Friday, August 12, 2011

Comment on Guyenet vs. Taubes; or Why I Don't Give a Crap What the Kitavans Eat

This post started as a comment to Stephan Guyenet's excellent post on the carbohydrate hypothesis of obesity, got too long, and so I'm putting it here. Do read Stephan's post, and keep an open mind. It's got loads of interesting and cutting-edge science, and this sort of debate and information exchange is how science progresses. If you find yourself experiencing cognitive dissonance, remember that absolute belief is antithetical to science. We always must update our beliefs as new information emerges.

Short summary of Stephan's blog post: the hypothesis that carbohydrates in general are fattening is probably over-simplified and does not reflect the most recent scientific understanding of metabolic regulation. It also leads one into a variety of paradoxes, a la the "French Paradox" of the diet-heart hypothesis.

I think part of what we're seeing here is the rather poor taxonomy of nutrition. We discuss things in terms of macronutrients, but those macronutrients come with (or without) all kinds of other metabolically relevant substances. And even within a given macronutrient group there can be significant metabolic differences, e.g. for fatty acids of different chain lengths, or between glucose and fructose (though Dr. Feinman might have something to say about the latter).

I've posted here before on my favorite example of this, and it seems like a good time to revisit (working from memory and about 4 hours of sleep, so please correct me if necessary). The Aztecs had a corn-based diet. They did experience obesity, but despite documenting a wide variety of health issues in detail never described diabetes. The Egyptians ate a wheat-based diet, also experienced obesity (along with heart disease, cancer, and the whole host of other fun "diseases of civilization"), and did document diabetes. Two high-carb diets, both resulting in some level of obesity, but from what we can tell (thousands of years later), both having radically different metabolic endpoints.

Two take-home points here. First is that we likely need to consider a broader dietary context than that imposed by our artificial macronutrient classification scheme, i.e. wheat and corn both provide primarily carbohydrates as energy, but probably do not have the same metabolic effects, particularly when considering over the timescale of a human life. Second, obesity is a symptom. A given symptom may result from multiple underlying conditions. We need to focus the discussion on more specific pathologies than just "obesity".

In the US and many other Westernized countries, one can take a look around and do a "liver check". How many people do you see with a protruding pot belly as opposed to a general body-wide distribution of fat? Most people I see have the big belly, sometimes even being very lean elsewhere (particularly in the arms and legs); there are a few "Rubinesque" figures as well, but the pot bellies seem to be running away with the obesity stakes. The big belly is indicative of fatty liver. Considering how central the liver is in metabolic regulation, it should come as no surprise that an inflamed fatty liver could lead to a whole host of metabolic disturbances: obesity, abnormal lipid profile, elevated blood sugar, elevated insulin, etc. In other words, metabolic syndrome.

I would argue that the rapidly growing health problem is not simply obesity, but metabolic syndrome (remember obesity is only one symptom, and there are thin people with metabolic syndrome too). We want to understand both how we arrive at metabolic syndrome (so our children can avoid it), and also how to treat it for those who did not avoid it. It is clear "carbohydrates" across the board are not causal in the development of metabolic syndrome. Stephan provides several counter-examples; another is the Tarahumara, who like the old-school Pima subsist largely on corn, beans, and squash, but who have one of the lowest rates of Type 2 diabetes in the world.

But the cure is not necessarily the reverse of the cause when it comes to disease. Metabolic syndrome brings a whole host of issues, not the least of which is broken carbohydrate metabolism. So while carbs in general may not lead to metabolic syndrome, once you've arrived dumping carbohydrates on your broken carbohydrate metabolism is tantamount to doing jumping jacks on two broken legs. I believe the science (along with a massive stack of anecdotal evidence) is pretty clear here, in that the most successful treatment for metabolic syndrome is carbohydrate restriction.

So while yes, Virginia, the Kitavans eat a very high-carbohydrate diet and exhibit general metabolic health, for my personal dietary choices I don't really give a crap. The Kitavans have healthy carbohydrate metabolisms, but I don't (prior to going low carb I had a trophy beer gut, which in retrospect was my liver telling me "You're killing me slowly"). If you look down toward your feet and can see only your protruding liver, you might consider trading in the bagels for bacon (better yet, get yourself a blood glucose meter and check your post-bagel blood sugar - it might frighten you). It is important to remember that carbohydrate restriction is successful as a treatment for a disease, but it doesn't necessarily follow that all carbs are bad for everybody. We have several examples of cultures who thrive on diets of lean protein and whole food sources of carbohydrate, like starchy tubers and fruit. We also have examples of cultures thriving largely on protein and fat. Humans appear to have a remarkable ability to survive as omnivores eating whole foods, which in no small part explains why we are one of the most widely spread species on the planet. So if you have a healthy metabolism, you probably can choose from a wide variety of whole foods (and by "whole food" I mean something you could plausibly obtain from Nature without the aid of much more technology than fire and a sharp stick). Once your metabolism is broken, you will likely need to make some choices to avoid those things which, due to your disease state, have become effectively toxic. In other words, make your nutritional choices based on actual knowledge of metabolism and your own state of health rather than picking a buzz-phrase and applying it blindly.

And for God's sake, stop eating wheat ;-)

43 comments:

praguestepchild said...

Great stuff, and glad to see you are still alive and kicking.

I've also been pondering the Taubes/Guyenet false dichotomy. It is an interesting dust up and it managed to pull you and Kurt Harris (at least in comments) back from The Fortress of Solitude, which is always a good thing. My thoughts on the food reward hypothesis are something like my thoughts on string theory. Deeply skeptical. But I know about as much about physics as I know about biochemistry.

Dave said...

@praguestepchild,

Good to be back. I've been bubbling on a couple of posts for awhile, this being one of them. I dearly wish I had been at AHS to serve some this out in person.

Food reward is likely part of the puzzle, as it clearly plays a part in metabolic regulation. I don't think it's the whole thing, but another potential area of malfunction, probably in concert with various other regulatory mechanisms. Successful organisms must have robust metabolic regulation, which generally means a lot of redundancy and intertwining feedback mechanisms.

It also sounded like Stephan is suggesting that metabolic dysfunction is largely isolated in the brain - maybe I'm misreading (low on sleep). That seems backward to me, if you consider how multicellular organisms would have evolved from unicellular (indeed, this is the subject of another post I've been fiddling with). The brain is a pretty late arrival, evolutionarily speaking, while it's addition certainly helps in making overall regulation more robust, I'd be surprised if evolution had it take over the show and simultaneously devolved all of the mechanisms that existed before brains.

What's wrong with string theory? It predicts everything - including everything that isn't observed ;-)

tk said...

Great post. Breaking down the science into common sense. My own carbohydrate metabolism is definitely broken. That I know for sure. I haven't looked down at my feet in a long time. (I hope they're still there!) :)

For me, it doesn't matter if someone finds a group that is able to live to 150 with perfect health on a diet of only white bread and coca-cola. The fact is that I know that won't work for me. (I already tried that diet for years)

Thanks.

Mrs. Ed said...

Great Post. The only one size fits all nutrtional advice I can figure out is that processed foods are bad for everyone. Beyond that it seems that it depends on the individual. I just focus on what works for our family, but I do like reading all the different takes on it. I have started to see more pop up about the role of gut bacteria and nutrition. Also that chemicals in our environment may play with our insulin.

Dave said...

Nice commentary by Dr. Andreas Eenfeldt:

http://www.dietdoctor.com/guyenet-taubes-and-why-low-carb-works

Margaretrc said...

Very sane post! My sentiments exactly. When GCBC came out, I read it and thought "Wait a minute. what about the French? Thai? Greeks? Italians? etc. etc." Now I asked the same thing of Stephan re food reward. It doesn't fit a lot of traditional cultures outside of our own and it only fits our own in recent times, after we moved to a low fat, high carb diet laden with sugar, white flour, and vegetable oils. Hmmm. Whatever role food reward plays, if any, I agree that the underlying problem has to be a metabolism broken by eating a diet that is unbalanced and full of artificial, processed garbage. And that is the problem that has to be addressed. It will be interesting to see if eating bland pap will do it, but personally, I would rather eat LCHF, which both my husband and I do. And eating LCHF did get rid of the liver belly my hubby had, so we are sticking with that.

Dave said...

@Margaretrc

I've been thinking a bit more on this, and I think one point the discussion is missing is the detailed nature of the "carbohydrate hypothesis", in particular necessity vs. sufficiency. Is Taubes claiming that that carbohydrate consumption *will* make you fat (which leads one to "paradoxes"), or that it is a necessary ingredient for obesity? I believe he's pushing necessary instead of sufficient, namely that carbohydrate consumption sets up the hormonal/metabolic environment to promote obesity, but that the actual manifestation may require other factors as well. I feel another blog post coming on...

Anonymous said...

do Kitavans eat breakfast, lunch & dinner?

Looking at nutrient intake per day may be a misleading if we don't take into account meal frequency.

And it's kind of funny that everybody seems to leave aside the idea that the Kitavans could be genetically adapted to their regional natural food supply. What may be valid for them may not apply to europeans or africans because they evolved in a different region. Duh.

Chris said...

I posted a few comments on Dr. Eenfeldt's blog about this (the good Dr's post on Guyenet referenced by Dave), and I think it fits in here.
I think Dr. Eenfeldt's reference to the 'trees for the forest' phenomenon is a good metaphor for Guyenet's argument. I've been mulling it over, and I think I can certainly conceive of a bigger picture that included both insulin-driven, hunger-based food seeking behavior, in tandem with a reward feedback loop that is not unlike the reward response you get with addicitive substances, like cocaine or amphetamines.
Let me just illustrate with my own n=1 observations: I went low-carb back in April of this year, and when I stick to it, I do not get that gnawing empty hunger feeling in the pit of my stomach that I used to get when I would, say, start my day with a blueberry muffin and a cup of coffee with sugar in it. The hunger on a LCHF diet, for me, is mild and far from desperate. I've read the comments of other folks at various blogs who say the same thing.
Now, I would bet that many others who have struggled with their weight in the past have had the 'drug-like' experience that comes along with bingeing on ice cream or cake frosting or some other sugary treat - I mean, I literally would go into a trance-like mental state on such a binge, and engage in almost ritualistic eating. You even stop thinking about or noticing how your stomach feels and instead focus on the taste and texture and the immediate pleasure sensation of putting the spoonfuls of sugar-laden stuff in your mouth. Like others have said (Lustig, Taubes, etc.), sugar is addictive - it is a drug.
So, I see a useful synthesis of Taube's recognition of an insulin-driven, hunger-based carb-seeking behavior, coupled with a reward-system based drive to just eat and eat and eat sugar in its various forms. The insulin traps the fatty acids in the fat cells, the other cells kick into starvation mode, send signals to your brain to go get some carbs, then, especially if you are sucking up the sugar, the reward system response (is it dopamine-based, in your pre-frontal cortex?) kicks in to drive the bingeing.

The insulin response is literally a 'gut feeling'; the 'food reward' response is our dopamine/PFC system kicking in (like those cocaine addicited mice perpetually pressing the lever to get a hit ... until they starve to death).

Dave said...

@Chris,

I'm right there with you. Metabolic regulation must be considered as a whole. Obviously the part that determines what and how much you eat can't be decoupled from the part that handles how energy is used/stored. These two subsystems necessarily communicate, and screwing up one probably throws the other one out of whack as well.

Dave said...

I don't think the Kitavans have had enough to time to undergo significant genetic adaptation. Anyway, I don't think they would have had to. See my point about necessary vs. sufficient above.

Margaretrc said...

Dave, I 100% agree that Taubes is pushing necessary, rather than sufficient, and he said as much in an interview I listened to today: http://audio.5by5.tv/broadcasts/paleo/2011/paleo-030.mp3 And I agree with both of you that, whatever the reasons for metabolic breakdown, it is carbohydrate restriction that is the key to a return to health. Not undoing the damage--I don't know if that can be done--but a return to normal weight, heart health and non-diabetic BG numbers.

Anonymous said...

Food reward. This confuses me. I am reading a book about African cultures, how they stew meat for days and days with spices, eat it with whatever they have access too (presumably pulses, grains, animal fat, etc). Now this is all whole food by your standards (okay, maybe not the grains--depends on prep I guess) but this all sounds pretty dang tasty and rewarding to me and I could eat and enjoy LOTS of it. And I could think of other wholesome food cultures where, yes, the food is not processed, but where they ate carbs and fat together to no metabolic demise. So I guess my question, perhaps more for Stephan than for you, is why are we making this food reward thing out to be such a novel 21st century concept? People had carbs and fat together in a pleasure-inducing recipe combination since forever ago! This is not new! Is it because they didn't have everlasting access to those combinations? Seasonality, drought, governments taking away ingredients??

Would love your insight.

Thanks in advance!

~Discombobulated

Dave said...

Isolating food reward tends to lead to circular arguments. Food reward is a learned response, your body's way of figuring out what's good to eat, and making you eat more of that. Say you try some round red things hanging off a bush. They taste sweet, which registers in the primary taste cortex. The process of digestion causes a variety of signals to be detected and integrated by the secondary taste cortex. These include things like glucose and insulin, along with other hormones, and probably micronutrients as well. The secondary taste cortex deems this a good thing, and the next time you see round red things on a bush, you'll have the urge to eat them. On the other hand, if they give you a stomach-ache, that behavior is downgraded.

But I don't think you can say "eating rewarding foods leads to hedonic dysregulation" or something like that. That basically boils down to "eating rewarding foods leads to eating rewarding foods", to which I would respond "no shit". What made it so rewarding in the first place? We're not born loving wheat, we learn it from the biological feedback created by eating wheat.

My point is that food reward is necessarily integrated as part of metabolic regulation, both short and long term. Try eating a whole stick of butter, or 20 pieces of bacon. Starts off very rewarding, but will stop tasting good after awhile. So I think the question isn't whether it's insulin (or leptin or whatever) vs. food reward, but why/how the connection between them gets broken.

Jane said...

Hi Dave, remember me? Good to see you back, and talking your usual good sense. With one tiny exception, perhaps. Wheat-bashing is SO last year ...

Dave said...

Hi Jane. Actually, with publication of William Davis' "Wheat Belly", I would think wheat bashing is very much this year. ;-)

It comes down to the cost-benefit analysis. Wheat might be harmless, or maybe not. The potential downside is fairly large. We have to emphasize "potential", but there certainly exists a significant fraction of the population (e.g. celiac sufferers) for which the downside is definite and painful. And the potential upside? Not much, and certainly nothing not easily obtained by substituting other foods. So why risk it?

Jane said...

Thanks, I hadn't seen Wheat Belly. Would I be right in thinking that the bad stuff all relates to white wheat flour? - which I agree is so toxic it shouldn't even be called food.

But you're right, why risk it? If you've been brought up on white flour, you will have been sensitised to gluten and probably can never tolerate it.

I must say in wheat's defense, though, that the evidence suggests that if you've always eaten only whole wheat, it's a good food. Those ancient Egyptians apparently ate white flour, as rich people though the ages have done.

Dave said...

"Wheat Belly" argues that wheat is bad across the board, white, whole, or whatever. Still not a lot of slam-dunk science here, but certainly many bits of evidence that all point in the same direction. Contains an interesting discussion of how modern "wheat" (dwarf varieties introduced in the 1980's) has significant genetic differences from the "ancient" wheat that drove the development of agriculture.

How can gluten be bad in white flour but not in whole wheat flour?

Jane said...

Because the proper handling of gluten needs micronutrients that are removed from white flour.

Gluten is not really a toxin, it's the plant's way of storing amino acids. When the grain germinates, gluten is broken down by enzymes that have counterparts in our own digestive systems, and require cofactors such as magnesium or manganese, which are almost completely removed from white flour.

These metals are also needed by the gut immune system, which is normally instructed in a process called oral tolerance not to react to dietary proteins such as gluten. It's the failure of oral tolerance that causes celiac disease.

Dave said...

@Jane,

Which enzymes? Do you have a reference showing this in humans?

I don't see how the function of gluten for a plant is related to it's toxicity in humans. Cholesterol isn't a "toxin" per se, but is definitely toxic for rabbits.

Here's they celiac hypothesis put forward in Wheat Belly (also the reference 24 pasted below):

Regulating intestinal permeability is therefore a fundamental function of the cells lining the fragile intestinal wall. Recent research has fingered wheat gliadin as a trigger of intestinal release of a protein called zonulin, a regulator of intestinal permeability.24 Zonulins have the peculiar effect of disassembling tight junctions, the normally secure barrier between intestinal cells. When gliadin triggers zonulin release, intestinal tight junctions are disrupted, and unwanted proteins such as gliadin and other wheat protein fractions gain entry to the bloodstream. Immune-activating lymphocytes, such as T-cells, are then triggered to begin an inflammatory process against various “self” proteins, thus initiating wheat gluten- and gliadin-initiated conditions such as celiac disease, thyroid disease, joint diseases, and asthma. Gliadin wheat proteins are akin to being able to pick the lock on any door, allowing unwanted intruders to gain entry into places they don’t belong.

Davis, William (2011). Wheat Belly: Lose the Wheat, Lose the Weight, and Find Your Path Back to Health (Kindle Locations 1289-1296). Rodale. Kindle Edition.

24. Drago S, El Asmar R, Di Pierro M et al. Gliadin, zonulin and gut permeability: effects on celiac and nonceliac intestinal mucosa and intestinal cell lines. Scand J Gastroenterol 2006;41:408-19.

Jane said...

Have a look at 'The activation of intestinal peptidases by manganese', which is very short and says 'Since the intestinal enzymes that hydrolyse other peptides such as glycylglycine and prolylglycine are also activated by Mn, it becomes clear that there are in intestinal mucosa several metal-containing proteases.' The prolylglycine is important because peptide bonds involving proline are difficult to break, and there are lots of them in gluten.

You could also try 'Metal activation of peptidases', or 'Alterations of pancreatic digestive enzyme content in the manganese-deficient rat'. I don't know of any paper addressing these questions specifically in humans.

Some gluten breakdown occurs intracellularly in lysosomes, several of whose enzymes including the proton pump are glycosylated, which requires manganese. Manganese and magnesium activate the enzyme that makes glutamine, which is used as fuel by enterocytes. Everywhere you look, there are digestive processes dependent on these metals.

About intestinal permeability. Gluten needs to open tight junctions to gain access to the gut immune system for establishment of oral tolerance. I had a quote about this from a textbook that I sent to some people and will try to find.

Jane said...

Here it is:

Normally, a state of oral tolerance exists for gluten. In persons who do not have celiac disease, the peptide products of gluten digestion by pancreatic and brush border enzymes traverse the apical membrane into the enterocyte, where they are further processed by hydrolases to nonimmunogenic products. A tiny fraction of undigested gluten enters the lamina propria through tight junctions and generates oral tolerance. ...

Anonymous said...

WOW, Thank you for a sane sensible blog post. It's the best one I have read in quite a while.

montmorency said...

While the the phrase "great stuff" would apply to this and all of your posts Dave, I'm not sure it really applies to Stephan's IMHO.


After supposedly deconstructing Taubes' major theses, even while admitting that low-carbing works for "some people" (I would say it works for everyone who tries it properly, but it may only work to a limited degree for quite a few of us), when at the end he is trying to describe how it works, he has to fall back on the old story "it works by reducing calories".


Ah, so it was CICO all along! And I thought it was all so much more complicated, including leptin, ghrelin, other things ending in "-in", or "-ides", and lots of other things with ellipses in their names. Thank you for that insight Stephan.

And I thought it was Taubes who was suppposed to be over-simplifying.


What Stephan has failed to explain is why I and many other carbers, even if we haven't all quite got down to the 30-inch waists that we had as 20-year-olds, can reduce our calories (if that is indeed what we are doing) on a low-carb diet, without experiencing hunger in-between meals (even on only 2 meals a day for example, and without any form of snacking)?


Gary Taubes would (I think) say that it's because of the newly liberated free-fatty-acids which are now available to supplement our now-reduced calorie intake.


However, in what Stephan has written, he has eliminated that as a possibility (if you go along with him), but not put anything in its place. Non satis

Calorie Counter App said...

WOW, Thank you for a sane sensible blog post. It's the best one I have read in quite a while.
Thanks for sharing with us.

Johman said...

Amen to this post! In our society many are metabolically broken, perhaps from babyhood and have had constant exposure to processed foods. So what do we have in common with those primitive carb cultures metabolically? Not much.
I'm tired of seeing "experts" putting obesity as the cause of the myriad of health problems that follow, rather than a symptom. That leads them to think that whatever skinnies up a person is healthy (bariatric surgery,anyone?).

montmorency said...

Dave,

I hope you are going to post in 2012. I've been missing the Sparks of Reason, and I'm sure I'm not the only one.

How about this to provoke you?:

http://wholehealthsource.blogspot.com/2011/11/brief-response-to-taubess-food-rewad.html#more


Regards,
Mike

Dave said...

Thanks - lots of ideas, too little time. Been really busy lately, haven't even had a chance to read any of Taubes' replies to the initial argument.

Olga said...

Hi Dave:
Could iodine be part of the reason some primitive societies tolerate carbohydrates so well? All the societies mentioned by Stephan Guyenet who eat primarily carbohydrates successfully live near the ocean. The Kitavan's, the Tokelauan's, the Okinawa. Perhpas they can eat carbohydrates, because they have healthy thyroids over their life times. The average Japanese consume about 12 mg of iodine per day. Far more than the RDI of 150 ug. It has been argued that 150 ug is merely the amount of iodine required to prevent goitre and that our actual needs are far greater for optimal health.

Is it possible that the reason some people claim to experience a decrease in thyroid function when on a low carb diet, is because a low carb diet unmasks an iodine deficiency?

Jack C said...

Dave, In a 2010 post on the whole health website you discussed a problem that your infant son had with a caries.

An internet friend from Montana has an infant son with several caries. She has been giving vitamin D and K2 but the caries have not healed. She is looking for advice if you have any to offer.

Jack C. @ jandpc@bellsouth.net

Anonymous said...

Dave,
I was looking at a comment that you made about tooth-recalification. My son has some "soft spots" that I would like to heal rather than fill. I would love to hear your experience. della.chad.spam@comcast.net
Thanks.
Della

George Henderson said...

@ jack, retinol is also required for remineralisation of teeth. I also suggest eating hard cheeses before bed.

This is the best post I've read on this debate.

Food reward is pseudo-scientific mysticism unless palatability is objectively measurable.
A theory of addiction, mediated by exorphins and neurotransmitter modulators (MSG, fructose, etc) at least has the benefit of a measurable mechanism.

Reggie Dixon said...

I'm 47, Caucasian, Male, 6'3" and I have known for a long time that I eat a higher percentage of Carbohydrates in my diet than these Kitavans I had previously not heard of. I'm sure nobody "gives a crap" but I weigh 175 and have a 27" waist (as measured by a health professional). I know in advance the kind of adverse comments I am going to receive but my point is this. I would be willing to bet that I am absolutely the same in terms of internal chemistry as anyone else. There is a simple reason I am the weight I am, every morning I step on the scales, if the number is higher than the day before, I eat a little less, if it is lower I eat a little more.

Dave said...

@Reggie,

And yet, animals, when eating the diet they evolved to eat, manage to avoid being overweight without scales or the ability to reason about the consequences of what they consume. Humans have obviously evolved to be special, where over the course of several million years our genes amazingly mutated such that the invention of the scale would save us from obesity.

Reggie Dixon said...

Sorry Dave, I should have been clearer that the scales were a device, I could equally have said that if I have overindulged one day I eat less the next. I have competitive (sporting) reasons for monitoring my weight.

Dave said...

@Reggie,

Your internal biochemistry may be intrinsically the same as everyone else. But if you're a competitive athlete, the net result of that biochemistry is certainly different, since you are putting much different demands on your body. For instance, now that I've started training in power-lifting, I have to eat more carbohydrates to maintain muscle glycogen. Otherwise I literally run out of gas. The body is not a closed system, and the context in which it operates makes a big difference in the final outcome of its interactions with the environment.

Interesting article, tangentially related:

http://roarofwolverine.com/archives/1437

David said...

Hello Dave,

My name is David Haskell - I am a co-producer on the new documentary "In Defense of Fat: Rethinking the Bad Science Eating at America's Health." The film is about obesity, health and the politics of nutrition, introducing the principles behind ancestral health and the paleo diet and encouraging a change in the way the culture talks about obesity.

The film talks about this very issue and we would love to tell you more about. Please feel welcome to contact me at davidi.haskell@gmail.com.

Thanks and keep up the great blogging.

David

George Henderson said...

Not only in Kitava (et in Kitava ego?) but in pre-famine ireland, where the potato had supplanted wheat and buttermilk and spuds was the stable diet of the poor - who thrived on it while it lasted.
Ireland on the potato, despite the worst poverty in Europe, had double the population growth rate of England and Wales on bread, and supplied most of the soldiers for the British army.

http://www.dochara.com/the-irish/food-history/food-in-ireland-1600-1835/

Dave said...

@George,

Interesting point, however I would counter that that reproductive success and "health" defined as quality-of-life don't seem to be closely related. The world is full of examples of individuals who created multiple children and dropped dead by 40.

The Other Jane said...

And as adjunct to the iodine comment... Broda Barnes' book "Hypothyroidism The Unsuspected Illness" describes "sluggish liver function" that sounds a lot like fatty liver.

I think metabolic syndrome is another word for low thyroid function. And no, a blood test does not diagnose it correctly, doctors today have forgetten how to look at a patient and diagnosis it clinically. Read Barnes and Stephen Langer and Mark Starr's books on the thyroid. Very interesting information on low thyroid, carb tolerance and the pancreas and insulin as well.

Dr. Dan Egan said...

Obesity, like heart disease, results from a complex interplay of factors, some of them known, many of them not. Laying the blame for obesity at the feet of "too many carbs" is akin to blaming heart disease on high cholesterol. No doubt these each play a role, they're necessary but are insufficient to explain the entire phenomenon.

Low carb does wonders for many people (myself included), but metabolism is a complex dance of hormones, circadian rhythms, and epigenetic signalling. Low-carb is a great starting place for most Westerners, but could be akin to using a hammer when a scalpel is what is really needed.

I'm new to your blog, but shall return. Anyone that can use the words "trophy" and "beer gut" in the same sentence, is worth following.

George Henderson said...

Yes, true enough Dave; it was the Irish being fit enough to outsoldier the rest of the Brits that spoke to the soundness of their constitutions.

I have a theory that might fit the corn vs wheat or potato vs wheat differential; B vitamin status.
With modern fortification explaining much.
Not an original theory but I think I'm the first to single out thiamine.
http://hopefulgeranium.blogspot.co.nz/2012/08/the-role-of-vitamin-fortification-in.html

Danny Albers said...

@George

Explosive population growth followed the introduction of grain harvesting and in fact any form of high yield agricultural carbohydrate sources in general.

As we know, most of the negative effects from a life long diet of wheat start to show up in many people after we have had kids.

But if we pick and choose famine studies, Iceland had a recent 600 year period of pretty much zero carb as a country from 1200 to 1800 AD and the fossil record shows they were one of the healthiest groups ever.

Humans above all are adaptivores but I think our modern diet has pushed us past our rate of adaptation.

When we thought we could make butter and cream better than cows, we were already doomed.