The Essential Carbohydrate?

I would ask each and every reader to try as best you can to check their nutritional biases at the door here as best you can  and let's just talk semantics.  

What does essential mean?  

Something that is essential is something that we cannot do (or in the nutritional context live) without.  By this definition, it is clear that yes, for most humans, carbohydrates are non essential.  However, even this is too simplistic, because without looking very far, we can identify a group of humans for whom carbohydrates are "deadly" essential.  As in imminent death kind of essential.  Relatively rare as is their number, I'm talking about people with glycogen storage/breakdown disorders.

Now, let's look at the other macronutrients.  Well, we cannot live without protein.  Therefore it is essential.  No argument.   However, proteins are comprised of 21 distinct building block amino acids of which only 8 are actually identified as *essential*.  A strict interpretation of this fact might be that ... eh ... 13 amino acids, or the majority are non-essential.  We don't need them.  They can be made by the body from other stuff.

Lastly let's look at fats.  There are only two technically essential fatty acids.  Yep! A measely two out of tens perhaps hundreds of fatty acids of varying chain lengths and degrees of saturation -- that are essential.   That number can be increased slightly to include but three more "conditionally essential" FA's although theoretically these can be derived from other compounds.  But let's stretch it to say that those other compounds are usually not present in sufficient quantities, so we have a need for five fatty acids.  That's still a small portion of all fats.     Notably absent from the essential list?  Long chain saturated fatty acids, e.g. palmitic acid.

See where I'm going here?

If we're going to define essential as necessary to sustain life, humans can apparently survive on an emulsion of 8 amino acids and 5 fatty acids -- and I suppose we'd have to include vitamins and minerals etc.   

Perhaps Stephan's onto something with that bland liquid diet from a straw study in his Food Reward series over at his blog.  If we can create a liquid concoction of all these essentials we could solve malnutrition and obesity in one swoop!  

Non Essential = Potentially Toxic in Excess:

The flipside of the "essential" argument coin seems to me to be that because we don't need carbs we are somehow predisposed to toxic effects of consuming them in excess.  Let's look at a benefit/detriment balance then of the three macros.  

Here things shake out rather worse for the "essential" macronutrients than for the beleaguered carbohydrate.  How so?  Well, the worst thing a carb ever did was cause some transient hyperglycemia.  Granted down the line a chronic state causes issues, but sugar and starch are not potent *poisons*.  Chronic hyperglycemia is due to unrestrained gluconeogenesis in the end.  But even if totally from dietary sources, the toxic effects are long term and far more detrimental things are going on due to the underlying disrupted metabolism.

In this regard, I'm also willing to give a pass to omega 6 fatty acids.  Their disease-agent qualities -- whatever they may be -- are still thought to be more long acting in nature, although some do seem to attach potential drug-like qualities to these.  

Now the essential AA's are another story!  We have phenylketonurics for whom even normal amounts of this essential amino acid poses a toxic threat.  Another essential AA, leucine, is associated with pellagra.  

My point?  An argument based on excesses for the macros is irrelevant to the discussion on whether or not they are essential.

Essential v. Optimal:

There is no doubt that glucose is essential to sustain human life.  But because we can produce glucose from non-carbohydrate substrates (amino acids), the rationale is that we don't have to consume glucose.  True.

But do we *need* long-chain saturated fats then?  It would seem not, because our bodies are more than capable of synthesizing saturated fatty acid from carbohydrate by de novo lipogenesis.   By the logic above, we don't need to consume any saturated fats because we're more than capable of making our own.  

So I'm going to go out on a Clintonesque limb here and say that it sort of depends on the meaning of the word "essential".  Or more broadly the context.  Essential for what, exactly?  Just life?  Because it is true:   We die without protein.  We die without fat.  We live without carbs.  So if I'm stuck on a desert island and a genie grants me only two macronutrients I'm picking protein and fat.  But that's sort of a silly scenario to contemplate, no?  

Rather than what is essential, the more relevant argument/discussion should be "what is essential for optimal life".  We're often told that the O3's in flax are inferior to those in fish oil, because although we can convert them to the forms most beneficially utilized by humans, we're not particularly good at doing this.  Similarly we should ask whether just because the body can make all the glucose it needs, whether that is optimal as a source vs. exogenous sources.

Another way is a bit more physiologically minded.  Though carbs may not be essential, they do play a crucial role in metabolism.  Despite the demonized glycation seen as universally negative, glycosylation is the normal process that activates/deactivates certain enzymes etc.  Rather than the body having to scavenge and conserve and produce glucose for essential life-sustaining functions, I believe a case can be made that it is more optimal to supply the body with at least some of its glucose *needs* directly.  

This boils down to the genie on the desert island offering me up two whole foods to pick from rather than the macros.  I'm picking salmon and potatoes.   Such a diet would serve my body better.

Immediate v. Long Term Needs

The last argument I'll present with regards to the essential nature of dietary carbs is that of the immediate need vs. the long term need.  In a normal human, there is never an immediate need or short-term need (a few to several days) for any of the three macros.   In the longer haul, the most essential of the three macros appears to be protein.  

And yet for persons with metabolic disorders, it is only the carbs that pose the possibility of immediate danger of the ultimate lack of essential nutrients -- aka death --  if hypoglycemia develops and severely enough.

To Sum Up ...

So putting it all together, where does this leave us?  I am of the opinion that the "you don't need carbohydrates" mantra of the L.Ron Hubbard of the Latter Day Church of MAD*, R. David Feinman, is the  most meaningless argument in favor of carbohydrate restriction for weight loss or otherwise.  Optimal human nutrition for longevity and performance inarguably includes considerable dietary carbohydrates over the centuries.

*church named by Anthony Colpo.


Anonymous said…
'If we're going to define essential as necessary to sustain life, humans can apparently survive on an emulsion of 8 amino acids and 5 fatty acids -- and I suppose we'd have to include vitamins and minerals etc.'

Do we really need vitamins and minerals? Just asking. If we do, do meats and fats provide them all? Do they need to to provide them, are there some we could live without (would we want to?)

What happens on an only meat+fat diet (minus some vitamins and minerals)? Does anyone live on such a diet - that we can actually verify today?

I have a serious addiction to vitamin and mineral supplements (serious because I can't seem to give them up!) - which only got worse when I spent time low-carbing.

It did seem to me that support groups for low-carbers do talk a lot about supplements.
LeonRover said…
For me the genie would supply eggs and spuds

BUT I would also BEG for a soupcon of onion!

CarbSane said…
Hey Leon! Long time no see :-)

@Euler, you raise a very good point. While it may be possible to get them all in meat and fat (something I doubt) in the manner in which it is envisioned paleo man ate animals (organs and such) ... present day paleos and low carbers don't get even that. You are right about the supplement culture in low carb circles. Not saying they're all bad or wrong but if one is supplementing consider that it's missing in the diet. It may be modern foods and lifestyles require such, but those same "modern foods" were around in the 60's and 70's and we seemed to do just fine then.

Every time they isolate something from a food to supplement it seems the effect is still different than the whole food. I'm always reminding myself as well that just because it's natural doesn't make it safe at every dose (hemlock is natural!) and some of these things taken at concentrated acute doses could be potentially harmful down the road.
Anonymous said…
Present day paleos do things like live on eggs, meat and froyo and call themselves 'carnivores'.

Not data driven, but the seafood several times a week probably offers some compensating effects for the lack of green stuff that isn't lime for vodkas.
Anonymous said…
Hi Carb Sane
I've been reading your blog for a while but haven't been able to work out how to comment until now.

You're addressing a very important issue in this blog post and I think Kurt Harris has a very good way of putting it.

"It is a fact that we do not require glucose in the diet, and that we can make it from amino acids if we don't eat it. However, rather than viewing this as evidence that glucose is not important, we should view this as evidence that glucose is so metabolically important that we have evolved way to make sure we always have it."
Diana said…

Wow, for once Kurt Harris says something I can wholeheartedly agree with, because I've said it myself, somewhere or other.

Another way to put it would be, why go to all the trouble of forcing your body to create glucose, when you can just eat some?


You know how much I truly love and respect Richard Feinman (not Richard Feynman), but just this once, I have to ask the guy to perform a thought experiment.

Imagine you are a human being, 50K years ago. Think of just how brutally tough your existence would be. Think of how uncertain food supplies are. Think of just how hard, hard, hard, it is to obtain calories.

Think about it.

I have a thought experiment of my own.

Do you think that the obsession with the Paleolithic era, hunting, proteins and fats, and the "dissing" of carbs as inessential, is a psychological way of dismissing the importance of (female) gathering in the Paleolithic lifestyle?

I'm going to say it is. I think the vast majority of the "Paleo" movement is made up of a bunch of latter day nerds, who couldn't throw a spear accurately if their lives depended on it, and who have huge masculinity issues.

I realize that the CarbSane Asylum is a place for rational scientific discussion, but I had to get that offa my chest.

I think that a lot of what the "Paleo" crowd says is a bunch of entertaining just-so stories. Modern life kind of sucks to them, so they've got to make up a lot of myths about the past.
Archibald said…

With this post you may have answered a question that I have been wanting to ask but couldn't find the right context in which to do so, but I would certainly appreciate any further comments that you would be willing to make. To wit: given that some essential fat is an absolute minimum, when, otherwise, might low-fat become too-low-fat?

Over the past year I find myself eating greater and greater amounts of starch with fat going in the opposite direction, and I wonder where I should draw the line at least from a health standpoint if not a behavioral one. Believe me, it's nothing even close to extreme at this point, and I'm never ever throwing out another egg yolk or tweezing fat flecks off skinless chicken breasts! I just use little to no added fat, have a boiled egg rather than a fried one, and do a lot of trimming and draining of fat from meats and broths. Yet I get very conflicted now when I read the blogs of people, thoughtful ones, not the zealots, who think that >=50% fat is arguably better than <=25% (or whatever). In addition, while far from diabetic, I certainly am IR and get a bit nervous as I see my BG numbers responding accordingly to the carbs (and protein?) in a way they don't with more fat, less CHO, especially when I allow myself to read over at Dr. Davis's site and even Jenny's (Yeah, I know, "then don't do it!") Weight control is, by far, the biggest (!) consideration for me, and I do enjoy the greater freedom from meticulous portion control that I realize from a LF, possibly VLF WOE.

So, Abby -- I just started feeling like I was writing a Dear Abby letter -- do you think that it's simply a personal choice based on issues such as preference and what's best for weight or behavioral control, or would you include other considerations like nutrient absorption, etc. etc?

Confused in Kalamazoo!


P.S. @Diana. Whew! I'm almost nervous to even have my comment land right below yours, but, even though I may have masculinity issues, at least I'm far from Paleo, so I'll relax. LOL. You're very witty and clever (and obviously very bright), and I always enjoy reading whatever you have to say. Keep those zingers coming.
Anonymous said…
Females and younger kids gathered insects and hunted small game, so they still racked up the fat and protein, Diana. Admittedly, paleo-town is very man-focused, but it's also the only place where women eating meat is considered completely healthy and normal and not gross or weird. The myth that women 'gathered' carbs only is a pretty problematic myth, as is the general cultural view in the West that meat is only for guys and women don't apparently need protein, just veggies and rice.
CarbSane said…
Hi Subcalva! Welcome & glad you got the commenting thing working. There are a few who still have problems and I don't know what the issue is ... I have no control over Blogger! :(

I agree with Kurt there. Nice quote!
Tonus said…
"rather than viewing this as evidence that glucose is not important, we should view this as evidence that glucose is so metabolically important that we have evolved way to make sure we always have it."

As opposed to, say... vitamin C?

I think that one of the benefits of having developed our minds past the point of simply existing and reacting on instinct is that we have much more control over our enjoyment of life. And that includes eating!

Yeah, there are foods and nutrients that we are better off avoiding or reducing, but the idea that we should limit ourselves to the essentials or try to eat like primitive man seems pretty extreme. Primitive man ate "paleo" by stabbing a wild boar to death and (after treating and dressing his wounds with mud and grass) cooking it as best he could over a fire or perhaps skipping the cooking part and just digging in!

Thanks, but I'll take a donut over that existence any day.
Diana said…

"The myth that women 'gathered' carbs only is a pretty problematic myth,"

Yah, and I didn't say that. I said that ONLY women gathered. Big difference. And they didn't gather carbs, they gathered plants.

I'm well aware of the fact that Aboriginal women and children gathered and ate insects and small game. But that's not really what we are talking about when we talk about hunting. Nope, we're talking about the heroic mastodon hunter, the bigger and tougher the game, the better.

I only said that gathering was associated solely with women, not that women (and children) never hunted. And I conjectured that the reason why the latter-day Paleo hacks and wusses go so crazy about the whole Paleo concept is because they have an inner psychological need to valorize anything that is specifically male.

"uys and women don't apparently need protein, just veggies and rice"

Oh stop exaggerating. Do you realize how inbred you sound?

Except for a small group of urban hipster pseudo-sophisticates, no one believes that or behaves that way. It's a class thang, methinks. I read on some vegan website that Sarah Palin had said, "There's a place for animals in my life. Right next to the mashed potatoes." Now please, I do not want to get in an argument about Sarah Palin! I only put it there to prove my point, that meat-eating and gender is a stupid fringe argument. The vast majority of women in our society eat meat.

Paleo, you truly have proved my point that the Paleo adherents don't think clearly, have an agenda, and that it has more to do with modern preoccupations than anything that really went on in the past.
Diana said…
As an aside, I just wanna say that it's perfectly understandable why hunter-gatherer people themselves would valorize hunting: it was damn dangerous, and provided delicious meat. I never said it was wrong for them, just silly for men who themselves couldn't take 3 steps outside without Goretex and insect repellent. Have a little respect for your foremothers guys.

Long time ago I saw on PBS a doco about the San!Bushmen, made by (I believe) Melvin Konner. I remember distinctly the part where Nisa, the main character, reminisced about her father's hunting prowess. "When my father looked at a giraffe, it was as good as dead," she said with tremendous pride.

But this is a woman talking about her late father! Of course, hauling home a giraffe was occasion for celebration. I don't have any problems whatever with going to the deep past to understand the roots of our current dilemmas, preferences, and good qualities. I do object to distorting them for an agenda.
Anonymous said…
diana, yes, women eat meat, but you are just firing a bunch of polemic. i'm american and in the american social milieu, women eating meat is something to be ashamed of. across classes most women don't run for the sashimi or steak or organ meats, all things paleo-ville is ok with. it's 'oh i don't eat red meat' or 'oh i only eat fish' or 'oh i only eat chicken (and only breast meat!) and fish, i'm trying to be healthy you know'.

that's my experience with actual non-famous women ranging from poor to upper middle class. it's all about the fruits and veggies, even if they're in juice form and packed with sugar. for two decades now i've heard women talk smack about how they don't like the texture of meat, how it's so 'heavy' and etc. this is something that is now part of the american dietary cultural fabric. chicken and fish are acceptable because they're 'light', but you're still only supposed to have those a couple times a week.
Tonus said…
I would probably associate the "oh, I don't eat red meat" line with a woman (usually a rather thin one who doesn't eat a lot of things) and I am familiar with the attitude that 'real men eat red meat' or words to that effect. But I don't agree that women in the USA are stigmatized for eating meat. At least not in the low/mid income social strata that I am familiar with.
CarbSane said…
I've got to come down with Diana and Tonus on this. While if I were to have to bet money on the gender of someone commenting that they don't eat red meat, my money would be "female", I'm not seeing any stigma in the US for women that do. Of all things I do/am that I've ever felt stigmatized for, eating red meat wouldn't even occur to me!
CarbSane said…
@Archie -- kinda busy at the moment but I've "bookmarked" your comment and will get back to you on that!
Diana said…
"Keep those zingers coming."
Happy to oblige!

Regarding meat and women, I would not put my money on "Oh I don't eat meat" being a woman or girl. I would put my money on "Oh I don't eat meat" being a certain kind of insufferable, upper middle class kid/person whose family history is several generations removed from manual labor. In other words, it's a class thang, not a sex thang.

Women make the overwhelming majority of food buying decisions in our society, at least amongst the married and cohabiting and households w/children, and the idea that they are buying meat for hubby/SO and kids, while cowering in a corner, shamed into not eating meat, is ludicrous.

Paleo hacks are such hacks.

My point stands: gathering in the Paleolithic era was women's work, and the modern obsession with "man the hunter" is wussbag wish fulfillment.