Beautiful and fascinating milk. As a neonatologist, a baby doctor, for decades I focused my research on nutrition in babies. Milk was thus always at the forefront of my attention. And there was always something interesting to discover or investigate about it.
Just this year, in 2022, the announcement of a USA national shortage of milk formula for babies was truly bizarre and unimaginable! Who would have thought that that could happen in a so-called advanced country like ours? A reminder to us all that milk is truly an essential food for babies and that it cannot be easily replaced.
What’s smarter than the two brain lobes of the smartest scientist? A poetic scientist once proclaimed that the two lobes that normally produce milk are far superior to the brain lobes of the smartest scientist. That’s close to the truth, since milk production is one of the most perplexing mysteries in biology. Brilliantly producing greatly needed essential nutrients, chemicals, good microbes, antibodies, enzymes, immune factors and a host of chemical signals. Which allow babies to grow perfectly! What else can produce such a perfect concoction?
“Cow’s milk is for calves!” Thus declared Dr. Frank Oski, world-renowned pediatrician. He was making a significant point about keeping cow’s milk for cows, and human milk for humans. Plus, by implication, goat’s milk for little goats, pig’s milk for piglets. Because there are huge differences among the various mammalian milks, and each milk is specific to each species!
“牛奶应该属于小牛.” 世界知名的儿科医生——弗兰克 奥斯奇(Frank Oski) 医生用这样一句话有力地指出这样的事实：牛奶应该专属于小牛，人类的母乳才属于人类。不仅如此，羊奶应该专属于小羊，猪奶应该专属于小猪。这不难理解，因为每一种哺乳动物都会产生专门针对自己物种的母乳。
Can cow’s milk really cause problems for my baby? Yes, very definitely. There have been literally thousands of papers written about the differences between cow’s milk and human milk, and how cow’s milk is not suitable for human babies. The good thing, of course, is that modern formula companies have made numerous attempts to make their cow’s milk-based formulas more compatible with the needs of human babies. They have done a great job but, frankly, nothing like human milk has ever been produced! Or to put it another way, no formula has ever been made that is exactly like human milk, no matter how much effort has been made.
And for my specialized area of calcium research, it was once quite a disaster to feed cow’s milk to human babies, because cow’s milk rapidly affected the babies’ calcium balance.
Isn’t it bizarre to think cow’s milk can cause babies to have seizures? Maybe it sounds bizarre, but it’s true. It happened when cow’s milk causes significant drops in the baby’s blood calcium levels, which then resulted in clinical seizures. Many babies suffered with seizures before this was understood.
It was discovered that the high phosphate content in cow’s milk was what caused the calcium drop. So formula companies which used cow’s milk (the majority of formulas) in their infant formulas changed the phosphate content, and the problem of low blood calcium was then markedly reduced.
However, just before my early retirement from academic research, we actually detected that there was still a significant stress on the calcium control system in infants receiving standard formulas, which still might be potentially problematic for the long term. From my viewpoint, this area still needs to be studied further.
What’s the strange relationship between milk and lactose? Indeed, lactose is one of those really strange sugars that we find naturally only in milk! You can’t find lactose in sugar cane, sugar beets, grapes or any other normal source of sugar! Nor essentially anywhere else in normal biology.
母乳和乳糖是什么样的奇怪关系? 乳糖确实是我们只能在母乳里发现的最奇特的一种糖！ 在任何其他正常的糖来源比如甘蔗，甜菜，葡萄中，都不含乳糖。甚至正常生物体的任何其他地方都找不到乳糖。
Furthermore, it’s also essentially the one and only carbohydrate or sugar in natural milk; there’s basically no other sugar at all in milk. These strange circumstances literally mean lactose must be doing something quite unique, but only in milk! After all, the word lactose is formed from Latin lac (“milk”) + -ose (“sugar”).
Have you been labeled as “lactase deficient”? Lactase is the enzyme which helps you digest lactose. In theory, if you’re labeled as “lactase deficient”, you can’t drink too much milk or eat a lot of dairy products. You probably know many people who have this label and take Lactaid (lactase) to “help digest the lactose” when they drink milk or eat dairy products like cheese.
You’re more normal than you think! Low lactase, however, is actually normal! Surprise! In reality, all mammals (animals that produce milk) always have very high levels of lactase in their gut during their baby period when milk intake is essential. High lactase therefore is present only when high milk and lactose intake is needed. Presumably a perfect fit in time and function.
The next phase in a baby’s life is weaning, meaning weaning the baby off breast milk. At weaning, surprise, in all mammals there is a dramatic drop in lactase, coincident with no longer needing milk or lactose, which again makes perfect sense.
Thus, in biologic reality, lactase is really only needed when milk is needed. So all adults really should have low lactase, as part of normal development!
But wait! Don’t we all need to drink cow’s milk!? Most westernized people think that everyone should drink milk. No, not really, and vast populations of the world do not drink milk or drink only a small amount of it. A high intake of milk after infancy often began when domesticated cows were extensively raised in Europe; the (usually) commercialized habit then spread around the world. Of course, there are also people who drink milk from camels, horses, goats, and yaks, but that’s another story.
Did you realize no other mammal normally drinks milk after weaning? Except for domesticated kittens, who obviously learned it from their bosses. If you didn’t know that before, now you do.
So who’s normal? Usually in population research, we say that the majority wins, so that if the majority of adults do not really have much lactase, we would have to conclude they are normal. So quit labeling yourself as lactase deficient! You’re not.
In history, all human babies normally have relied initially on only human milk to survive. That is self-evident. So it should be no surprise that in nutrition research, everyone considers human milk as the gold standard, when trying to determine any specific nutrition needed for babies. This still might beg the question of who set up this gold standard, and why it is really the standard.
And I think the answer is simply that It’s indeed a self-evident standard: in babies, what else would we really base the key nutrition standard on? Historically, without this gold-standard nutrition, the baby dies; that’s pretty dramatic, I would think. All over the world, over all generations. There can be other standards, but they’re just not gold.
我个人对母乳和配方奶的关注。在几十年的医学学术生涯中，我组建了一支由营养学的临床医生和科学家组成的科研团队，他们非常活跃，致力于钙和配方奶研究。因为早产儿的营养需求与足月婴儿完全不同，于是，我们感兴趣的一个领域正是系统性地优化营养和婴儿配方奶来喂养早产儿。正如我们的许多书籍 (1) 中所总结的那样，研究各种形式的奶是我一段非常有趣而迷人的人生时光。
Lazy conclusion. During my research years, I heard a brilliant, practically inspirational, lecture on the beauty of human milk. It included a “Star Wars presentation” of all the innumerable immune or defense factors that are present, and how the entire natural milk production system includes a complex system of protection (hence “Star Wars”) for the baby. At the end of the talk, the speaker poetically concluded how wonderful it was that evolution caused this to happen.
Afterwards, I went to talk to this lecturer and I asked him what his conclusion meant: did he really believe that breast milk “evolved”? He admitted that wasn’t what he meant; what he meant was, it was like a God mystery! I suggested, and he agreed, that maybe he shouldn’t use such lazy terms as “evolution” if he didn’t really believe it!
There’s no way that breast milk became better and better over millions of years. In fact, everyone should agree that there’s no logical way that human milk could actually evolve step-by-step from some “lower human” or other creature. All babies would have died waiting for it to happen!!
There’s just no way that human milk can produce thousands of different chemicals or nutrients step-by-step through millions and millions of years. It’s clearly one of those all-or-none things in life. You either have the whole perfect human milk, or the baby will die. You can’t have any partially complete milk! Nor partial death scenarios either.
It’s as impossible as the theorized/fantasized pathetic efforts of a rat pup sucking vigorously on its mother’s sweat glands, generation after generation, in order to hope to produce a mammary gland! It’s really boils down simply to “Give me milk or give me death!” There has to be a better way.
A beautiful design. All natural milks are complexly designed and totally functional. They are really a perfect design. And human milk is made specially and specifically for human babies, which is perfectly logical. Precise, simple and correct. And billions of babies appreciate that. Including you, once upon a time.
- Tsang, RC; Uauy, R; Koletzko, B; Zlotkin, S; (2005) Nutrition of the Preterm Infant: Scientific Basis and Practical Guidelines.Digital Educational Publishing.Inc
Nutrition During Infancy: Principles and Practice 第2版, 2009, 原著 Reginald C. Tsang, Stanley H. Zlotkin, James W. Hansen, Buford L.Nichols 主译李廷玉; 副主译:李继斌, 魏小平: 译者: 李廷玉,李继斌, 陈立, 唐芳,魏小平, 赵勇, 练雪梅, 陈科, 宋萃, 张萱, 王丽, 荀泽丽, 人民卫生出版社, People’s Medical Publishing House.