Lactase persistence
I want to milk out an episode about milk.
Lactose intolerance is on my mind lately as I seem to be experiencing a bout of it. Yes, lactose intolerance can, apparently, be intermittent. It comes and goes in some people, and let me tell you, it has come for me, bloating and abdominal cramping and gas and diarrhea even from just a little ice cream. I know I shouldn't be eating it, but have you tried these Nightingale. Ice Cream Sandwiches? Nightingale is this originally mom-and-pop operation out of. Richmond, Virginia. They make these giant gold bar-shaped ice cream sandwiches.
They come in this brown paper bag packaging. I get them at the grocery chain Fresh Market. They're apparently available nationwide in the United States. The cookies are super thick and they're really chewy. It seems like what they do is they bake giant sheets of cookie and then they cut rectangles out of that sheet, which of course would be a very efficient production process, and it results in cookie rectangles of totally uniform thickness all the way across. They do not taper down at the edges the way a conventional cookie would. I really like that even thickness for some reason. I don't know, I just do.
The ice cream layer is preposterously thick. I can eat them by just opening my mouth real wide, but I feel like I'm going to dislocate my jaw at some point doing that, so I usually use a little knife to cut little bites off of the sandwich, and for whatever reason, I enjoy those little bites a whole lot more. The double, or I guess it's the triple chocolate flavor is my favorite, but there's also a blondie flavor that is insane. Get yourself a Nightingale Ice Cream Sandwich if you can find one. They have a line of mini sandwiches called CHOMPS. You get a CHOMP. That's apparently at Walmart now, at least in some places. Not an ad, just a fan.
Anyway, just one little CHOMP of those is enough to completely ruin my night at the moment because I am going through a majorly lactose intolerant phase, which much of the rest of the world might refer to as adulthood. The pathologization of lactose intolerance is one of the classic examples of Eurocentric bias in science and medicine, also the bias of the agro-industrial regulatory complex. The dairy industry is very powerful in the United States and in US government. If people exhibit a biological trait that makes the dairy industry's products undesirable to them, well, the industry will definitely want to classify that trait as a sickness needing to be cured. But, most people on this earth are lactose intolerant, or at least they are milk intolerant in some way. Most mammals on this earth, not just us, most mammals on this earth are milk intolerant when they become adults. Milk intolerance is just the normal state of being for a grownup mammal. One of the defining traits of the mammalian class of animals is our sweat glands that we use to maintain a constant body temperature.
That's one of the things that mammals have as opposed to cold blooded animals. Some evolutionary biologists argue that mammary glands evolved from sweat glands. Others think they evolved from sebaceous glands, which are the ones in your hair follicles that make the oil in your hair and on your skin.
But regardless, mammals have mammary glands that make milk.
It has been speculated that milk might have first evolved as a means of keeping eggs moist when they're outside of the body. Bird eggs are highly mineralized, hard, coated in a mucus like sealant, and thus they can retain moisture. Thus, birds can lay their eggs pretty much anywhere and they won't immediately desiccate. Amphibians, in contrast, lay these soft little eggs that have to stay underwater, otherwise they dry out in a flash.
Reptiles lay eggs somewhere in the middle. They lay soft leathery eggs that can survive on land, but reptile eggs generally need to be kept somewhat moist. Mammals evolved from reptiles some 225 million years ago, and our production of a specialized sweat or oil called milk may have originally been something that we did to keep our eggs wet. It's easy to imagine how gradually the babies would start drinking that milk directly upon hatching, and that would be very evolutionarily advantageous. Neither mother nor baby would have to leave the safety of the nest in order to go and find food. She has the food in her body already. She was able to gather that food simply by eating and accumulating body fat long before she ever even laid her eggs. In early mammals, the phase in which the babies incubate in eggs outside of the mother's body, that got shorter and shorter and shorter until eventually the eggs started hatching inside the mother's body, and thus, live birth evolved.
All mammals do it except for a few weirdos in Austral-Asia like the platypuses, they still lay eggs, but literally all mammals still nourish their young with milk. All milk contains simple carbohydrates, i.e., sugars, because that is the main basic fuel that animals burn for energy. The primary simple sugar to be found in almost all mammalian milk is lactose, which is a disaccharide like table sugar. It's two sugars bonded together. But whereas a sucrose is a glucose unit and a fructose unit stuck together, lactose is glucose and galactose. Us humans make a ton of lactose in our milk. Our milk is about 7% lactose by weight. Cows milk is about 5% lactose.
Goat's milk is a little lower, maybe 4%. Some people who can't tolerate cow's milk say that they can tolerate goat's milk. Maybe that's due to the slightly lower lactose content, but it could also have to do with the protein content of the milk. Different beta-caseins in goat's milk compared to cow's milk, if you look at it. Scientists have implicated this particular kind, A1 beta-casein, as a digestive irritant in some people. We digest it into the peptide beta-casomorphin-7, which can cause intestinal inflammation and therefore mal-absorption. So what people think is lactose intolerance might actually be cow's milk intolerance specifically, because cow's milk tends to have a lot of A1 beta-casein. For all I know, I'm not lactose intolerant at all.
I might just be another kind of milk intolerant. This milk protein intolerance phenomenon is something that needs more research according to the authors of the scholarly book chapter that I am chiefly referencing for this entire episode, which is Nutrition in the Preservation and Treatment of Disease, fourth edition, chapter 40, Nutrient Considerations in Lactose Intolerance by a whole bunch of scientists at Purdue University here in the United States, one scientist at Trinity College in Ireland, where lactose intolerance is virtually unheard of, and we will get back to Ireland.
Also, there's one author on this chapter from Abbott Laboratories, which is the company that makes all kinds of dairy-based meal replacements and supplements like Ensure. So not surprisingly, this chapter very much pathologizes milk intolerance, because anything bad for business must be a disease, right? So take that for what it's worth. But I have no reason to doubt the underlying basic science here that is distinct from the policy or treatment prescriptions that one might derive from the basic science.
The basic science tells us that lactose
Cannot be absorbed by the lining of our small intestines.
Not my intestines, not your intestines, nobody's
Intestines can absorb lactose.
Neither can sucrose be absorbed in the small intestine.
To digest sucrose, table sugar, your body has to make an enzyme called sucrase that breaks the bond between the glucose and the fructose. And some people can't do that. Sucrose intolerance is also a thing, though much rarer than lactose intolerance. To digest lactose from mother's milk, animals like us must produce an enzyme called lactase, most of which in humans is created by cells on the interior surface of the jejunum, which is the second stretch of the small intestine. The most serious kind of lactose intolerance in humans is congenital lactose intolerance in babies, babies with genetic mutations that either cause their body to make no lactase enzyme at all or the activity of that enzyme is in some way inhibited. Prior to modern medicine, severe congenital lactose intolerance would've been a death sentence for any baby. If mother's milk is the only food available to you and you can't digest the carbs from that milk, you're dead. If your mother and the other adults around her understand what's happening on some level to you, they get that the mother's milk is messing with your system, they maybe try to feed you some other kind of liquid food.
And even if you're able to digest that, it probably won't have all of the other nutrients that you need for early development. Milk is the perfect food for early developments. That's why it evolved as such. Whatever you're eating instead probably doesn't have all of the essential nutrients that you need for your stages of development, and then you're dead. Congenital lactose intolerance in infants is therefore very rare because most people with that mutation would not have survived to pass it on to the next generation. Finland is an outlier here, as it is in so many ways. The Finns are a historically isolated group of people, and so they have a bunch of unique linguistic and genetic features, one of which is a predisposition toward congenital lactase deficiency. But even then, only 42 cases were documented in all of Finland between 1966 and 1998.
Congenital lactase deficiency in infants, only 42 cases in the whole country across all those decades. It's just an incredibly rare problem, because historically, almost no one could survive it. You can survive it now if you're born into a good healthcare system, so we'll see what that does to our evolution over time. But the point is, most human and other mammalian babies are able to make the lactase enzyme they need to digest milk sugars because they simply have to. Of course, all of us mammals gradually start eating other foods as we develop, as we grow teeth, as our jaws and our tongues and our throats all get stronger, as we build up a microbiome capable of helping us digest our food in our guts. We gradually start eating food from our environment instead of just food from our mothers, and this is a process called weaning. Most mammals stop producing lactase enzyme after weaning because they just don't need it anymore. The gene for making lactase stops expressing itself probably as a result of DNA methylation.
This is the process by which methyl groups bond to DNA molecules as we age, and this has the basic effect of turning genes off. That was a profane oversimplification, I'm sure. But anyway, most adult mammals, including most adult humans, make little, if any, lactase, because there was just no evolutionary advantage in making lactase through adulthood. Until about 10,000 years ago or potentially much earlier than that. But about 10,000 years ago is when domestication of animals really took off. The wolf was probably the first one, resulting in dogs, but that was probably a distinct phenomenon from the animals that we domesticated primarily as food sources, the first of which was probably the goat or maybe the sheep, maybe both. This is a process that proceeded independently in many different places, but goats and sheep and cattle and pigs were all domesticated in West Asia 10 or 11,000 years ago. And if you need food and you see baby goats suckling on their mother's tits, well, necessity is the mother of invention.
And eventually you discover that a mother mammal will keep producing milk as long as she is regularly milked.
Once she gives birth, her milk production
Is switched on, and it generally won't switch off as long as something yanks on her nipple a couple of times a day and relieves the pressure inside her mammary glands, thus signaling those glands to produce more milk.
Goats and sheep and cattle are all excellent dairy animals. Pigs not so much. Perhaps because they are smart enough to know what you're doing to them and they do not like it, or maybe they're just really aggressive, maybe both. Milking a pig is a dangerous proposition, apparently. I've never tried it, I've just read. But cattle can sit there and take it.
In fact, they like being milked as long as you do it gently. Milking cattle or sheep or goats was a phenomenal way for humans to get food in rough climates, arid climates, where nothing grows but grass, and humans cannot digest grass. We can digest the seeds, which is what wheat and rice are, but we can't digest the bulk of the grass plant. Cows can, and they convert that grass into milk. Animal milk was also a terrific source of food in cold climates where lots of food may grow in the warm months but nothing grows in the winter and you got to eat something. Of course, the cows might actually stop lactating in the winter if they're really stressed from cold or lack of grass to eat, but that's fine because you made cheese. Cheese and other fermented dairy products are the primary means by which humans have preserved milk. And here's the thing about lactose, it is highly water soluble.
So when you introduce acid into milk or you introduce the rennet enzyme from ruminant animal stomachs into milk, you curdle the milk. You denature the casein proteins, you open them up, you reveal bonding sites that tangle up and bond with each other. And the casein proteins form clumps that we call curds, and these curds also contain lots of the fat in the milk because casein is an emulsifier and it sticks to the milk fat. So you strain these curds out of what is left of the liquid milk, and these curds contain very little lactose. The lactose is water soluble, so it's in the water phase of the milk that you just left behind that we call whey. The trace amounts of lactose in the curds might not even be enough to upset your adult bowels, but if it is, you've got another tool at your disposal which is fermentation. You pack up those curds and you hold them in favorable conditions where they will not rot, but bacteria and fungi can eat the lactose, converting it into tasty, tasty metabolites like lactic acid, resulting in a ripened cheese that tastes delicious and contains basically zero lactose. Or maybe you didn't make cheese, maybe you made yogurt, where you didn't separate the curds and the whey.
You just let lactic acid-producing bacteria munch on your milk for a while, and they convert a lot of the lactose into lactic acid, and that lactic acid in turn coagulates the casein proteins giving you a more solid texture, and that's yogurt. Regardless, fermentation of milk, which people probably thought they were doing just for preservation purposes, that also rendered the milk less digestively irritating to adult humans whose bodies made little, if any, lactase enzyme. But something funny happened among certain populations of humans, a relatively recent evolutionary adaptation starting around 10,000 years ago, they think. Some of us evolved to keep making lactase into adulthood. This is a phenomenon known as lactase persistence. Some people argue that lactase persistence is really the proper term to describe this phenomenon, this phenomenon where some adults can digest lactose and most other adults can't. In the West, we usually refer to that phenomenon as lactose intolerance, but globally, lactose intolerance is the norm. That's normal human, biological state of being right there.
Lactase persistence is the weird thing, that's the aberration. And therefore, it's probably more logical for us to describe this phenomenon as lactase persistence. Lactase persistence seems to have evolved independently in a few different human populations, so totally different trees of evolution.
In East Africa, for example, lactase persistence
Seems to have evolved among pastoralist societies in what is now sudan, an arid environment where you need animals to convert grass into food for you.
Southern Sudan at least.
But the same gene did not pop up much at all in West Africa, where they had a lot more food options. And thus, the ancestors of most of the contemporary African-American population are who they are, which is 80% lactose intolerant. Some 20 or 25% of modern Black Americans can handle lactose, but most of them cannot because most of the contemporary African American population are descended from people abducted from West Africa, and West Africa had lots of different food options available to them, they didn't have to evolve to be reliant upon milk.
Lactase persistence seems to have evolved independently in Central Asia, so that's a totally different thing. Easy to imagine how adults with a random mutation, allowing them to derive all of the energy from unfermented animal milk, they would simply have had more food available to them in those relatively infertile grasslands of Central Asia. And they could have, therefore, out-competed other groups who did not have that mutation. Maybe a third of modern Kazakhs are lactase persistent despite the fact that they have very little European genetics in them at all. So scientists think that it evolved independently there, and it might explain why some contemporary residents of Northern India are lactase persistent. That might have been the Arians coming down from the Pontic steppe and spreading their lactase persistence genes along with their Indo-European languages. There's a big pocket of lactase persistence in Arabia. Another independent evolution they think.
Arabs are thought to have co-evolved this along with their domestication of the Arabian camel. Another harsh environment where there's not a lot of food options around, so camel milk. But if you look at a heat map of lactase persistence in today's world, your eye will go immediately to Northern Europe because that is easily the global center of this phenomenon. Northern Europe is where the highest proportion of people evolved lactase persistence by far. Northern Europe, not Southern Europe. The Romans wrote about this. They were amazed when they went up to conquer ancient Germanic and. Brittonic peoples, and they found adults among these tribes drinking milk, unprocessed milk.
Of course, the Romans had cheese and yogurt, they loved that, because lactose in cheese and milk has been mostly fermented into other stuff. But adults in Rome generally did not drink milk, relatively unprocessed dairy products, because that would make them blow. Then all of a sudden, the Romans encountered these Germanic barbarians charging at them with their battle axes and notably not blowing despite the fact that they had carved up for the battle on milk. My intermittent lactase persistence could therefore be seen as a continuation of that battle. Anyway, Northern Europe is the global genetic epicenter of lactase persistence. Lactase persistence evolved independently all over the place, but nowhere did it spread as uniformly as it did in Northern Europe. That lactase persistence rate in Ireland is virtually 100%. If you're Irish and you can't handle dairy, that probably means your family has not been Irish for very long. Why that lactase persistence is so much more advantageous to Northern Europeans is a very interesting question. Why did lactase persistence survive and thrive while basically all of the other Northern European populations either died off or migrated elsewhere as evidenced by the fact that everyone in Northern Europe is lactase persistent? Well, as we said, Northern Europe is cold and can be rather harsh. You can't farm there all year round the way you can in say, South and Central East Asia, where almost no one is lactase persistent.
Who needs milk when you can grow three distinct crops of rice every year? Asians today are generally only able to enjoy relatively unprocessed dairy with some significant pharmaceutical assistance, which we will get to. So yeah, if you live somewhere cold, it's very useful to have an animal that converts grass into milk for you. But it's not just cold in Northern Europe, it's not just cold, it is also dark. If you don't live in Northern Europe, it's easy to forget how damn dark it is there. My beloved agent, Colin "The Best" West, was here visiting me down in Tennessee recently, and we were talking about his boyhood in Scotland. He remembers getting out of school at three o'clock in the afternoon, and in the winter, it would be dark outside already. He would walk home from school in the inky blackness. That's a depressing way of life that I associate with subarctic living.
That's that's the Bjork lifestyle. Icelanders, Alaskans, Siberians, they're the ones I imagine living half the year in inky blackness, but the Anglo Celtic Isles are pretty much just as far north. Even Spain, freaking northern Spain is on the same latitude as Nova Scotia over here in the Americas in Canada. Why don't we think of Scotland as being part of the subarctic, which it is strictly in terms of latitude? Well, it's because the oceans are running AMOC, A-M-O-C, Atlantic Meridional. Overturning Circulation, A-M-O-C, AMOC or AMOC, ocean currents that push warm surface water from the Southern Atlantic up northward while they pull deep water, cold water southward. The surface ocean water around Northern Europe came from down south, so it's warm. So it warms the air above the ocean, warm air takes up more space than cold air, so it pushes against the cold air that's hovering over the land. The warm air pushes off of the ocean and onto the beach and into the land, and that's what a sea breeze is.
The sea breeze in Northern Europe is warm because of AMOC.
Thus, Northern Europe is relatively warm despite
Being ridiculously far north.
It should be said that climate scientists
Are really worried about amoc, those ocean currents that make northern europe warm.
This is one of the reasons why they try to refer to global warming as climate change, because yes, the overall trend is a warming trend, but overall warming can and does and will result in local cooling effects in some places. The models show global warming weakening this flow of warm atlantic water to Northern Europe to the point where it could collapse irreversibly, at which point London would end up being just as cold as Winnipeg, a frigid Canadian city on the same exact latitude 50 degrees north. I remember as a kid in school wondering why British colonization of the Americas really took roots so far north in freezing cold New England in Canada, like, "Why did they go there? If you could sail to any part of this beautiful continent, why would you settle there?" The answer is because it's the part of the continent that was directly across the water from Britain.
It's just colder than Britain because AMOC. Anyway, point is it's dark in Northern Europe.
It's darker than it is cold, in a sense. And where people don't get enough sunlight, they don't get enough vitamin D. Your body sends a derivative of cholesterol to your skin where it can be exposed to UV radiation from the sun, thus transforming it into vitamin D3. Vitamin D is required for the transport of calcium around your body. And so, if you don't have enough vitamin D, your cells don't get enough of the calcium that they need for all kinds of vital functions. Therefore, if you lived somewhere dark and were, therefore, vitamin D deficient, it would've been advantageous to eat lactose because lactose enhances intestinal absorption of calcium. This is, by the way, why milk is often artificially fortified with vitamin D, because vitamin D and lactose and calcium all work in concert to keep you from getting diseases like rickets, osteoporosis in older people. Anyway, this is one hypothesis as to why a lifelong ability to digest milk would've been particularly advantageous to people in Northern Europe.
Though the particular lactase persistence genes found in Northern Europe might not have originally evolved in Northern Europe, some studies indicate these mutations first emerged in the Balkans and Central Europe some 7,500 years ago with what is known as the Linear Pottery culture. That's where the song was written, but the song really became a hit a little further north, where almost everyone today is lactase persistent, at least everybody up there in Northern Europe who is descended from people who have lived in Northern Europe for a very long time. Northern Germany, Northern France, Scandinavia, Britain, and Ireland, people with deep ancestral roots in those places can generally handle dairy just fine. And therefore, people like me living in places colonized by Northern Europeans can also generally handle dairy just fine. Western medical science has historically been dominated by people of Northern European descent. Therefore, it is naturally reflected Northern European cultural biases, one of which is the notion that lifelong milk drinking is the norm and everything else is a pathology, a problem that needs to be fixed. Instead, it seems as though the opposite is true. Most people on this planet are not lactase persistent because the majority of people on this planet are Asians.
We've talked about this before, how more than half of all of the people alive right now live in East and South Asia, and how this may be attributable to rice, the perfect crop. As we said, some people in northern India, Pakistan, Iran and such, they have the genes for lactase persistence, perhaps because of their Arian heritage. But nobody on the rest of South and East Asia is lactase persistent, and nobody in pre-Columbian America was lactase persistent. Why are basically all indigenous Americans lactose intolerant? Well, maybe it's because their ancestors came from East Asia, they crossed the land bridge between Siberia and Alaska, and they came down. They also didn't have any milk animals with them with a notable exception of alpacas. Alpaca milk is absolutely a thing today. Among modern Hispanic people, maybe a third are lactase persistent, but that seems to be the influence of European genetics. Because in Southern and Central America, European colonists blended much more with the indigenous population.
In northern America, we mostly just killed the indigenous population. I don't seem to have much, if any, indigenous American genes in me. I have a Northern European side and a Southern European side battling each other in an eternal recreation of the opening scene from Gladiator where the Romans are fighting some Gaulic tribe. At the moment, it seems as though my Roman half, my Southern Italian half is winning, because if I eat so much as a CHOMP, that is the mini version of the exquisite Nightingale Ice Cream Sandwiches from Richmond, Virginia, if I eat so much as a CHOMP, I and the people around me are in for an unpleasant day.
What happens when a lactose intolerant person eats a bunch of lactose? Well, it depends, because as we mentioned, there are several distinct kinds of lactose intolerance identified by medical science as distinct pathologies.
Should we regard them as pathologies considering
That lactose intolerance is globally normal and natural? well, i reckon the more enlightened way to define a pathology is on the individual level and not on the population level.
If anything happens inside you that you don't like and you would change if you could, well, that's a pathology. It's a pathology if you think it is.
I would like to be able to eat those ice cream sandwiches, therefore, I choose to view my lactose intolerance as a pathology. But that certainly doesn't mean you have to. You can just accept yourself for who you are. That's probably better and healthier, assuming you have ample access to non-milk foods, which you probably do. But I consider it a pathology within my own body, and I have no idea which particular kind of lactose intolerance I intermittently have. There are tests you can do such as the hydrogen breath test. If you either don't make the lactase enzyme or if your lactase activities in some way inhibited, the lactose will pass to your large intestine where the bacteria there will absolutely have no trouble digesting it at all. They will ferment the lactose, producing various waste products, including hydrogen and methane.
This can be detected by a device on your breath. It can also be detected by everyone in the room around you as you blow ass all day. Here's another delightful factoid from the body building subculture that I'm weirdly obsessed with, protein farts. Protein farts, that's a thing. Remember like a half hour ago we talked about how lactose is water soluble, and therefore when you make cheese, most of the lactose stays behind in the whey. Well, some of that whey is processed into protein supplements chugged by gym bros. And even if said, gym bro is a northern European, even if it's Marcus Ruhl, your body can only make so much lactase to break down the lactose into its constituent glucose and galactose units for absorption into your bloodstream from your small intestine. At least some of that lactose is going to pass intact into your large intestine where microorganisms will eat it and produce gas.
And thus, some of the vainest people in the world, people who spend most of their waking hours working on their appearance, some of those people also smell terrible because they have protein farts, or they used to, or they used to. Protein supplement makers are wise to this, and they've been working on this problem for some time, developing evermore efficient ways of isolating the whey protein from the lactose and all the other trace components. This also lowers the calories of the supplement, and that might make it more desirable to some consumers. Also, at some point, the whey protein industry got wise and just started putting lactase enzymes directly into the powder. I look at your protein powder. Most of the ones that I see on the market these days have lactase listed in the ingredients, assuming it's a whey protein. There's plant-based protein powders that wouldn't need that, but for milk-based protein powders, yeah, they're just putting lactase straight into the powder nowadays. Lactase can be synthesized via industrial fermentation, and you can just put it in the protein powder.
And so that when I drink that powder, yes, I'm taking in lactose, but I'm simultaneously taking in the lactase that will break down the lactose as it all mingles in my system. And of course, you can just put that lactase enzyme that you made with industrial fermentation, you could just take that and put it in a pill that you swallow with any other dairy food that you might want to eat such as Nightingale Ice Cream Sandwiches. #notanadjustafan. Lactase supplements are proven to be pretty effective in most people as long as you take them at the right time, which is with your meal or 15 minutes at most before your meal, and if you take enough of the supplementary lactase. You just have to remember to take it, and you have to take enough of it. I usually need a lot, and I don't remember to take it. Some people, however, are not helped at all by lactase enzymes.
One study found about 18% of the
Subjects who said that they were lactose intolerant experienced no improvement at all in their symptoms when they took the lactase supplements with their dairy foods.
They were measuring it not just subjectively
By the painful and unpleasant symptoms experienced by those people, but they were also doing breath tests and stuff, and in like 20% of those people, they got no benefit at all from the lactase supplement.
One potential explanation for this is that lactose intolerance is about more than just lactase. It's also about your microbiome, the community of organisms in your gut that eat your food with you. This is not as super well-understood by scientists yet, but there have been studies done on probiotics where they give people supplements designed to feed the microbiome, and those people end up digesting dairy better in time after they've been taking those supplements for a while. The causes for that could be enumerable. Maybe one bacteria is eating the lactose but another bacteria is eating the waste products produced by the first bacteria, and thus your ass blowage stays at normal levels. I should specify that this is more important than just farts. Some people are so aggravated by lactose in their intestinal system that the lining swells up, and this interferes with the absorption of other nutrients, and people can get really sick if they are constantly eating lactose that their body can't handle.
But anyways, lactose problems might actually be gut health problems in some people rather than lactase-producing problems. Maybe my lactase-producing gene isn't turning on and off the way I assumed that it was. Maybe my problem is intermittent because of changes in my gut microbiome and/or changes in my diet. Lactose intolerance has been shown to be affected by the foods that you eat with the lactose. Maybe I just haven't been getting enough soluble fiber lately. Soluble fiber slows gastrointestinal transit, which gives lactase in your small intestine more time to bump up against the lactose and break it down. There are studies showing that a high fiber diet can improve lactose intolerance symptoms. Fat can also improve those symptoms, a higher fat diet.
Studies show that whole milk bothers people a little less than skim milk, and that may be fat slowing gastric emptying and allowing the lactose more time to break everything down. The lactase rather, allowing the lactase more time to break everything down. There are, of course, modern milk products designed specifically for lactose intolerant people and other milk intolerant people, so milk with lactase enzymes that are in it. Or there's also milk that's inoculated with these particular bacteria that can metabolize the lactose. Or actually, I think it's more complicated than that, but many options are available to the lactose intolerant these days, or the otherwise milk intolerant these days should you consider your lactose intolerance to be a pathology, which is between you and your God. My God at the moment is Nightingale Ice Cream Sandwiches, so. I'm going to take my lactide and I'm going to take my probiotic and see if I can't remedy the situation for myself and for my loved ones who must share a house with me. Of course, another option is to just eat the dairy products and not worry about the symptoms.
Lactose intolerance is a minor discomfort in most people, and you can simply live with it as people in Tibet seem to have done for generations. The Tibetan Plateau is a very harsh environment for human habitation, not a lot grows there, so animal foods are king. Plus, the calorie needs of a person living at that elevation are enormous, so fatty dairy products are a historical necessity on the Tibetan Plateau. My wife, Lauren, and I had our first two dates at the two Tibetan restaurants that were in. Bloomington, Indiana at the time. Date number one was at Snow Lion, which isn't there anymore, and it was not a particularly successful date. Date number two was at Little Tibet, which is still there, and so is our marriage, because that was a more successful date. You should go to Little Tibet on Fourth Street in Bloomington, Indiana if you live anywhere nearby, fantastic place.
There's a whole Little Tibetan diaspora in Bloomington that I believe formed around a brother of the Dalai Lama who was a professor at Indiana University, the brother. Anyway, I remember reading a newspaper article where the chef at one of those Tibetan restaurants in Bloomington said something to the effect of, "The food we serve isn't really Tibetan food, because real Tibetan food is so insanely high in butter fat that no one here would even be able to digest it." The calorie needs of a person at high elevation are way, way higher.
Hence, Tibetan butter tea and all of the other extremely high dairy fat delights that those of us at normal elevation probably have absolutely no business eating.
You would think that people living in
Such a dairy dependent society would have all of the genes for lactase persistence.
But no, only about a third of Tibetans seem to have those genes. The rest simply do without. And they've done just fine on an extremely dairy heavy diet from many generations. Perhaps because their microbiomes have built up to handle all of the lactose that they cannot digest themselves.
It passes to their lower intestine, and they've got a microbiome that can metabolize that lactose into maybe some short chain fatty acids that are great for their health in other ways. I don't know, but it works for them.