Resistant Starch - A Solution In Search of a Problem page 3

[Neckhammer]

I'm gonna go out on what I consider a short limb and say that the rather large and versatile array of food that humans can survive and even thrive on is in no small part due to our evolving symbiotic relationships with these little buggers. I don't however see the population of your colon by starch eating buggers to be an absolute necessity. I would look at it as a variant for accessing fat (and vitamins) when its not abundant from animal sources. For instance many an HG tribe has been sorta quoted as saying "when the hunt fails we eat plants". Well if your living in an area or time of plenty then you will be getting all the fat you need from your kill. In times or areas that don't accommodate such you rely on these little buggers as your back up plan. I mean it takes relatively little time of reintroducing starch in your diet to be fully "re-adapted" to them. Levels of those microbes go down without a food source and come back up when foods a plenty, thats all. But that doesn't necessarily take into account what all otzi posts on some of these colon cells so I guess I'll keep reading .

[Neckhammer]

Oooh! To compliment the last video I posted... This is good stuff.

"The rainforest in your gut: A brief tour through your intestinal biome, why it’s messed up, and how to fix it" by Dr. BG & TG on Vimeo

Ahh, Dr. BG....I do like her blog. Have to watch sometime soon.

[Paleobird]

Most probably won't read this, but whatever. About butyrate.

The Carb-Sane Asylum: AHS(?) Bumpity Bump Bump: When is Fat a Fat?
The Carb-Sane Asylum: Resistant Starch & Butyrate: Eades' Shmashthematics

Important quote: "I think comparing these two sources of butyrate also deserves some scrutiny. Butyrate is a small water soluble compound. Delivered orally in butter, one wonders how much actually reaches the colon (large intestine) vs. the butyrate generated by bacterial fermentation of fibers "on location". Think what you will of the pharmaceutical industry, you can learn a lot from delivery methods employed. Indeed sodium butyrate is used in the treatment of Crohn's disease, and supplements are coated to ensure release in the ileo-caecal region and colon. This would lead me to believe that the majority of butyrate in butter is absorbed well before it gets to the end of the small intestine and large intestine in the fully developed digestive system."

"One wonders...." is not the same thing as the butyrate doesn't get there.

The rambling blog postings you linked included this "Cells lining the colon use butyrate as a major substrate for energy production in metabolic pathways that are not fully understood". That does not say that the butyrate couldn't have gotten there though the blood stream either, only that those cells use butyrate.

Umm. Still waiting for a reason not to just eat the butter and hold the potato.

I don't mean to change the subject too much here, but this thread has me wondering if there is any link between resistant starches and depression. I developed severe depression after 2.5 successful years of following an auto-immune paleo diet (no nightshades, potatoes, nuts, dairy, etc). I tried every dietary and supplement treatment I could come up with.

Looking at this, I would think my diet was pretty low in RS. Could that have contibuted?

Were you eating sufficient fats? Those can definitely have an effect on mental clarity and health.

Good point PB, why do we need butyrate from RS when we can get it direct from butter?
Also PB, do you think the large intestine should be relatively sterile then, ala Peat?

Not necessarily sterile but I think that the huge colonies of gut flora are things that get established and then want to be fed (their preferred food is any kind of fiber including RS). Peter at Hyperlypid did a very interesting three part series called "Whose Fat Is It Anyway?", showing how our "friendly" bacteria give us cravings so we will feed them. We need those bacteria as long as we are going to keep eating lots of fiber and starch. But do we really need the fiber and starch in the first place?

[pklopp]

That's quite a dissertation there, but I'm not sure what you are getting at.

Forgive me if I misrepresent the argument, but whenever I see the position in favor of eating resistant starch presented it essentially boils down to : "Resistant starch because butyrate." My dissertation, as you like to think of it, was an attempt to address what I understand as some of the inherent complexities of the topic

Many of the items you refer to are not resistant starches (RS), such as milk and bean sugars. These are sugars that are supposed to be digested in the small intestine, but when someone lacks the capacity to digest them there, they end up in the colon where they are fermented into unwanted and sometimes harmful chemicals.

Resistant starches are part of a family of carbohydrates that humans cannot digest as are the oligosaccharides raffinose and stachyose in beans. Your claim that these are "supposed to be digested in the small intestine" is simply wrong, which should make people regard any other claims you make relating to the biochemistry of the process with a very skeptical eye. When you speak of oligosaccharides being fermented into "unwanted and sometimes harmful chemicals" it would be really nice if you could come up with your own dissertation explaining exactly how this works and how it differs from RS fermentation.

Fermentation is a very primitive form of energy metabolism which uses simple sugars as inputs and generates a number of outputs. Pay attention to the bit that I've emphasized in the previous sentence ... simple sugars, that is to say, monosaccharides.

When it comes to the fermentation of _any_ carbohydrate, whether that is resistant starch, raffinose, stachyose, inulin, or other fructans, the first step is _always_ the enzymatic hydrolysis of the oligo / poly saccharide into simple monosaccharides. Then, those monosaccharides are fermented into various byproducts.

So, raffinose, which is a trisaccharide comprised of glucose, fructose, and galactose, is first broken down into these simple sugars in the large intestine by bacteria that have the necessary enzymes to do so. Once this happens, the simple sugars are fermented. Your body is perfectly capable of absorbing glucose, fructose, and galactose. It is incapable of breaking down the trisaccharide, however, which is why it appears intact in the colon to ferment.

What does this have to do with resistant starch? Quite a lot, actually, since bacteria in the colon never ferment polysaccharides, but rather monosaccharides, this means that a resistant starch looks just like glucose to bacteria in your colon. Various bacterial species that possess the necessary enzymes to hydrolyze oligosaccharides into mono and disaccharides also secrete these hydrolases into the extracellular matrix. The net result of all of this is that you get a soup of monosaccharides in your colon, irrespective of the ultimate source of the polysaccharide

So when it comes to raffinose, just like resistant starch, it looks like glucose to the bacteria in your colon, but it comes with some fructose and galactose for good measure. Nevertheless, the exact same bacteria that can ferment the glucose from RS can ferment the glucose from raffinose, there is no functional difference there.

RS is actually a family of 4 types of RS...

RS1 Physically inaccessible or digestible resistant starch, such as that found in seeds or legumes and unprocessed whole grains

RS2 Resistant starch that occurs in its natural granular form, such as uncooked potato, green banana flour and high amylose corn

RS3 Resistant starch that is formed when starch-containing foods are cooked and cooled such as in legumes, bread, cornflakes and cooked-and-chilled potatoes, pasta salad or sushi rice. The process of cooking out the starch and cooling it is called retrogradation.

RS4 Starches that have been chemically modified to resist digestion. This type of resistant starches can have a wide variety of structures and are not found in nature.

You are very fond of this Wikipedia factoid, but I fail to see how it adds anything to our understanding here. Let me see if I can help in that regard ... pay close attention to the category designated as RS1 above. That, my friend, is insoluble fiber, and "physically inaccessible" means you cannot digest it ... period, whether you are a bacterium or a higher order multicellular organism, it's just not going to happen. RS2 and RS3, on the other hand, comprise what is known as soluble fiber, the stuff that can be digested by intestinal microflora and fauna ( the bacteria camping in your colon ) This brings us nicely to :

The typical SAD provides about 2-3g per day of RS, the typical LC Paleo provides about zero. I have seen studies that ancestral diets provided about 50g/day, mostly RS-1 and 2 from raw tubers and seeds. Most health boards think the optimal amount is 20-30g/day, but almost no one gets that without trying really hard.

Given that RS1 is functionally inert ( the equivalent of eating sand from a fermentation perspective ) it is imperative that we get some hard data regarding what the proportion of RS2 to RS1 is in that 50g/day number that you pulled out of thin air. Did that data come from peer reviewed health boards?

I have no idea what this means...a typical raw potato, about 1/2 pound, contains about 30g of RS2.

Right back at you ...

According to the USDA, your raw potato ( flesh and skin ) comprises 5g of fiber in the assumed 1/2 lb. serving.

So, if we are generous and assume that _all_ of the fiber in that potato were to be RS2 ( which it is not ), your numbers are still off by a factor of 6.

Cooked, it contains about 3g RS2. Cooked and cooled 9g RS3. A small green banana contains about 5g RS2.

I have no idea where you pulled these numbers from.

So, eating 1 potato a day puts you back to SAD levels of RS, eating 1 regular potato, 1 potato cooked and cooled, and a couple slices of raw potato puts you almost at the recommended range.

As recommended by the afore mentioned "health boards?"

A couple of studies for you to check out, not that they are a smoking gun for RS, but just to show the extent of research into RS:

http://ajcn.nutrition.org/content/67/2/322.full.pdf

Which says in part:

There were no significant differences in fecal dry weight, pH, or short-chain fatty acid concentrations, nor in the pH, bile acid concentrations, cytotoxicity, or osmolality of fecal water. It is concluded that in healthy men, supplementing the habitual diet for 1 wk with 32 g RS2 or RS3/d compared with glucose had no effect on putative risk factors for colon cancer, except for increasing stool weight and colonic fermentative activity

Seriously? You are using this study ( the highlighting is mine ) to support supplementing one's diet with resistant starch?

http://scholar.lib.vt.edu/theses/ava...d/ALDfinal.pdf
(Password protected thesis, can't cut-n-paste)

Umm... that study literally says that people who exercise get more RS in their diet :

The objectives of this study were to determine the consumption of resistant starch (RS) by regular exercisers (Blacksburg and San Jose (SJ)); and to analyze the eating and exercise habits of the subjects ... Prominent RS food sources in both groups were pasta, potatoes, bananas, and corn ... It appears that consumption of RS is higher among SJ subjects.

Maybe you're just warming up and saving your best for last?

Effects of resistant starch on the colon in healthy volunteers: possible implications for cancer prevention.

Nope, guess not, glad I didn't hold my breath because that last study found absolutely nothing:

During two 4-wk periods. 12 healthy volunteers consumed a controlled basal diet enriched with either amylomaize starch (55.2 +/- 3.5 g RS/d; high-RS diet) or available cornstarch (7.7 +/- 0.3 g RS/d; low-RS diet) ... Fecal concentrations and daily excretion of short-chain fatty acids were not different in the two study periods.

I have plenty more, but don't want to turn this into a 'I have more studies than you' situation.

Quality always trumps quantity, and your studies so far have been sorely lacking in the quality department.

The bottom line is, we know that a healthy gut microflora is very important to overall health, special cells in the colon feed on butyrate produced from RS in the colon, and RS is a special starch and not just anything that happens to end up in the colon [insert funny joke here].

No, there is nothing special about resistant starch, that was exactly the point of my dissertation. It is just a carbohydrate that happens to wind up in the colon, the exact and precise equivalent of a glucose enema.

-PK

[cori93437]

Oooh! To compliment the last video I posted... This is good stuff.

"The rainforest in your gut: A brief tour through your intestinal biome, why it’s messed up, and how to fix it" by Dr. BG & TG on Vimeo

Yep.
A healthy and fully functional gut is a good thing...

Between Primal, that, and THIS...
"Primal mind: nutrition & mental health—improving the way you feel & function & cultivating an ageless mind" by Nora Gedgaudas on Vimeo

I found what it took to really work for me and my specific issues.
I know that some people aren't fond of my way, but I've lived in this body, I'll take my own experience over someone who has never lived in my shoes.

Because I have to restrict sodium and can't eat traditionally fermented veg I continue to take a probiotic in addition to eating HF cultured dairy some days.

Nora G explains how much the gut affects a persons mental state as well.
It's really amazing how much getting the gut healed can change how easy the rest of it is for you IMO.

None of that means you need to eat potatoes though.

[Drumroll]

Yep.
A healthy and fully functional gut is a good thing...

Between Primal, that, and THIS...
"Primal mind: nutrition & mental health—improving the way you feel & function & cultivating an ageless mind" by Nora Gedgaudas on Vimeo

I found what it took to really work for me and my specific issues.
I know that some people aren't fond of my way, but I've lived in this body, I'll take my own experience over someone who has never lived in my shoes.

Because I have to restrict sodium and can't eat traditionally fermented veg I continue to take a probiotic in addition to eating HF cultured dairy some days.

Nora G explains how much the gut affects a persons mental state as well.
It's really amazing how much getting the gut healed can change how easy the rest of it is for you IMO.

None of that means you need to eat potatoes though.

I am slowly watching every AHS video they've posted so far. I just finished Nora's vide you linked to, it was great.

I'd add this to your list: "Wild animals, zoos, and you: The influence of habitat on health" by John Durant on Vimeo

This one is awesome. It explains the effect of environment on health.

[Samuel Jays]

Wow. Otzi was just schooled in Biochem.
Thanks for the posts, Pklopp.

[Chupo]

According to the USDA, your raw potato ( flesh and skin ) comprises 5g of fiber in the assumed 1/2 lb. serving.

So, if we are generous and assume that _all_ of the fiber in that potato were to be RS2 ( which it is not ), your numbers are still off by a factor of 6.

RS isn't counted as fiber. It would be in the 35.51 grams of starch, nearly all of which should be RS2.

[ChocoTaco369]

Just a small note: I've eaten cold potatoes on purpose with each of my past 3 meals. So far, no noticeable increases in gas. I get far worse farts from eggs. Hell, eggs produce some of the meanest gas of all. No carbs to ferment there. Protein farts are notorious for being the worst.

Here's a wild idea everyone: instead of snowballing theory, why not actually try it? Potatoes are pretty cheap and easy to cook. Spend $2 on a 5 lb bag, cook them in a big pan, toss them in the fridge and eat some with each meal until they're gone. See how you feel. If you're farting up a storm, maybe it's not worth it to you. If you don't have an issue with this, maybe it is for you.

[pklopp]

RS isn't counted as fiber. It would be in the 35.51 grams of starch, nearly all of which should be RS2.

This is to some extent irrelevant, and I don't particularly care to engage in a data source duel, because what I really want to discuss is whether one ought to go out of one's way to purposefully add resistant starch to one's diet. Having said that, however, I seem unable to help myself, so I will take exception to your assertion regarding the starch in a potato:



Take a look at the red arrow, which tells us that 2% of the starch in a boiled potato is resistant. So, of that 35 grams of starch, you're looking at a thoroughly underwhelming 0.7g of resistant starch. I find that the proportion of resistant starch attributed to potatoes tends to directly and positively correlated to how hard one is trying to convince you to eat an all potato diet.

From the table you can see that if you are really looking to get resistant starch from potatoes, you can double your yield by going to pommes frites ( green arrow ). Of course, you also do wonders for palatability with respect to boiled potatoes, a win-win.

Of course, the undisputed champions of resistant starches are beans and legumes ( rectangle ), so if flatulence is your cup of tea, you know what to do.

At this point, you may take methodological exception with the study that produced that table, or you may not particularly trust the Department of Applied Nutrition and Food Chemistry, Center for Chemistry and Chemical Engineering at Lund University, or maybe you believe that potatoes in Sweden are fundamentally different from those in North America? It really doesn't matter, because we can empirically prove that potatoes are pretty low in resistant starch, for the simple and undeniable fact that they do not produce flatulence, gas, and bloating nearly to the extent that beans do ... which is indicative of significantly lower rates of fermentation.

-PK