Whoa, did I have an a ha moment today!
Remember, just last week I’d explained why I eat moderate carb. I’ve been on ketogenic diets (i.e., in ketosis) in the past, but have struggled to stay on them for more than a few months at a time.
So when Kurt Harris talked about ketosis and hormesis on Robb Wolf’s Paleo Solution podcast today, I was just gobsmacked. Talk about your critical puzzle piece!
[Tip: if you're not familiar with hormesis, check out this page from Todd Becker to get a quick intro. Basically, the idea is that exposure to a little of something causes our body to respond in a way that can be healthful for us (e.g., vaccinations), while a lot of exposure can be harmful.]
If you want to take a listen, check out the podcast (link above) starting at the 30:53 mark. But I’ve gone ahead and transcribed it for your reading pleasure (I’ve made only minor edits for readability’s sake):
Robb: Joe says, “I have a question concerning your last post on your blog (which was back in February). I’ve always been under the impression that the brain could run efficiently on ketones, but in your post on carbohydrates you unequivocally state that glucose is necessary for optimal brain function. Am I mistaken in my belief that you do believe that ketosis is dangerous for brain function? How would you situate ketone bodies in your classification of fuel?”
KGH: The thing to know is that the brain requires glucose in an obligate fashion: meaning it’s not an option. The brain has to have glucose. Where ketones come in is that, instead of having it be all glucose you can substitute — I don’t know what the number is, 50 or 60 percent let’s say — of the energy requirement can be made up of ketones. That’s an adaptive response to starvation. To the degree that being on a very low carbohydrate diet or constant ketosis all the time … I’m going to take a tangent here that doesn’t directly answer the question. …
We just got done talking about hormesis. This answers the question when people say “Why don’t you think you should be in ketosis all the time? If ketosis is good for you, why shouldn’t you stay on a ketogenic diet?” Because it’s hormesis.
It’s hormetic to be in ketosis. It’s probably hormetic to do intermittent fasting, it’s probably hormetic to have reduced meal frequency or go 16 or 18 hours every day without a meal versus snacking. That’s probably hormetic. Taken to extreme, it’s called Auschwitz. It’s called starvation. That’s the extreme of not eating.
In the same sense, I think ketosis is good for us to do once in a while. It’s something that naturally occurred during our evolution occasionally. I don’t buy the thrifty gene hypothesis, but periods without food were not that unusual, so it’s logical that that might be good for us. But staying in ketosis all the time is not good for us just because some ketosis is good for us.
For me, this neatly fits with what I briefly mentioned in my previous post: the value in cycling carbs seasonally. What could be more natural from an evolutionary perspective?
What the heck does this have to do with bisexuality?
Well, I’ve been thinking recently how taking a moderate position on carbs is like being bi — it can be hard to be “out” about it, as it’s a polarizing issue and frankly, folks push you to take a side.
I’ve been thinking about the parallels recently because one of my political reads pointed to a recent study showing bisexual men exist (trust me, I’ll get to the point soon):
Despite enormous strides made in the past decade for LGBT rights, male bisexuality remains a challenging idea and a unique taboo, even within sexually progressive circles.
A large part of that is because, culturally, we tend to think in terms of black-and-white, not shades of gray — and that’s especially true when it comes to the subject of sex. Rarely does a bisexual come out without fielding questions about which sex they like more — the assumption being that they must lean one way or the other.
So really, no matter where you are on Kinsey’s scale, consider the similarities to the current discussion of macronutrients in the blogosphere and elsewhere. If you want to turn up the heat, just get into a discussion about the idea macronutrient composition of a healthy diet — and try and argue a middle position.
Like the LGBT community, the LC community have their identity pretty staked out. So just as the bisexual man is a “challenging idea” so too apparently is the idea of more moderate carb consumption.
Exhibit A
Funnily enough, Dr. Mike Eades (of Protein Power fame) provided one such example today on Twitter in a conversation with Chris Kresser. Here’s a snippet (edited slightly for readability):
Dr Eades: Carbs in the diets of most hunter-gatherer societies were markedly different (lower) than amounts currently recommended http://t.co/opWgWZg
Chris Kresser: That study also said “diets of hunter-gatherers showed substantial variation in their carbohydrate content”. From 15-35%.
Dr Eades: The paper doesn’t give us a clue about carb tolerance; it merely states what the various groups consumed.
Chris Kresser: Modern HG have low rates of CHD, obesity, inflammatory disease, so we can assume they tolerate up to 35% natural CHO fairly well.
Dr Eades: Remember Bastiat’s parable? You’re falling victim to That Which Is Seen. You know nothing about That Which Is Not Seen.
The last point is one that Dr. Eades made in his AHS11 presentation: according to Eades, just because some groups appear to tolerate carbs doesn’t mean that they wouldn’t do better without them.
Well I suppose. However, to me, this just doesn’t fly given what we know about evolution or physiology.
If you listen to the podcast, Kurt goes on to answer the question about ketones and the brain. While part of the brain does quite well on ketones, it still requires some glucose. So ketosis is an adaptation that enables the brain to preserve glucose stores — the body’s lean body mass — in a time of starvation.
For me, ketosis as hormesis makes sense. Eat sufficient carbs (Paul Jaminet suggests 400-600 calories, which is interestingly, Mark Sisson’s “effortless weight maintenance” range) most of the time with some low and high carb periods for variety.
Works for me!
Weight Maven is written by Beth Mazur. Beth believes that obesity is more symptom than cause and that the real problem is our Western diet -- especially sugar, refined grains, and industrial oils. Beth writes about nutrition, ancestral health & food policy. And cats! 
Beth, I’m so glad you chose these 2 part-conversations to blog about. I’m still listening to the podcast, but have been struck by the non-precious-ness (is that even a word?) of both Robb and Kurt. They are talking about what works, what feels right and good, and what makes sense. I love it! If you apply the concept of hormesis across many of the ‘healthy’ lifestyle guidelines in the paleo world you start to get something that sounds very much like common sense. Ketosis is great - sometimes. VLC/LC/ModC are all also great - sometimes. Working out to exhaustion is great - sometimes. Meandering along a country path is the exception - it’s almost always great!! Perhaps you need to expand on your version of paleo . . . bi-paleo? Bi-Pal? Or, given the libido lifting properties of moderate carb - sexy-pal? Or run it all together and coin the term “bisepal” or BSP?
Thanks Jacquie! Re terms, I don’t think I want to go that far ;). Frankly, if pushed, any comparisons really break down quickly. Also I didn’t even mention it, but I too was struck by the shifting of positions away from hard edges. Kurt saying that legumes weren’t so bad? Robb eating butter? What’s next? Human sacrifice, dogs and cats living together… mass hysteria :)
Also glad to see that Kurt (and Chris Kresser) have convinced Robb to stop recommending mega supplements of fish oil, even for a short time. Taking 1g/10lbs of body weight always seemed nuts to me.
The debate about how many carbs are necessary reminds me of a stanza in Marat/Sade:
“We invented the Revolution
but we don’t know how to run it
Look everyone wants to keep something from the past
a souvenir of the old regime
This man decides to keep a painting
This one keeps his mistress
He [pointing] keeps his garden
He [pointing] keeps his estate
He keeps his country house
He keeps his factories
This man couldn’t part with his shipyards
This one kept his army
and that one keeps his king”!
There is no doubt that some people tolerate carbs more than others - the young and fit especially. Personally I don’t tolerate many at all. Perhaps it’s because I actually did the ‘heart-healthy’ diet of high carb/low fat (all complex and whole — no white flour, sugar for me) for over 3 years and gained 50 pounds! Probably broke my metabolism for carbs or something. I did it because when I started graduate school in nutrition it was considered the best diet to prevent heart disease (runs in my family as does diabetes) - but I have never felt worse in my life - was depressed too. The best book on this is Volek’s and Phinney’s book “The Art and Science of Low Carbohydrate Living.” I like their concept of carb tolerance.
One could probably turn the hormesis argument around and say that having carbs is the occasional event. Think seasons — and climate. Bruce Fagan in his book Cro-Magnon argues forcefully that it was the ice-age that made us modern humans and we lived for tens of thousands of years with no more that one cupful of plant food a year in Europe. He makes it plain that fat was our primary food. All the glucose one needs the body can make itself. I’ve always been struck by how that body goes into over-drive to get blood glucose down — just like it deals with alcohol. Spencer Wells in his book “Pandora’s Seed” has a revealing chart illustrating the superior health of our stone age ancestors even when compared to contemporary humans (both pelvic inlet index and height were greater). I wish I could attach pdfs - I have so many articles that detail the benefits of ketosis. And I like what carb restriction has done for my lipid profile - TGs way down, HDL way up, low fasting glucose (in the low 80s), pattern A LDL and I am rarely sick — not bad for a soon to be 63 year old. And yes I’ve lost some weight too.
Even Orangutans do it - they burn down their fat in the non-fruiting seasons and excrete ketones.There are distinct fruiting and flowering seasons - and that is now, not the dry ice age conditions of the tropics. Gorillas too. They eat fruit in season and leaves and bark (more protein) in the non-fruiting seasons. http://resources.metapress.com/pdf-preview.axd?code=m177r72644ptj238&size=largest
Just a few thoughts - time to move on.
Elizabeth, there’s no doubt that there’s wide individual variation in nutrition in many things, not just carb tolerance. Because of my concerns of long-term carbing (particularly with regard to the thryoid), I’m working to restore my insulin sensitivity (via diet and exercise) and avoiding high carb intake. So far, I too have low TGs, high HDL, and low fasting glucose. And I hit the 100-lb weight loss mark last month. Not bad for someone in their 50s either ;).
I was going to have my LDL type looked at, but am rethinking it after listening to Chris Masterjohn on Chris Kresser’s podcast. Sounds like the current state of lipoprotein particle size tests leaves a little to be desired re standards, comparisons, etc.
Way to go! Sounds like you too are doing well with your carb restriction. I lost most of the 50 pounds I gained on the high carb diet — I didn’t go on the diet to lose weight — my weight was fine at the beginning of my ‘heart-healthy’ diet. I’ve gained some weight back — on 4 brief, separate occasions when I was traveling and splurged on some wheat and potatoes — not that many calories but enough carb calories for my fat cells to upload. Unfortunately it wasn’t water weight — it’s real. I certainly didn’t eat an additional 3500 calories for every pound I gained either. My post menopausal body can literally gain over-night — I know so many women who experience the same thing. Mother nature lets us live after our reproductive capacity is over — but I’m not sure if she wants us to eat - or at least not very much. Now I tend to eat for protein and accept whatever fat calories come along with it.
I ate a high fat (low PUFA)/low carb/moderate protein “Paleo” diet during my big weight loss extravaganza, and the only complaint about eating <30 carbs a day was the tired feeling.
As for the brain needing glucose, isn't it about 12 tablespoons of glucose it needs? I remember that figure from something.
I agree with Kresser on this, carbs aren't the only problem in our diet right now- there's PUFAs, hydrogenated oils, excitotoxins, you name it. Blaming the USDA's food pyramid for the obesity epidemic is quite reductionist as current hunter-gatherers eat their fair share of carbs and aren't having the problems the rest of the world is having (not to mention that there are other populations minus H-G's who eat just as high if not higher carb intakes).
From what I’ve read, the brain typically accounts for about 20% of energy needs, so the ballpark math for a 2000 calorie energy TDEE would be about 400 cals worth of glucose or 100g or 25t or 8T. Those are clearly rough (not sure if glucose and sucrose share the same g/t equivalence) and the actual number would presumably vary depending on many factors … 12T could well be a good figure.
I’ve also read that once you’ve become keto-adapted, ketones can substitute for 70% of this. The rest would come from either dietary protein or in the absence of that, lean body mass.
Botox, ethanol, caffeine, adipose tissue, just about every medication that exists, has something of a bell curve. None may not be ideal (with the exception of botox), a certain amount is healthy or therapeutic, too much is toxic.
Julie, thanks for the comment. I certainly find the idea of hormesis intriguing (in fact, there was a discussion a while back about whether or not the benefits of fruits and veggies were via hormesis). But I hadn’t ever considered that this principle might apply to ketosis. Thought it very interesting!