Is There an Optimal Diet for Humans?
February 13, 2019 7:26 AM   Subscribe

[NYT] Nutrition experts have long debated whether there is an optimal diet that humans evolved to eat. But a study published this month adds a twist. It found that there is likely no single natural diet that is best for human health. The research, published in the journal Obesity Reviews, looked at the diets, habits and physical activity levels of hundreds of modern hunter-gatherer groups and small-scale societies, whose lifestyles are similar to those of ancient populations. They found that they all exhibit generally excellent metabolic health while consuming a wide range of diets.
posted by ellieBOA (79 comments total) 60 users marked this as a favorite
 
"Eat food. Not too much."
posted by SansPoint at 7:27 AM on February 13, 2019 [23 favorites]


It doesn't mention that any of these groups eat crème eggs. Does that mean creme eggs must be the Death Food?
posted by biffa at 7:31 AM on February 13, 2019 [11 favorites]


Oh, I do love that they actually went ahead and reviewed this. My intuition for a long, long time has been that humans effectively evolved to eat anything that was reasonably nutritionally dense (e.g. not much in the way of cellulose or woody vegetation), not very toxic, and didn't run away fast enough. But it's always good to confirm that type of review and remind people of it, because there's a definite sense among e.g. 'paleo' devotees that there was some uniform human way of living in the distant past that humans everywhere adhered to, and having a convenient citation makes it easier by far to nudge people and remind them that humans have occupied a wide variety of ecological lifestyles across both space and time.
posted by sciatrix at 7:38 AM on February 13, 2019 [76 favorites]


This is super interesting.

Nitpicky comment: I would encourage people to move away from the phrase "evolved to do X." This wording implies that evolution is going toward something, that there is an end goal. Evolution doesn't have an end point or a goal. Sure, we likely evolved eating lots of stuff. That doesn't mean eating lots of stuff is our destiny. We are continuing to evolve.
posted by medusa at 7:42 AM on February 13, 2019 [60 favorites]


One of the very few things I am certain of at the age of 45 is that there is never One Perfect Thing that is going to work for everyone - whether you're talking about diet or philosophy or religion or organizing strategies or flavours of ice cream - and anyone who tells you that there is is selling you a line, most likely in pursuit of power and/or profit.

> Does that mean creme eggs must be the Death Food?

The Death Food is those dipping sauces that come with cheap pizza, although come to think of it they're probably more or less the same aside from their salt/sugar content.
posted by The Card Cheat at 7:43 AM on February 13, 2019 [13 favorites]


sciatrix, I think "Not Very Toxic, and Didn't Run Away Fast Enough" would be an excellent title for a cookbook.
posted by mandolin conspiracy at 7:50 AM on February 13, 2019 [133 favorites]


Yeah, I heard an argument recently (not sure where) along these lines. That we don’t have the “one true diet” because humans have incredible adaptability built into our dna. That is our niche. Not that anyone can eat anything. But as a species and population, we seem to be able to adapt to almost anything.
posted by [insert clever name here] at 8:01 AM on February 13, 2019 [6 favorites]


It's pretty amazing that while humans have adapted to be metabolically healthy with a very wide variety of diets, our food supply system still manages to deliver mostly shit and provide extremely inadequate nutrition and health.
posted by entropone at 8:02 AM on February 13, 2019 [18 favorites]


I mean...we know this from other scavengers and omnivores, right? Like bears and racoons (which, I suppose, are just trashy little bears).

Ditto on sciatrix's point on Paleo folks. In general, I'm always bummed how easily people (all of us, me too!) fall into stupid logic traps when considering evolution. Like, we have the failed ideas of evolution-based racism to act as a warning, but we keep coming up with dumb ideas. Even folks like Robert Wright and Pinker and Dennett who do great evolutionary psychology work fall into stupid sexism in their early (And sometimes later) work.
posted by es_de_bah at 8:04 AM on February 13, 2019 [14 favorites]


Agreed that the "evolved to" thing is weirdly teleological.

On the other side of the coin, just because humans (and most canines/ursines/Suidae) are able to get nutrition from an expansive variety of foods, that doesn't necessarily mean any particular diet is optimal.
posted by aspersioncast at 8:04 AM on February 13, 2019 [3 favorites]


Brenna Hassett, a bioarchaeologist who studies how humans changed as we went from hunting and gathering to agriculture and urbanization, was asked in an interview about the whole paleo and what we evolved to eat question. Her answer was "Humans evolved not to starve" in such a dismissive tone that I immediately got her book (Built on Bones. Didn't regret my decision.)

(She did elaborate that we find pretty much everything that could be eaten was eaten, anything they could catch from mastodons to hedgehogs and also "carbs, lots of carbs.")
posted by mark k at 8:05 AM on February 13, 2019 [43 favorites]


yeah the 'evolved' angle is sort of pointless I think? we evolved as opportunistic trash monkeys.
posted by supermedusa at 8:12 AM on February 13, 2019 [27 favorites]


Nitpicky comment: I would encourage people to move away from the phrase "evolved to do X." This wording implies that evolution is going toward something, that there is an end goal. Evolution doesn't have an end point or a goal. Sure, we likely evolved eating lots of stuff. That doesn't mean eating lots of stuff is our destiny. We are continuing to evolve.

Absolutely, and the phrasing "evolved to do" implies a teleological view of evolution, where every day in every way we get better and better adapted to our environment.

In the case of nutrition, all you have to do to poke a hole in that kind of thinking is to point out that, very early in the evolution of primates, they lost the ability to synthesize vitamin C.

Presumably their diets provided enough vitamin C that this accidental loss didn't apply much selection pressure, but here we are, millennia later, and we're subject to scurvy due to a copy-paste error of a scrap of DNA. Not requiring an external supply of vitamin C would make a huge difference in the range of healthy diets for humans, but too bad for us.
posted by murphy slaw at 8:13 AM on February 13, 2019 [21 favorites]


Nitpicky comment: I would encourage people to move away from the phrase "evolved to do X."
-medusa

What's a good alternative? I see how the phrase can be misconstrued, but it's not really wrong, right? The phrase "Na bonds with Cl to gain stability" doesn't necessarily invite the pathetic fallacy or suggest that this is the end of the story. Still, if you have a better way of putting it for clarity, how would you phrase it?
posted by es_de_bah at 8:18 AM on February 13, 2019 [2 favorites]


I like to watch the Primitive Technology and survival YouTube channels, and I also read occasional post apocalyptic Sci Fi. And I think a great deal of us overestimate both our overall chances of survival, and we also commit some interesting errors about how elective diets can be among folks of marginal means and existence.

Especially the protein bar chomping paleo weirdos. But also all of us. I think the real paleo diet is quite a bit more like sciatrix formulated. By necessity if we're not agrarian and more hunter-gatherer, we eat what we can find. It's not like every human era even had grocery stores. That only happens with a certain level of shared community and stable living arrangements.
posted by kalessin at 8:21 AM on February 13, 2019 [3 favorites]


We evolved to eat as much salt, sugar, and fat that we could get our grubby little primate hands on, and the problem is now we can eat as much of it as we want.
posted by condour75 at 8:21 AM on February 13, 2019 [32 favorites]


Evolved to do x is super teleological and implies a purpose. It's a similar fallacy to those that result in confirmation bias, and in misinterpreting the theory of evolution.

In these cases, a more accurate phrasing would be something like, "various organisms that could do X gained an advantage in Y context" which much better acknowledges the role of chance in evolution.
posted by kalessin at 8:25 AM on February 13, 2019 [9 favorites]


"Even folks like Robert Wright and Pinker and Dennett who do great evolutionary psychology work fall into stupid sexism in their early (And sometimes later) work." I don't know Wright and don't much care for Pinker, but Dennett? Stupid sexism? What do you have in mind?
posted by holist at 8:29 AM on February 13, 2019


our food supply system still manages to deliver mostly shit

The average grocery store has about 50,000 items. People have a lot of choices. In general, we choose to eat shit.

Are they eating crap because of the way we subsidize the ingredients? Nope. (It's a factor, but a very small one.)

Sure, but what about people in food deserts? They would eat better if they had access to healthy food, right? Nope.

People eat what's easy, fast, tasty, and cheap. Generally, those things are highly processed and unhealthy.

There are plenty of policies - nutrition education, subsidizing healthier food and taxing unhealthy food, etc. - to encourage healthier eating, but those are the facts that those policies will have to deal with.
posted by Mr.Know-it-some at 8:29 AM on February 13, 2019 [18 favorites]


The main thing is to move your ass.
posted by Burhanistan at 8:29 AM on February 13, 2019 [5 favorites]


Most of their carbohydrates come from vegetables and starchy plants with a low glycemic index, meaning they do not lead to rapid spikes in blood sugar.

Yep. There's your lack of diabetes, obesity, and other diseases of modern diets.

We evolved to eat as much salt, sugar, and fat that we could get our grubby little primate hands on, and the problem is now we can eat as much of it as we want.

We do not have insatiable appetites by default.
posted by MillMan at 8:30 AM on February 13, 2019 [2 favorites]


Metafilter: opportunistic trash monkeys
posted by Kitty Stardust at 8:32 AM on February 13, 2019 [26 favorites]


How does this work? "evolved to devour delicious chocolate"
posted by sammyo at 8:32 AM on February 13, 2019 [6 favorites]


Generally, those things are highly processed and unhealthy.

Point of order: this is in no way a conflation upheld in the scientific literature. The science here doesn't hold rigorous water. Currently there are highly problematic (methodologically) and embattled statistical correlations in diet, metabolism, obesity, fitness, etc. But I personally recommend care in asserting or defending this relationship.
posted by kalessin at 8:33 AM on February 13, 2019 [11 favorites]


This is exactly what I was taught in college anthropology classes like a decade ago, and it was cited as one of the biggest reasons humans were able to colonize essentially the entire planet - because we can move to new places with totally different types of food and just roll with it.
posted by showbiz_liz at 8:34 AM on February 13, 2019 [9 favorites]


> Does that mean creme eggs must be the Death Food?

The Death Food is those dipping sauces that come with cheap pizza, although come to think of it they're probably more or less the same aside from their salt/sugar content.


Man, I love those things. Death Sauce for my Death Pie.

(in the name of moderation, I rarely finish the container - last time I threw out 3/4).
posted by jb at 8:43 AM on February 13, 2019 [3 favorites]


holist, I'd have to search to find the Dennett stuff. I think in his case it's mostly in the form of jokes, as his strength is definitely in fighting fuzzy thinking on evolution. It's clearest in Pinker, who I love but has always worked 'pwning the ultra-libs of academia' into his persona. Robert Wright has grown ever more thoughtful over the years, but The Moral Animal is super smug about evolutionary psychology explaining sexist ideas, almost to the point where he's excusing them. It's a pretty jarring reminder of 90s sexual politics.
posted by es_de_bah at 8:43 AM on February 13, 2019 [1 favorite]


I'd respect paleo-is-the-true-diet evangelists more if they chomped down on grubs. Which were likely a much more regular part of the protein supply of early humans than large, dangerous and often seasonal large mammals. Yet somehow it's always steak.
posted by tavella at 8:51 AM on February 13, 2019 [36 favorites]


chomped down on grubs

And I just caught the movie "Border" yesterday!
posted by Burhanistan at 8:55 AM on February 13, 2019


"It doesn't mention that any of these groups eat crème eggs. Does that mean creme eggs must be the Death Food?"

All of these groups are 100% dead. It's possible a cream based diet may have saved them all, we can never know now. Either way, we shouldn't look to these goobers for tips on how to eat, anyone actually good at eating would still be here to tell us.
posted by GoblinHoney at 9:00 AM on February 13, 2019 [9 favorites]


We do not have insatiable appetites by default.

True, but the instinctive balance is probably something like "eat as much fat, sugar, and salt as you can until you have an eighty/twenty chance of being able to run away from a lion because it may be weeks of eating grubs before this opportunity arises again and it's not like there's refrigerators out here in the rift valley", which is not very helpful when there's a large bag of Taki Rolls in front of you and they're just so goddamn crunchy and salty.
posted by condour75 at 9:00 AM on February 13, 2019 [10 favorites]


Huh, everything I've read by Pinker (admittedly not a ton) barely clears the Gladwell bar for unprovable/untestable/unknowable opinion presented as an assertion fact. Is his earlier stuff actually scientific? Evolutionary psychology in general rings a lot of "woo" bells for me.
posted by aspersioncast at 9:00 AM on February 13, 2019 [14 favorites]


We only had to live long enough to have kids and get them raised, so we never had to "healthy" in the woo, cleansing, "eating pure" sense. We were more than likely going to die by infection, disease or random accident before we got to be too old anyway.

Most obsessive diets are about a mythical kind of body purity that has never existed and can never exist.

Which doesn't mean a diet of shitty fast food won't make you feel like crap.
posted by emjaybee at 9:03 AM on February 13, 2019 [14 favorites]


Doritos don't occur anywhere in nature.
posted by Damienmce at 9:05 AM on February 13, 2019 [9 favorites]


^
Is heaven nature?
posted by dudemanlives at 9:09 AM on February 13, 2019 [15 favorites]


One of the things I have been meaning to dig into for weeks is that there's a hormonal relationship, even a strong hormonal relationship, between cortisol (usually studied in terms of stress response) and leptin (usually studied as a satiety hormone, produced by adipose tissue, and the subject of my PhD). It is adversarial: the two of them erode one another. I haven't had time to delve deeper than that, but I want to very badly.

There is also some evidence that the emotional and expectational experience we bring to food affects how we digest it and how satisfied we are by the experience of eating it. For example, people told that a milkshake was indulgent experienced more ghrelin release and expressed more satisfaction than people who consumed the same milkshake but were told it was a diet, virtuous product. Same thing, but our expectations shape how we respond to food. Satiety and motivation to eat are not things that boil down to "calories-in-full-calories-out-not-full", and it's really disingenuous to say that we definitely know why obesity is common or why people maintain higher body weights or why people select particular foods, because we... really, really don't.
posted by sciatrix at 9:10 AM on February 13, 2019 [44 favorites]


Looked at the NYT article and glanced at the original article (12/18), and the NYT suggests there is a good diet: a) high fiber b) lots of exercise c) boring menu with few options; the summary in the article only goes so far as to say:
Diets in hunter‐gatherer and other small‐scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued.

So a little less assertive than the NYT article implies. But in the end, the authors remark:
Finally, it is worth considering what other aspects of traditional lifestyles, in addition to diet and physical activity, might contribute to the remarkable health of hunter‐gatherers. Close friendships and family bonds, low levels of social and economic inequality and lots of time spent outdoors are typical in hunter‐gatherer populations and other small‐scale societies. The absence of these in modern societies is associated with chronic social stress and a range of non‐communicable diseases, including metabolic disease and obesity

posted by Peach at 9:10 AM on February 13, 2019 [3 favorites]


Which doesn't mean a diet of shitty fast food won't make you feel like crap.

Will it though? IME it's the social shaming that tends to make folks feel like poo. The food is delicious to a lot of folks for a reason.

I'm diabetic/prediabetic and as such I'm on a program of diet and exercise that helps me feel (internally) better than if I aimlessly fulfill every passing craving. But I know plenty of people who eat/graze kind of impulsively who don't feel like crap until someone criticizes them for unintentional eating. I think food shaming sucks and I think we do it to each other constantly and tend to discount the physical effects of being shamed. As a health issue.
posted by kalessin at 9:12 AM on February 13, 2019 [19 favorites]


tl; dr: be very, very careful about describing 'default' human appetites and motivations for particular foods, because there's a surprising amount of collateral factors that seriously influence how people relate to and digest food based on emotional expectation, familiarity, and overarching stress state, not to mention epigenetic influence from developmental contexts, past experience, and even some transgenerational influence.

Energy balance is hard.
posted by sciatrix at 9:13 AM on February 13, 2019 [9 favorites]


Doritos don't occur anywhere in nature.

death-cap mushrooms don't occur anywhere in mcdonald's
posted by murphy slaw at 9:16 AM on February 13, 2019 [30 favorites]


The average grocery store has about 50,000 items. People have a lot of choices. In general, we choose to eat shit.

Are they eating crap because of the way we subsidize the ingredients? Nope. (It's a factor, but a very small one.)

Sure, but what about people in food deserts? They would eat better if they had access to healthy food, right? Nope.

People eat what's easy, fast, tasty, and cheap. Generally, those things are highly processed and unhealthy.

There are plenty of policies - nutrition education, subsidizing healthier food and taxing unhealthy food, etc. - to encourage healthier eating, but those are the facts that those policies will have to deal with.


All good points - there ARE inherent policy difficulties in a system that involves distribution and marketing AND people's choices. Dwelling on the latter, though, drifts perilously close to a "personal responsibility" take on the issue. After all, if our choices were something that we owned entirely and weren't affected by a host of external (and changeable!) factors, why would anybody spend money to advertise?

There are ways that I think lessons from tobacco's history can be applied - implementing policies that make it harder to put addictive, unhealthy substances into children; imposing additional costs where externalities were hidden ... make it harder to choose stuff that, in the long run, isn't good for us.

This touches on huge issues of inequality in the country, too - what people choose, how much it costs, and how much time they have to actually address this stuff as if it were a *choice* and not the path of least resistance.

But I think we're more or less on the same plane here.
posted by entropone at 9:39 AM on February 13, 2019 [4 favorites]


I guess my thought about diet is that if we start by getting everyone secure, comfortable housing, access to all the medical care they need, access to transit, equal access to education, security for retired and disabled people, childcare and access to sufficient food in standard variety, we can hack the rest later. Once we've got rid of the health problems that come from not having medical care, having very limited access to weird varieties of food only, drug and alcohol dependency and the stress of material insecurity, we'll have a much better idea of what actually needs to be addressed via society-wide diet recommendations.

An awful lot of this "what is the best thing we can eat" stuff seems like it's putting the cart before the horse when it's applied to society as a whole. Start by making sure that everyone is materially secure, then refine to the best kind of security.
posted by Frowner at 9:40 AM on February 13, 2019 [71 favorites]


I feel ya, Frowner. I work in public health in a major US city and often it feels like slapping band-aids on poverty and inequality.
posted by entropone at 9:43 AM on February 13, 2019 [7 favorites]


Absolutely, Frowner, and this is one of the things I was getting at with my comment on leptin and cortisol: stress and uncertainty fuck with energy balance, they fuck with your brain, they fuck with your gut, they fuck with your fat pads, and your body responds differently based on the amount of life stress you are dealing with.

You can't fix energy balance issues or obesity or anything on a public health level before you deal with material insecurity, particularly in this time of incredible fear, stress, and precarity for so many people.
posted by sciatrix at 9:54 AM on February 13, 2019 [19 favorites]


death-cap mushrooms don't occur anywhere in mcdonald's

Having tasted a Shamrock Shake once, I tend to disagree.
posted by delfin at 10:01 AM on February 13, 2019 [6 favorites]


metafilter: just trashy little bears
posted by rude.boy at 10:08 AM on February 13, 2019 [6 favorites]


There is also some evidence that the emotional and expectational experience we bring to food affects how we digest it and how satisfied we are by the experience of eating it.

I was listening to a Gastropod episode on soft drinks about this, and how whether we consider something a liquid or a solid affects how full that makes us -- if you add 200 calories of solid food for a meal, like pizza, you will eat less in subsequent meals, while if you add 200 calories of a soft drink, you will not.

And then:
MATTES: We did a trial a few years ago where we told people that a food would be a liquid or solid in their stomach after it was consumed.

GRABER: It didn’t matter what they were told—in fact, it was always actually just clear liquid. But if the participants thought they had a solid food in their body, their hunger dropped, their stomachs actually physically stayed full longer. The liquid even took longer to pass through their intestines. Just because they thought it was solid. Rick’s not sure why.

MATTES: I think the mechanistic explanations are not defined in great specificity but it’s clear that we handle liquids and solids very differently, biologically.
I haven't followed up reading about this, but it feels like it's related.
posted by jeather at 10:09 AM on February 13, 2019 [20 favorites]


I haven't read the full research article, and I apologize if anyone mentioned this previously, but I wager main difference between health in HG populations and industrialized populations are not so much amount of physical activity and diet as much as it is the effects of modern sources of stress on the body's ability to digest and metabolize what we eat. So it doesn't really matter how much you exercise at the gym or if you avoid the Doritos, if your body is constantly producing stress hormones and reacting to stresses that we never physically evolved to endure (even something as seemingly trite as the stress of boredom or poor lighting or such things particular to office environments) you're still going to wind up with issues such as obesity, hormone disorders, and other diseases that are not as prevalent in HG societies.

Granted those Doritos don't help.
posted by Young Kullervo at 11:13 AM on February 13, 2019 [3 favorites]


stresses that we never physically evolved to endure

From the looks of it we are in the process of evolving to endure these stresses.
posted by grumpybear69 at 11:15 AM on February 13, 2019 [1 favorite]


Well, if by evolving you mean shortening our average lifespan via disease and widespread mental illness and the effects thereof, then I agree. Not being snarky, but none of it seems to be advancing our species as anything other than anxious, depressed drones. I could be wrong though.
posted by Young Kullervo at 11:21 AM on February 13, 2019 [2 favorites]


The combination of enjoyable snark and actually fascinating information (thanks sciatrix!) in this thread is hitting my brain's pleasure centers exactly like hot, salty McDonald's fries
posted by sunset in snow country at 11:22 AM on February 13, 2019 [17 favorites]


Clearly from an environmental standpoint the best thing we can eat is each other, right?
posted by aspersioncast at 11:24 AM on February 13, 2019 [2 favorites]


Young Kullervo: "Well, if by evolving you mean shortening our average lifespan via disease and widespread mental illness and the effects thereof, then I agree. Not being snarky, but none of it seems to be advancing our species as anything other than anxious, depressed drones. I could be wrong though."

That's the thing about evolving... it doesn't mean advancing towards something. It means the ones who can't hack the environment die off, and the ones who can survive.
posted by team lowkey at 11:36 AM on February 13, 2019 [7 favorites]


all evolution 'cares about' is that you survive long enough to spawn. that is a REALLY low bar.

look me run faster than Thog, not get eat by bear!
posted by supermedusa at 11:42 AM on February 13, 2019 [8 favorites]


One of my anthropology professors was fond of stating “Humans have no instincts,” as a way to rile people up (naturally), but also to remind us that though there are plenty of genetic tendencies leaning on our behaviors, there are no functions normally associated with instincts that you don’t find exception to in one human society or another—in other words, no behaviors over which we—through culture—cannot exert control.

This evolutionary biology narrative’s been all the rage the past 20 years, smugly confident it’s explaining human behavior.  Meanwhile the cultural anthropologists have been politely raising their collective hands the same length of time saying, “Guys, guys, it’s more complicated than that,” while being dismissed with a condescending wave and instructions to let the big boys of hard science handle this.  Nature versus nurture is the usual way of expressing the argument, and I know which side of it I fall on, which is to say I’ve never believed this “evolved to gorge ourselves and we cannot help it” narrative that pops up all the time.  It conveniently absolves us of guilt which makes it popular, but honestly, it’s not needed.  Perhaps we do have genetic tendencies leaning on us, pushing us to favor crap, but our eating habits are culturally ingrained—which makes them no less difficult to control.  It just boggles my mind that we’re this far into the debate over what is the ‘natural’ human diet when any anthropologist could point out all the wildly different diets humans have used throughout our evolution.  And it’s not like evolution stopped with agriculture or pastoralism.  I’m 49, and thanks to an historically recent genetic mutation in my ancestors from Northwest Asia, I can still digest cow’s milk in my diet as an adult—a mutation most the human species does not possess.  Which diet am I supposed to hold up as the ‘natural’ one?

Immigrants end up with shitty diets in the West because that is what our our culture eats, and they’re now immersed in it, not because humans can’t control their appetites.  We’re surrounded by ads for food, 24/7, it’s no wonder people have difficulty with diets, we’re pushed constantly to eat crap.  We’ve boxed ourselves into this dietary corner through our culture, step by step, and we’re only going to get out of it the same way.  But here’s the upshot—in the end, this is a far, far more hopeful way to look at our issue.  Were the evolutionary biologists right, we’d just be collectively fucked. But if nurture vs nature is right…well, culture changes—slowly to be sure, but a hell of a lot faster than our genome, and unlike the genome is under our collective control.
posted by los pantalones del muerte at 11:54 AM on February 13, 2019 [10 favorites]


Well of course evolution serves no purpose but survival.

But I don't really enjoy thinking about how the rich are going to be the only genetically "sound" beings left on the planet and ultimately overlords while the average schmuck eventually died off or is currently fat, diseased, deranged, glued to a screen for random endorphin hits, can only work in the trenches, and dies horribly when they're 32.
posted by Young Kullervo at 12:07 PM on February 13, 2019 [1 favorite]


But I don't really enjoy thinking about how the rich are going to be the only genetically "sound" beings left on the planet

It's not fucking genetics. It's circumstance.

Ahem. This is a thing that I get extremely angry and frustrated about: so many of these things are so heavily influenced by stress, or socioeconomic status, or or or, and yet people talk about them as though genetic "quality" is a thing. Yet if you adopt a poor child into a wealthy and emotionally healthy and affectionate family, somehow all their genetic "poor quality" melts away.

It's poor science, but it pops up over and over and over and over again in both human evolution and animal evolution work, with only vague discussions of what "quality" even means, and the best explanations in the animal literature tend to be "goodness of fit between an individual's genes and the environment," including disease resistance and ecological suitability to the vagaries of the day. But stochasticisity--random chance and luck--and the effects of hierarchy and hereditary transfer of resources are curiously underconsidered in these things, particularly the former; the latter are mostly studied in the context of matrilines but are rarely considered in the context of the sorts of things that are considered in terms of "genetic quality." The common garden experiment is curiously uncommon when it comes to ranking animals by their inherent quality, and still rarer is comparing animal lines among several common gardens to study behavioral outcomes.

It makes me so frustrated! It is not genetic quality if whatever the thing is associates only with people who are rich in resources, and yet people consistently choose to imagine that the wealthy are genetically entitled to their social position over and over and over again!

Also, nature vs. nurture is a non-argument: you cannot have one without the other, and their interaction is what creates a human being. Nurture without nature to shape it is empty air; nature without nurture to grow it is just a little vial of DNA, or perhaps a single pair of germ cells dubiously dancing within it. Nurture is time and history; you can't isolate an iota of potential without giving it a particular history of growth and development to allow it to create a phenotype.
posted by sciatrix at 12:19 PM on February 13, 2019 [32 favorites]


If we decided to upend this curious social experiment where we determine worth by inherited and "earned" numbers, where by chance and circumstances, some of us have very large numbers and many of us have very small numbers, I agree that evolutionary fitness would also have to be seriously re-evaluated. Right now we tend to elevate people who, beyond their personal numbers are absolute and complete tools otherwise, and further, who themselves subscribe to some philosophical exceptionalism in order to avoid feeling badly about treating small number people exceptionally poorly.
posted by kalessin at 12:34 PM on February 13, 2019 [1 favorite]


Also, nature vs. nurture is a non-argument: you cannot have one without the other, and their interaction is what creates a human being.

I like the cut of your jib!  Now how do we remind everyone writing shitty science articles that it's more complicated than whatever narrative the latest just-so story is all the rage makes it.
posted by los pantalones del muerte at 12:34 PM on February 13, 2019 [2 favorites]


This is a thing that I get extremely angry and frustrated about: so many of these things are so heavily influenced by stress, or socioeconomic status, or or or, and yet people talk about them as though genetic "quality" is a thing. Yet if you adopt a poor child into a wealthy and emotionally healthy and affectionate family, somehow all their genetic "poor quality" melts away.

I think you misread me, unless you're just commenting off of what I wrote because you agree. So I agree with you, and I wasn't implying that the rich are or will be automatically genetically superior or that nature versus nurture is not a valid theory, but I think you're maybe forgetting genetic disorders that disproportionately plague populations who have been systemically oppressed for centuries that are passed down to their offspring throughout generations. These things cannot be "nurtured" away in an individual and really were the focus of my hypothetical speculation where the average person similarly becomes another oppressed population doomed to genetic dysfunction. I'm saying the rich will continue to nurture their own thus shielding them from these disorders BECAUSE they won't have to deal with the complications of stress and other environmental aspects you mention, which was...sort of the point of my post I guess. I don't like speculating about that.
posted by Young Kullervo at 12:42 PM on February 13, 2019 [3 favorites]


So, this doesn't necessarily undermine the article's insights BUT…

…portraying 21st-century hunter-gatherers as a window into humanity's evolutionary past is not a cute look.
posted by LMGM at 12:45 PM on February 13, 2019 [14 favorites]


I think you misread me, unless you're just commenting off of what I wrote because you agree.

*rubs forehead* It's the latter. It's just this particular rage point is the driving motivation behind my actual thesis, and I'll wax furious on it at the drop of a hat. I'm not mad at you, I'm just--AUGH PEOPLE.

Also, yeah, absolutely pop science people need to fucking internalize that "nature vs. nurture" has been dead as a serious argument in psychology for at least twenty years.
posted by sciatrix at 12:53 PM on February 13, 2019 [5 favorites]


This isn’t at all scientific and, warning, I’m tired. Just want to say that although there’s lots that’s unknown, and sure tons of important 3rd factors matter (psychological expectations, stress, inequality, car culture - it is *definitely* overdetermined, no doubt), I still feel like it’s blindingly obvious that obesity’s supercharged skyrocket from the 80s on has got *something* to do with the supersized portions available since then.

80s - eat food a person you know probably cooked 3 times a day, in normal portions, treats are occasional *treats* not daily habits, walk/run/cycle around more

Now: ENORMOUS servings of fast food priced and marketed for volume consumption, Starbucks and/or some kind of treat, every day, people not moving around at ALL

(I LOVE a quarter cheese and I fully appreciate the impact of inequality, capitalism, etc so no judge, but there’s no reason any person needs an actual JUG of Coke with their combo.) TLDR, proximal cause is portion distortion
posted by cotton dress sock at 2:08 PM on February 13, 2019 [1 favorite]


I am not up-to-the-minute current with obesity statistics but it's worth noting that the folks whose jobs depend on statistical findings falling their way (for fundraising purposes) have been playing fast and loose with statistics and rhetoric since the mid 20th century.

The situation is so bad that when I was up-to-the-minute, I found that no one could meaningfully say with definitiveness from a scientific standpoint whether the rise in obesity is actually a real thing and not a product of shifting definitions, policy, and perceptions.
posted by kalessin at 2:15 PM on February 13, 2019 [5 favorites]


Brains are weird yo
posted by bq at 3:15 PM on February 13, 2019


Cntl F "microbiome" not found
Cntl F "sociology" not found

Enh.
posted by eustatic at 4:20 PM on February 13, 2019


LMGM: …portraying 21st-century hunter-gatherers as a window into humanity's evolutionary past is not a cute look.

I'm reminded of the recent (re)discovery of the fact that many of the people living in the Amazon rainforest descend from large-scale agricultural civilizations which were there until Eurasian diseases arrived. In those cases, the hunter-gatherer lifestyle isn't aeons old; it's a few centuries old, a cultural adaptation to the fact that living too close together suddenly became deadly.
posted by clawsoon at 5:12 PM on February 13, 2019 [15 favorites]


Similarly, IIRC James Scott's The Art of Not Being Governed asserts that a lot of modern hunter-gatherer groups in SE Asia have retrenched or even (re)invented "traditions" at least in part in response to internal colonization by the state.

I found that no one could meaningfully say with definitiveness from a scientific standpoint whether the rise in obesity is actually a real thing


Really? I thought the medical literature was pretty solid on this; now I'm wondering if I've just extrapolated from secondary sources and poor reporting.
posted by aspersioncast at 9:09 PM on February 13, 2019 [3 favorites]


Yes, really. But it's hard to call. Which is a shitty place to be. Because the science is clouded and obscured and used for propaganda. That it is a hard call with muddies and difficult to verify findings is itself a fucking huge problem. That's what every evidence based policy maker has to contend with: uncertain science made more uncertain with rhetoric.
posted by kalessin at 9:32 PM on February 13, 2019 [1 favorite]


When you eat, particles of food can get crushed into your teeth. I've read about studies of the teeth ancient hunter gatherer societies to find out what they ate, and the conclusions were basically the same as this study. They ate whatever was available--some places a higher percentage of meat, and some places a higher percentage of vegetables and grains.

Whether or not there's an advantage to a 'paleo diet', saying that it is based on the diet of ancient humans is nonsense.
posted by eye of newt at 12:05 AM on February 14, 2019 [4 favorites]


I like the cut of your jib! Now how do we remind everyone writing shitty science articles that it's more complicated than whatever narrative the latest just-so story is all the rage makes it.

We make them read Bandura...?
posted by entropone at 4:53 AM on February 14, 2019


Yet if you adopt a poor child into a wealthy and emotionally healthy and affectionate family, somehow all their genetic "poor quality" melts away.

Anyone who's reading this will I'm sure agree with you that social class plays a unconscionably large part in a child's outcomes; inequality of both opportunity and outcome in the United States is one of the, if not the, largest social problems.

But what you wrote ("all") makes it sound like genes don't matter; of course, they do. Many of the factors that affect success, however you define it, are significantly heritable.
posted by Mr.Know-it-some at 6:14 AM on February 14, 2019 [1 favorite]


Mr.Know-it-some: Many of the factors that affect success, however you define it, are significantly heritable.

The lower your socioeconomic status, the less heritable those factors are. Or... it's not that they're less heritable, it's that there's larger environmental variation, which makes heritable variation smaller by comparison. Two well-off children are going to grow up in unpoisoned houses in unpoisoned neighbourhoods with good healthcare, and much of the difference between them will be genetic. Two poor children are going to be subject to environmental lotteries. Maybe they'll get lead paint; maybe they'll get pesticides; maybe they won't get treatment for treatable diseases; maybe they'll get lucky. Genetic differences will matter less.

This is reflected in adoption studies which have found an average 10-15 point gain in performance on IQ tests as a result of being adopted into a high-SES family.

Another interesting thing I read in a large-scale genetic study in the past year - though I'm having trouble finding it at work right now - is that there are some genes which show that they have a heritable effect even if they aren't inherited. IOW, if your parent has the allele, you get benefits, even if you don't inherit the allele. (It was one of the studies which found that the top few hundred genes explain 10%-ish of the variation one some measure of intelligence or another.)
posted by clawsoon at 10:29 AM on February 14, 2019 [9 favorites]


Came back to report that it turns out my optimal diet is 5-6 ounces of Gin Lane's 1751 'Victoria' Pink Gin, about half an ounce of Noilly Prat Dry, two olives, and two cocktail onions.

I ate something delicious beforehand, but it was just empty nutrition.
posted by aspersioncast at 10:48 AM on February 14, 2019 [6 favorites]


Ah, here's the quote:
Consistent with this hypothesis, a recent paper reports that a polygenic score for EduYears based entirely on the non-transmitted alleles of the parents is approximately 30% as predictive as a polygenic score based on transmitted alleles. (For height, the analogous estimate is only 6%.) - Gene discovery and polygenic prediction from a genome-wide association study of educational attainment in 1.1 million individuals [PDF]
posted by clawsoon at 10:52 AM on February 14, 2019 [3 favorites]


Why would industrialized populations be more stressed than HG populations? I don't think most of us experience travel in vehicles as the persistent mortal threat that it is.
posted by Selena777 at 9:14 AM on February 15, 2019 [1 favorite]


Two words: income inequality.
posted by sciatrix at 9:41 AM on February 15, 2019 [4 favorites]


I don't think most of us experience travel in vehicles as the persistent mortal threat that it is.

As someone who rarely drives and has never owned a car, I have often noticed a shift in mood among friends who offer me a ride here or there. They are a bit more likely to snap at people driving other cars when they make a mistake. One sometimes hears the phrase, "You could have killed someone!" uttered in reference to such carelessness. I have yelled from my bike at cars making similar mistakes, such as driving without headlights at night, or turning in front of me without signaling ahead of time.

By contrast, no one yells at a passerby walking down the sidewalk when they pass by a little too closely. Even in crowds, no one honks their horn or yells to get things moving. A walk in the woods in peacetime, even if you're walking through bear country, is less stressful than a drive down even a slightly busy road. It's not the woods that makes it nice, either: I've walked down the middle of a small-town street at night when there is absolutely no traffic, and it's almost as stress-free. If driving in traffic is what you do all the time, you may not even notice the extra stress any more, but I think it shows. It's why we think of a walk in the woods as wonderfully relaxing, when it used to just be normal for everyone.

Also: income equality.
posted by skoosh at 10:22 AM on February 15, 2019 [5 favorites]


skoosh: It's why we think of a walk in the woods as wonderfully relaxing, when it used to just be normal for everyone.

This is cultural, too. In The Forest People, Turnbull described how the Mbuti loved the forest, but the nearby Bantu saw it as full of dangerous animals and evil spirits. For the Bantu of that time and place, the forest was a site of deep fear to be avoided at all costs. (Many things have changed in the Congo since then, and there are different sources of fear and horror now.)

I've read similar quotes from pre-Romantic Europeans, though I'm having trouble finding them now. Urbanites thinking of the forest as beautiful and relaxing instead of a fearsome wasteland is in some ways a Romantic invention.
posted by clawsoon at 5:15 AM on February 17, 2019 [4 favorites]


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