讨论。
作为新手父母，我真希望有更现实的关于母乳喂养益处的科普。从我能看到的荟萃分析来看，目前的科学答案是：可能有影响，但小到难以可靠测量，且可能被其他干预措施淹没。这很重要，因为母乳喂养的成本常被忽视：它把不成比例的负担压在我妻子身上，考虑到她的工作时间，我们每天为此花费几十到几百美元；许多女性还要忍受数月的伤痛和感染。也许这一切都值得，但我希望关于这种权衡能有更好的讨论。
JackC查看英文原文
As a recent parent I would love it if there was more realistic health information for parents about the benefits of breastfeeding. As best I can tell from metastudies (which I'm totally unqualified to read), the scientific answer right now is: there may be some effect, but if so it's too small to reliably measure and may be swamped by other interventions. (I could be wrong! That's why I want better info.) (Compare to, say, the advice to have infants sleep on their backs to prevent SIDS, or the HPV vaccine, which have clear and measurable health impacts at a population level.) This matters because breastfeeding has costs that tend to be ignored. Just from personal experience, it pushes disproportionate work onto my wife in a way that's hard to correct for and detracts from parenting. And given that she's working full time, it's also a huge investment of resources -- if you take her work time into account, we're spending tens or hundreds of dollars a day for this. And many women get injuries and infections, soldiering through months of agony for that health benefit that may or may not exist. Setting aside the health of the parents (and we shouldn't, that's an easy trap), breastfeeding uses a lot of resources that could go toward other interventions for the child. Maybe it's all worth it? But I wish there was a better conversation about the tradeoffs.
补充引用后续研究证明母乳喂养与智力的关联主要是社会经济地位等混杂因素所致。
这项研究没有控制母亲智商和社会经济地位。后续研究表明，母乳喂养与认知发育之间的关联很大程度上源于混杂效应（尤其是高 SES 母亲更可能母乳喂养）：BMJ Open 的结论指出'母乳喂养对儿童神经发育的大部分报告效应源于混杂'。另一项配对研究显示：匹配前母乳喂养几乎与所有结局正相关，但匹配并校正多重检验后，13 项结局中仅 1 项（3 岁儿童多动）保持显著，5 岁时无任何显著差异。
rayiner查看英文原文
This study does not control for maternal IQ or socio-economic status. Later studies show that much of the link between breastfeeding and cognitive development is due to confounding effects (in particular, higher SES mothers are more likely to breastfeed): http://bmjopen.bmj.com/content/3/8/e003259 > Conclusions Much of the reported effect of breastfeeding on child neurodevelopment is due to confounding. It is unlikely that additional work will change the current synthesis. Future studies should attempt to rigorously control for all important confounders. Alternatively, study designs using sibling cohorts discordant for breastfeeding may yield more robust conclusions. See also: http://pediatrics.aappublications.org/content/early/2017/03/23/peds.2016-1848 > RESULTS: Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children’s hyperactivity (difference score, –0.84; 95% confidence interval, –1.33 to –0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years. The linked study also yields some odd results: > In the total group %EBM correlated significantly with Verbal IQ (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with grey matter. A meta-study that adjusted for maternal IQ only (but not socioeconomic status, which independently correlates with higher rates of breastfeeding) found a very small effect on IQ: https://www.ncbi.nlm.nih.gov/pubmed/26211556 > We included 17 studies with 18 estimates of the relationship between breastfeeding and performance in intelligence tests. In a random-effects model, breastfed subjects achieved a higher IQ [mean difference: 3.44 points (95% confidence interval: 2.30; 4.58)]. We found no evidence of publication bias. Studies that controlled for maternal IQ showed a smaller benefit from breastfeeding [mean difference 2.62 points (95% confidence interval: 1.25; 3.98)]. In the meta-regression, none of the study characteristics explained the heterogeneity among the studies.
补充指出研究只测量少数变量，忽视了母婴情感联结这一重要维度。
这页有 112 条评论，我搜'emotion'零命中，只有一条提到'bonding'。对人类状况的任何科学评估都存在视野狭窄的问题——这些研究只考虑了数千个变量中的少数几个。母婴之间的情感联结是母乳喂养的重要因素，这是不需要科学验证的常识，尽管从那个角度做研究会很有意思。
all_usernames查看英文原文
There are at this time 112 comments on this page. I searched for "emotion" and got zero hits, and only one comment mentioned "bonding." A problem with any scientific assessment of the human condition is the narrow focus, and these studies only take into account a few variables out of thousands. Emotional bonding between mother and child is a huge factor in breastfeeding -- that's common sense that doesn't require scientific validation, although it would be very interesting to see studies from that perspective.
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