This blog is about the intersection between evolutionary biology and food. But also about practical applications, sustainable agriculture, and general tasty things.
When I was in high school and college I struggled with insomnia. The worst was when I lived in the dorms. Snoring roommate I hardly knew five feet away from me, sodium lamp light streaming in through the blinds, the ever-constant noise of slamming doors and drunken college students. I was constantly sick, constantly tired, almost always teetering on clinical depression. I missed class constantly, only getting by because like most colleges, the classes were a colossal waste of time and I could pass the tests just be reading the books. Recently when I was telling someone that the college I attended later in Europe didn't have such factory-farm-like housing and I did better health-wise there, someone said "well, dorm-living is a rite of passage." I kind of wanted to tell them off, tell them about how miserable I was and how it kept me from doing my best, but I guess some people are lucky and are able to endure it better. But the fact that the next door clinic was always full of legions of the chronically sick and the psychologists were constantly booked told me otherwise.
I tried everything to get to sleep. I even built some hybrid ear-plug/headphones and tried all manner of podcasts, classical music, even insipid "whale singing" and "relaxing sea sounds." I tried sleep masks, I even tried using Benadryl. Every night I lay there for hours past midnight before I could fall asleep.
When I studied in Uppsala things started to get much better for me. My room was so comfortable and noise-isolated there, it got much easier to fall asleep. I still had some occasional trouble though. The main trouble since then seemed to become distraction. It was just so easy to watch "just one more" episode of whatever show I was into on my laptop. Or play "just one more" hour of video games. "Just one more" often became a lot more. And I would often fall asleep under the glimmering light out of pure exhaustion well past midnight. Up until two months ago, it was really bad because I was in a studio apartment, my Macbook light tempting me all night, my video games stored under my bed in easy reach (I purposely buy simpler games out of the delusion I won't get addicted, but it doesn't always work out). At some point I was playing video games AND watching Netflix at two AM, a perfect storm of over-stimuli. My smart phone sat charging on my nightstand. I realized that I was "sleep walking" or something at night, checking my email at 4 AM without even realizing it and waking up to an inbox full of mostly already "read" messages. I was like "this has got to stop."
Luckily I moved into an apartment with multiple rooms of my own, something I've never had. I took my bedroom and made a rule that there would be no electronic devices in there besides a lamp, a radio, and the old un-backlit kindle. The windows are covered with blackout curtains. My phone charges in the kitchen. I go there at at 11 or midnight, start to read, and fall asleep easily.
Now that it is winter, I've also programmed my thermostat to drop to 45 F at night, extra motivation to go to bed. It reminds me of staying in a log cabin in the woods, heated by wood, and at night it gradually gets colder as the fire dies. And you are virtually forced to wake up naturally in the morning to put more wood in.
I've also been experimenting with daytime temperature. I keep it at 50 F when I'm away, but 61 F when I'm there. But I'm wondering if I could gradually go lower and adapt to it. I don't hope to match the achievements of legendary Cold House Journal folks, but I admire their fortitude and thrift. They make me feel rather weak.
Unfortunately I sometimes work in an office where my co-workers like to keep it at 75 F (WTF). When we walk to lunch, some of them look like they are about to die from the cold, even though it's hardly even cold for Chicago yet. I have to wonder if just not getting used to colder temperatures makes them less likely to be active.
A walk in the woods
I walk 20 minutes to work and I'm too stubborn to stop in the winter, particularly after living in Sweden where I saw people bike and walk everywhere even in the deepest dark winter (dark as in you need lights for your bike at 1 PM), so I can't afford to not be cold adapted. It is interesting that in the past I've really struggled with winter. I grew up in Georgia and I used to think I wasn't cut out for the winter because of it. My mother always kept our house pretty cold. I had to sleep under two comforters and an electric blanket. I blamed cold on being sick all the time. In retrospect, I wonder if the low-fat and later vegetarian and vegan diets were why I was constantly miserably cold all the time. The worst was when I was a raw vegan. I felt like I was never warm in the winter, even when I turned up the thermostat as far as it would go. Now these days, fueled by a good hearty beef stew, I feel able to easily endure the winter chill.
It also doesn't surprise me at all the researchers have tied indoor heating to obesity. "Good fat" known as brown fat, which burns calories, is activated by cold. People tend to gain weight these days on traditional rich holiday foods, but maybe they wouldn't if they paired them with traditional cold temperatures.
I'll never forget looking at my window in Sweden and seeing dozens little preschoolers playing in the snowy woods. They play outside every day. No matter what the weather. Here I walk by the local school on my way to work. The playgrounds and ball fields are eerily and starkly empty.
A few years ago, when I was in college, I was on a volunteer trip in the North of Wisconsin and I was invited to an Ojibwe sweatlodge. I had never had an experience like that before. It was incredibly powerful, like being reborn inside a volcano. But it also tested the very limits of my heat endurance, particularly since Christian missionaries influenced the tribe enough that women have to wear thick long skirts while men go into the lodge shirtless. I never did a sweat lodge again, but when I moved to Sweden I discovered sauna culture, which has many of the same benefits, but is usually much more casual and less extreme (except for a few stupid isolated incidences like the guy last year who died in a "sauna contest."). In Scandinavia saunas are often paired with swimming in cold water, which is probably why that region, along with Russia (which has a Banya culture), produces some of the world's top cold-water swimmers (many of whom are women, who have an advantage thanks to higher body fat). I'll write more about that later, particularly since I hope to interview some swimmers when I go to Stockholm next month. I'm also planning to write some more on sauna and the studies done on that subject. Fire adaptation isn't just a joke.
But lately I've thought of sweat lodges because of the whole "cold adaptation" thing that's caught on a bit. Richard Nikoley posted a pro-Dr. Kruse anti-intellectual screed. The gist of it seemed to be: well, I benefited from cold water, so Dr. Kruse must be onto something and I like him anyway. Ok. Dr. Kurt Harris and Dr. Emily Deans tried to talk some sense into him. Thankfully Ray Cronise, who happens to be an expert on the subject, showed up and finally Nikoley listened to a voice of reason. If you are interested in doing some thermal hacking with cold, I strongly recommend that you follow Ray's sane science-based recommendations.
Water temperature less than 60F/15.5C and air temperature less than 32F/0C are great lines of WARNING. in temperatures lower than this there is a chance of hypothermia. Walking hypothermia* can be very serious (google it) and so it stands to reason when you go below these thresholds it’s 1) at your own risk and 2) should be done with caution.
Contrast that with Dr. Kruse's recommendations, which involve ice water and he dismisses the significance of numbness, saying "My entire torso has been numb for 8 months now." Yikes.
Sweat lodges were touted for similar health-related benefits, as well as used for quasi-Native American new age rituals, often to the chagrin of actual Native American tribes. Unfortunately, in 2009 several people died in a New Age sweat lodge ceremony. The Lakota Nation filed a lawsuit against the guru responsible for the faux-sweat lodge ceremony that pushed so many people into the danger zone. The Lakota were concerned about their traditions being used irresponsibly.
Either way, you'd all have more fun and probably get more benefits by heading to your local Banya or Korean sauna and doing a normal sauna session and then a dip in the cold pool. Maybe have some good offal-rich soup that most of those traditional sauna places serve. When I lived in NYC I often went to Coney Island Banya, but I've heard good things about Castle Spa, a Korean place in Flushing. However, none can compare to the Finnish saunas. Nothing like a sauna next to a ice-filled lake. And grilling some sausages on the coals. And total co-ed nudity (actually less sexy than you would imagine). Or the Austrian sauna I went to in the mountains where we ran outside into the snow.
Sauna + cold pool = fun
Numbness = bad, and not fun
I find that the more regularly I do sauna, the better I am at dealing with cold. And that's important, since I don't drive and I've lived in cold climates for the past decade. And I like wearing miniskirts even in the dead of the Chicago winter. And being able to forget my gloves. I wasn't always this way. When I first moved from Georgia to Illinois I remember having to sleep under two comforters and an electric blanket.
And the Game of Thrones scene that I always think of when I read people from the South talking about cold adaptation:
* you might want to look up afterdrop too. Also I find it interesting that other neurosurgeons have done controversial cold therapy.
In my last post, I wrote about how it's impossible for epigenetic changes from very cold environments 3-4 billion years ago to have been conserved. Somehow people thought I was accusing Dr. Kruse of making up cold-adapted monkey ancestors or something.
No, I realize he doesn't mention cold-adapted monkeys, but he also doesn't stick to bacteria living in sad cold slurries either. He also mentions ancient mammals. Dr. Kruse also has an interesting belief that all mammals “evolved in the polar environments on earth.”
I can't find any evidence that early eutherian mammals evolved in such an environment or even a later candidate for a polar eutherian that could be a possible ancestor. They discovered the earliest known (so far) eutherian fossil last year in China, Juramaia sinensis, in a Late Jurassic formation. The climate in the area at the time was relatively warm and dry. Juramaia sinensis' teeth suggests it was an insectivore. Many other early mammal fossils have been found in Asia, but as we know, mammals went on to colonize a variety of environments and climates.
Dr. Kruse says "mammals were ideally adapted for hibernation too, until they got too smart for their own genes sake.” It is indeed true that Juramaia sinensis and other early eutherians did hibernate. Mevolutionary biologists now consider the origin of biological changes distinct to hibernation behaviors to have originated even before the evolution of class mammalia and are displayed even in reptiles who live in very warm environments.
Why did most mammals stop hibernating then? As the excellent paper The Evolution of Endothermy and Its Diversity in Mammals and Birds says “ energy-optimization-related selection pressures, often dictated by the energetic costs of reproduction, apparently favored abandonment of the capacity for short- or long-term torpors." In most primates, it seems this abandonment was characterized by a species with a large brain and increased adaptability to a variety of foods and climates.
That's too bad, because hibernation (or even torpor, a less extreme form) would be very useful for things like organ transplantations, surgery recoveries, or long space flights. In the future, if we figure out how to do it, being able to trigger hibernation would be incredibly useful. Unforunately, the exact way to trigger hibernation is not currently known, though there are many promising candidates. Dr. Kruse however believes that the stimuli is already known: “the stimulus for hibernation in eutherian mammals and their descendants are tied to high dietary carbohydrate intake (proven fact already in science and not controversial).” If only it were that easy. A search of the scientific literature found no papers that posited that carbohydrate consumption triggers hibernation, though it is established that carbohydrate metabolism undergoes changes before and after hibernation. Scientists who propose triggering hibernation believe it would probably involve injection of chemicals produced by hibernating animals. This would be possible because many of the genes related to hibernation are still present in primates, not because we hibernate, but because they have other functions. We'd also have to figure out how to prevent brain damage, which has been a major challenge to such research since humans appear to suffer memory loss from brain changes normal to hibernating mammals.
Evolution is efficient and while genes that had interesting past uses (wouldn't it be cool if we could "reawaken" gills or the ability to lay eggs??) are often conserved in our genome, they are often expressed in radically different ways. It seems the areas that once encoded for gills, for example, are now related to the bones in the ear. As for those that don't seem to be in use now, as geneticist Paul Szauter says:
If genes are not expressed in the human genome, they do not survive intact over evolutionary time, because they accumulate mutations in the absence of selection. If there were squid genes in the human genome that could be "activated," it is likely that the accumulated mutations would result in a truncated gene product (3 of the 64 codons are "stop") with many changes in its sequence.
Dr. Kruse believes that humans, like all mammals, are optimized for hibernation and that remnants of mammalian hibernation are activated in humans based on certain times of the day: "It appears 12-3 AM are the critical hours at night are where the remnants of mammalian hibernation lies for our species". This is a far cry from the current state on literature related to hibernation. The idea that remnants of hibernation occur in humans at night also goes against the definition of hibernation. An excellent paper authored by another McEwen, Dr. Bruce McEwen, has a great concise definition "Hibernation is a highly regulated physiological response to adverse environmental conditions characterized by hypothermia and drastic reductions of metabolic rate"
Re-definition and special unique definitions of terms is another of Melia’s characteristics of bad books: “ The texts of these books all continue in the same excited first-person voice. They often introduce vague, undefined or invented terms.” A good example of this is in Dr. Kruse’s PaleoFX talk, where he references “ geothermal circadian cycles.” It sounds scientific, but there are no known circadian cycles that are tied to Earth’s internal heat* and it appears Dr. Kruse invented the concept since it is found nowhere else. It is a particularly deceptive practice, made easier by the fact that many of the terms that are often mis-used by these authors, such as the species concept or even hibernation, are the subject of some academic contention. But while academics might be arguing about whether or not bears are “true hibernators,” we can be assured that no one is considering that humans are hibernating every night because that doesn’t even fit into the realm of contention or the fringes of what is considered hibernation.
The only known primate that hibernates is Cheirogaleus medius, member of suborder Strepsirrhini, which diverged from the evolutionary line that led to humans over 70 million years ago. They also store a lot of fat beforehand, so I don't know if I'd like to hibernate like them anyway. I don't think I'd look so good and I probably wouldn't get much work done.
Even if it were conserved, Dr. Kruse makes the mistake of tying hibernation to extreme cold: “Cold environments are found as mammals hibernate in normal circadian biology…….this completely reverses IR in mammals and wakes them up when conditions are better for life.” Dr. Kruse’s cold therapy involves exposure to freezing temperatures, because he thinks that is linked to hibernation in humans. Kruses asks his readers if maybe diabetes has “become thought of as a neolithic disease in humans because we we have simultaneously lost the ability to hibernate because we evolved the ability to control our environment completely?” However, there are many animals that hibernate without exposure to very cold temperatures and biologists are still debating whether or not relative cold is even needed to trigger hibernation at all. For example, the only hibernating primate, the aforementioned Cheirogaleus medius, hibernates at 30 degree celsius (86 F). And if humans had lost the ability to hibernate because we control our environment, we would find the ability in related primates who do not control their environments. But we do not. The northernmost living non-human primate, Macaca fuscata, does not show any evidence of hibernation or even torpor, even those that do not visit hot springs. Interestingly, their winter diet does include digging for roots.
Why do so few primates hibernate? Around the equator, where primates evolved, seasons operate quite differently than they do in the arctic and other regions far from the equator. Because the environments and climates of Africa are so diverse, with many micro-climates in certain regions, most primates closely related to humans have evolved to be able to adapt to scarcity regardless of Earth’s axis tilt through the reliance on “fall back foods.” Possibly because of this evolutionary strategy, there is no particular dietary pattern that consistently characterizes the seasons for primates as an order or even within species.
Even in non-primates that live in the north, a very small percentage hibernate. For example, some squirrels hibernate, some don't. Those that don't often will cache food and eat it later. Some humans are known to raid rodent caches for carbohydrates. This contrasts with Dr. Kruse’s idea of seasonal biological changes being triggered by changing to carbohydrates or one season being devoid of carbohydrates: “it appears that dietary carbohydrates, which are only present in long light cycles in the summer in cold places, induce mammals to add PUFA’s to our cells to become fluid so we can function as we hibernate.”
According to Kruse, since carbohydrate consumption is tied to hibernation in cold environments, since we don’t really hibernate now (except sort-of, at night according to Kruse), carbohydrates might not be safe to consume: “Since we no longer hibernate……..maybe you need to consider how you eat carbohydrates within the circadian controls? Maybe what you thought was safe………really is not?” The implication is that carbohydrate consumption is only “safe” for mammals in the context of nature’s “design” for hibernation. In terms of our evolutionary line, that makes little sense. The vast majority of primate species consume diets of mainly carbohydrate, with two main digestive strategies. The evidence is that ancestors of modern hominins relied on a mainly-carbohydrate diet until somewhat recently.
If Dr. Kruse’s line of reasoning is true, most primates are living out of balance with nature and have been for millions of years. Some of his followers have said that this only applies if you live in the north since there are somehow some circadian controls only in the North that are tied to carbohydrates (zero evidence provided), but then the mice and squirrels who are eating stored or underground roots are violating natures law. And the idea that if you put an individual primate in the north that it will change its underlying biology to fit the north's light cycles does not have any evidence behind it (and in fact the fact that individual humans don't adapt particularly well to northern light cycles is perhaps behind the etiology of many modern illnesses).
As I will write in my next post, some human populations (and possibly other hominin lines) have genetic adaptations to more polar light cycles, but these are recent adaptations and are not shared by all humans. And one unique thing is that humans that inhabit cold regions have a raised metabolic rate during the coldest season, not a lowered one characteristic of torpor or hibernation, which suggests adaptations more similar to those found in wolves rather than ground squirrels**. Also, I must also discuss longevity being derived rather than ancestral. But I'll leave that to the next post.
* Geothermal according to the OED is “ 1. Geol. Relating to or resulting from the internal heat of the earth; (of a locality or region) having hot springs, geysers, fumaroles, etc., heated by underlying magma.””
** are non-hibernating squirrels naughty "nature's law" breakers? Particularly if they are eating stored carbohydrates?