The benefits of breastfeeding may be somewhat lower for the median reader of this blog than the median late 1990s Belarusian. You probably have access to cleaner water, more/better medical care and newer formula that includes things like DHA, ARA, and more nucleotides.
Why somewhat? It’s plausible to me that even just the lack of DHA would give the overall RCT results.
On priors I’d expect formula to be worse: there are strong evolutionary reasons for breast milk to be the ideal food, while formula is limited by our capability to understand what babies need. If we were missing something important in formula to where babies were dying early we’d notice, but as the effect size gets smaller the chance we notice goes way down. But running studies and updating our practices based on them is still a factor, and DHA is mandatory (in the US) now. I’d still guess that an RCT today would show IQ impacts, but this is based on priors about how hard this problem is, our civilizational capacity, and the incentive structures for formula manufacturers, and not primarily on an RCT in quite a different environment.
Why somewhat? It’s plausible to me that even just the lack of DHA would give the overall RCT results.
Yeah, that seems plausible to me, too. I don’t think I want to claim that the benefits are “definitely slightly lower”, but rather that they’re likely at least a little lower but I’m uncertain how much. My best guess is that the bioactive stuff like IgA does at least something, so modern formula still isn’t at 100%, but it’s hard to be confident.
Why somewhat? It’s plausible to me that even just the lack of DHA would give the overall RCT results.
On priors I’d expect formula to be worse: there are strong evolutionary reasons for breast milk to be the ideal food, while formula is limited by our capability to understand what babies need. If we were missing something important in formula to where babies were dying early we’d notice, but as the effect size gets smaller the chance we notice goes way down. But running studies and updating our practices based on them is still a factor, and DHA is mandatory (in the US) now. I’d still guess that an RCT today would show IQ impacts, but this is based on priors about how hard this problem is, our civilizational capacity, and the incentive structures for formula manufacturers, and not primarily on an RCT in quite a different environment.
Yeah, that seems plausible to me, too. I don’t think I want to claim that the benefits are “definitely slightly lower”, but rather that they’re likely at least a little lower but I’m uncertain how much. My best guess is that the bioactive stuff like IgA does at least something, so modern formula still isn’t at 100%, but it’s hard to be confident.