The Concept of Resistance Starch : discuss

stewgreenUK

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(This is an offshoot of my main post :
BBC "Trust Me I'm A Doctor" = "Don't I'm a TV Doctor"
as I first saw the concept in this TV show and as yet the topic appears to have no post of it's own on ISF)

- The Michael Mosley TV show had a number of dodgy science practices however The Concept of Resistant Starch does seem to be quite accepted, but I wondered if we could thrash out some of our skepticisms here.

The magic of Resistant Starch is that it is supposed to prevent diabetes, as easily digestible hot pasta, becomes hard to digest Resistant Starch so you don't get the same sugar rush into your blood and insulin need from your pancreas that is needed to get the surplus sugar out of your blood.

ie that warm cooked carbohydrates are very easy to digest and that leads to a sugar rush in the blood which leads to the pancreas being a bit hammered ..and could contribute to diabetes
- But when the very same meal is eaten cold or even reheated it behaves more like fibre ..ie more of it ends up down the toilet.
 
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http://en.wikipedia.org/wiki/Resistant_starch ..possibly dubious info

OK now I will offer a few ideas, I say debunk , but they are not cast in stone
- Debunk 1. Of course if you are doing some activity in the hours after eating you'll be using up the sugar anyway
- Debunk 2. The flipside of that : "much of it becomes to behave like dietary fibre" do you know what that means ? "half of the food you pay for is getting flushed down the toilet" . So I wonder if many people don't end up feeling hungry later and eat another portion of food ?
- Debunk 3. - I can accept that hot food might be easier to digest than cold and you may end up extracting more sugar from it. But when I soak pasta overnight and eat it cold it seems to me that since it is then like flour in water it is already half digested .. my body seems to process it fast. Indeed I switched to brown pasta , otherwise I got hungry too quickly.
Isn't the whole point humans cooking, that it is easier to digest & we get more calories from it ?

- Mechanism - how can reheated food be more difficult to digest than hot food ?..surely the less bonded a food the easier it is to digest ..That makes hot food easier to digest. And perhaps once cooled the same food is more bonded.

- hang on what examples of cooked then cooled carbohydrates do we have ? surely cakes & biscuits ..are they the new superfoods ?
 
Here is the article relating to the episode:
http://www.bbc.co.uk/news/magazine-29629761

Not being an expert, I was interested in the findings. We were told at a healthy eating group that spuds, and pasta can be bad for losing weight as they can fill you up for short periods, leading to eating more later in the day. The article suggests that by re-heating pasta, we can remove much of this effect. Would I be right in this?

I do like pasta salads, so I'm hopeful it is a healthy option.
 
stewgreenUK said:
- But when the very same meal is eaten cold or even reheated it behaves more like fibre ..ie more of it ends up down the toilet.
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So they're saying it really DOESN'T count if it's eaten straight out of the fridge just after midnight? How about over the sink?
 
If there is any difference, I can';t believe it is big enough to make a drop in the bucket of health.

For one thing, food stay in your stomach until it is body temp, then goes on to be digested. I guess the warming needed will delay the digestion?

Heating food makes changes, but they are mostly irreversible. You can't un-mash your beer ingredients by cooling them.
 
I see none of you deal with diabetics.
Food preparation is chemistry ....much of it rule of thumb.

That pasta coverts after cooking and then cooling to a slower glycemic response is no surprise at all.

How the food is technically and thermally processed
Hydration and heat raise food’s Glycemic Indexes. Carrots, for example, have a 20 GI when raw. The moment they are boiled, their GI rises to 50 as a result of the gelatinization of it starch content.

Certain industrial processes take gelatinization to the extreme. This is true for mashed potatoes and cornflakes as well as for binding agents such as modified starches and dextrinized starches.

These processes noticeably increase foodstuffs Glycemic Indexes (85 for cornflakes, 95 for mashed potatoes, 100 for modified starches.)
Likewise, exploding corn grains to make pop-corn or rice grains to make puffed rice increases the original food’s GY by 15 to 20%.

« Pastification », on the other hand, reduces Glycemic Indexes
Comparatively, there is a natural technical process which tends to block starch hydration: Pastification of coarse wheat. Extruding wheat paste through a drain heats the food in such a way that it produces a protective coating which slows down starch gelatinization.
While this applies to spaghetti and certain tagliatelles which are “pastified” (extruded under great pressure), it does not hold for raviolis nor lasagna and not even for fresh pasta which are hand cut and thus have a much higher Glycemic Index even if they are also made from durum wheat flour.

As we can see, we can use the same flour and end up producing foods with quite different Glycemic Indexes, at times they can be twice as high: raviolis 70, spaghettis 40.

Cooking at home also affects our food’s Glycemic Indexes.

Cooking al dente (5 to 6 minutes), for example, allows us to keep spaghettis GIs as low as possible while prolonged cooking (from 15 to 20 minutes) will raise GIs since it accelerates starch gelatinization.
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more
http://www.montignac.com/en/the-factors-that-modify-glycemic-indexes/

the take away

How retrogradation inverses gelatinization
Starch, after being gelatinized when getting cold is subjected to further modifications.

With coolness gelatinized starch gradually begins to reorganize its amylose and amylopectin macro-molecules. This is what is known as retrogradation, a return (which can be more or less significant) to its former molecular structure. Retrogradation becomes more intense as time passes and temperatures go down.

Preserving amylase foods for long periods at low temperatures (41° Fahrenheit) stimulates retrogradation. Something similar occurs with food drying processes. Dry bread, for example, loses its humidity and stimulates starch retrogradation, as in the case of toasted bread.

Although retrogradation does not wholly reverse food gelatinization, it does contribute to lowering foodstuffs’ Glycemic Indexes. Spaghetti (even white refined), for example, will have a 35 Glycemic Index if cooked al dente and eaten cold (in salads).
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Now our good Dr Montignac translated this reality into a profitable nutrition company......but the fundamentals are sound......

It is very hard to fool the body's insulin response......and this simple experiment shows the results of the change in the pasta.....and the body's response.....it is very clear.



http://www.bbc.co.uk/programmes/art...leftovers-be-healthier-than-the-original-meal

no magic bullet - just a nifty way to shift hi-glycemic foods like freshly cooked pasta to significantly lower version

good article and sound science...my son is type one - he and I deal with glycemic response every day.
 
After converting to mg/dl, does a rise of 18 points , or less than 1 mmol, for 15 minutes mean anydranthing?
 
@macdoc - Thanks
- I get you how in practice for a diabetic That it is not so much a issue of total sugar digested, but rather about avoiding sugar spurts
- And that cooling a plate of pasta allows a layer of "shiny" to form around the "globules" making up the pasta so making the digestion process slower.
(An issue is "the reheating increases the effect " claim (as shown in the graph above, which is taken from the progs website) cos that is a surprise claim made from the experiment in the prog, add that to the lack of science rigor generally shown in the prog, means that we should be a bit skeptical)

- OK so Diabetic carefully controlling his diet switches to a bowl cold pasta today, and he avoids the sugar spurt he got when he ate the hot pasta yesterday.
But what about the claim that resistant starch prevents diabetes in 'normal' people ?
- I'll use an extreme example
Today I sit down with 3 bowls of pasta eat them very fast, washed down with sugary drink, followed by 2 pieces of chocolate cake ..and say"no diabetes for me I've had my resistant starch superfood!"
..I'd guess that that the sugar spurts could be quite high

..However if after 10 minutes of eating I go for a 5 mile run, am I using that sugar up straight away as it comes into my blood stream ..Everything has to be taken in context.

- Interesting to see nothing on resistant starch on the UK Health Service website www.nhs.uk
- also that it doesn't mean canned processed foods are better, as although tinned spaghetti has been precooked in cooling it had not formed that layer of 'shiny' so will be quickly digested.
 
Something to look at for the glycemic-impact-ophobes: How does a piece of ripe juicy fruit effect that curve? Blame man-bred grains of you want, but there ain't nutthin more natural then fruit.
 
we going off topic a bit, but the fruit we eat today isn't so "natural"
It's been thru masses of iterations of selective breeding
so it is much bigger and sweeter than millions of years ago
e.g. oranges in the jungle are small and bitter

"ain't nutthin more natural then fruit." ...does "natural"=good ?
if "natural"=what we have evolved to eat, then that is cooked food, and processed food like beer etc. +(milk & beer for 20% of world)
 
- I get you how in practice for a diabetic That it is not so much a issue of total sugar digested, but rather about avoiding sugar spurts
- And that cooling a plate of pasta allows a layer of "shiny" to form around the "globules" making up the pasta so making the digestion process slower.
(An issue is "the reheating increases the effect " claim (as shown in the graph above, which is taken from the progs website) cos that is a surprise claim made from the experiment in the prog, add that to the lack of science rigor generally shown in the prog, means that we should be a bit skeptical)
Click to expand...

no reason to be skeptical of the concept - the blood doesn't lie and the food chemistry makes sense.

Prevent type 2 tho??.....bit of a stretch but I suppose it could be one factor of many - mostly exercise related.

Our modern foods are stuffed with sugars - king corn.... :(

Not surprising we have a type 2 plague.

Something like one in 8 New York City dwellers ( adults ) are Type 2 - many not being treated......can't recall where I came across that but that's an astonishing health care bomb in the making.
Part of that is ethnic populations that are more prone than some. ( some native American communities are 50% Type 2 )

It always blows me away when I swig a can of root beer I'm getting about 9 teaspoons of sugar....or is it tablespoons....the horror the horror.....deadly over time.
 
1 orange=23g, 1 large banana= 17g of sugar http://www.sugarstacks.com/fruits.htm
One teaspoon of sugar=4.2 g,
so thats about 9 teaspoons if you ate those 2 fruit together

If I ate them both on an empty stomach
am I really getting a much larger sugar rush that your root beer on an empty stomach ?

"blood doesn't lie" ..agreed proper repeated studies are fine, but the surveys done on this TV prog lack scientific rigour

- Of course I didn't watch that Alice Roberts "Horizon: Is Your Brain Male or Female?"
.. you can tell from the false-dichotomy title it's going to be dumbed down BBC pop-science ..the proper science in BBC progs is now outnumbered by the badscience
 
The proper science is on the Radio-4 dedicated science programmes. Often not the news programmes.
 
stewgreenUK said:
we going off topic a bit, but the fruit we eat today isn't so "natural"
It's been thru masses of iterations of selective breeding
so it is much bigger and sweeter than millions of years ago
e.g. oranges in the jungle are small and bitter

"ain't nutthin more natural then fruit." ...does "natural"=good ?
if "natural"=what we have evolved to eat, then that is cooked food, and processed food like beer etc. +(milk & beer for 20% of world)
Click to expand...

That's not true, I have done extensive research on this subject and there are wild fruits both sweeter and less sweet than our hybridized versions. This appears to be a popular but unfounded belief among certain circles.

I have to therefore ask you for evidence for your claim that fruit is much sweeter than it was millions of years ago.

Here is an article partially supporting my contentions:

http://rawfoodsos.com/2011/05/31/wild-and-ancient-fruit/

Contrary to popular belief, wild fruit—including the stuff we would’ve had access to during our evolution—is not necessarily any of the above. In fact, it can be bigger, tastier, and sweeter than anything you’ll ever find in the aisles of your grocery store.

Fruit is decidedly sparser once you get out of the tropics, but considering we were stationed in Africa until about 50,000 years ago, the flora of a backyard in Michigan might not be a great reflection of the plant life we encountered for the majority of our evolution. As a result, comparisons of cold-climate fruits to their wild ancestors (for instance, a Red Delicious versus a crab apple) tend to be misleading, and tropical fruits may offer more insight. Although we’ll probably never get a clear picture of the exact fruits available to early humans, we can look at the wild fruits growing today to get an idea of what nature is capable of producing on its own.

There’s a great book called “Lost Crops of Africa” (readable online) that has a brilliant section on wild fruit. The authors start by describing the vastness of Africa’s wild fruit supply:

Most of Africa’s edible native fruits are wild. One compilation lists over 1000 different species from 85 botanical families and even that assessment is probably incomplete. Among all those fruit-bearing plants, many of the individual specimens growing within Africa are sheltered and protected, some are even carefully tended, but few have been selected to bring out their best qualities, let alone deliberately cultivated or maintained through generations. They remain untamed. … Africa’s wild-fruit wealth is essentially unknown to science.
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I would have got that conclusion from
Ward Nicholson's writings http://www.beyondveg.com/
he was the first guy to write extensively debunking raw food diets .. after coming over from years of being a true-believer
wild fruit vs cultivated fruit
http://www.beyondveg.com/billings-t/fruit-table/wild-cultiv-fruit-1a.shtml
I didn't find anything conclusive on a quick search on Google scholar
checking words like prehistoric fruit, paleolithic sweetness vs modern

Neverless it doesn't make any difference to my point
He said "there ain't nutthin more natural then fruit."
and I was arguing that the fruit we eat today normally isn't a fair representation of what we evolved for 20,000+ years ago
I think my claim that still stands up
 
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stewgreenUK said:
(This is an offshoot of my main post :
BBC "Trust Me I'm A Doctor" = "Don't I'm a TV Doctor"
as I first saw the concept in this TV show and as yet the topic appears to have no post of it's own on ISF)

- The Michael Mosley TV show had a number of dodgy science practices however The Concept of Resistant Starch does seem to be quite accepted, but I wondered if we could thrash out some of our skepticisms here.

The magic of Resistant Starch is that it is supposed to prevent diabetes, as easily digestible hot pasta, becomes hard to digest Resistant Starch so you don't get the same sugar rush into your blood and insulin need from your pancreas that is needed to get the surplus sugar out of your blood.

ie that warm cooked carbohydrates are very easy to digest and that leads to a sugar rush in the blood which leads to the pancreas being a bit hammered ..and could contribute to diabetes
- But when the very same meal is eaten cold or even reheated it behaves more like fibre ..ie more of it ends up down the toilet.
Click to expand...

I didn't know anything about this, and now know a little bit.

Here is an article discussing resistance starch and its physical basis. It describes the macromolecular structure of starches including the four classes of resistance starch.

http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2006.tb00076.x/pdf

Here is another article where foods are eaten and blood glucose and insulin levels measured at time periods afterward. It has graphs which are very similar to the one posted above by macdoc, but has error bars and statistics, which always make me happy!
http://www.nature.com/ejcn/journal/v59/n11/pdf/1602238a.pdf

The authors studied potato meals after cooking, and after cold storage, and with vinegrette, in 13 volunteers. Yes, chilling potatoes does increase the amount of indigestible starch, and does slightly reduce the immediate (15-30 min) rise in blood glucose after eating. Statistically, the insulin levels and blood glucose measurements are different at 15 and 30 minutes but not for the rest of the 2 hour observation period. The statistical difference is not huge.
 
With regard to resistant starch preventing diabetes, here is a relatively recent evidence based dietary guideline for diabetes:

http://care.diabetesjournals.org/content/25/1/148.full

I note the following excerpts from this lengthy piece:

"Resistant starch.
Resistant starch (nondigestible oligosaccharides and the starch amylose) (Table 1) is not digested and therefore not absorbed as glucose in the small intestine. It is, however, almost completely fermented in the colon and produces about 2 kcal/g of energy (46)...All studies found some reduction in postprandial glucose and insulin responses to the first meal, but observed mixed results after the second meal. Long-term studies have not consistently confirmed these results (155,158,159,160,161)...There is limited evidence for the following statement:

Resistant starches have no established benefit for people with diabetes."

"Glycemic index.
There have been nine studies (80,82,107,108,109,110,111,112,113) involving type 2 diabetes subjects (n = 129) that have compared low−glycemic index and high−glycemic index diets for longer than 1 day. One study (107) reported lower HbA1c levels in low− compared to high−glycemic index diets, whereas four studies (80,82,108,109) reported no differences in HbA1c levels. Three studies (110,111,112) reported significantly lower fructosamine levels in low− compared to high−glycemic index diets, whereas three other studies (108,109,113) reported no significant differences in fructosamine. No differences in fasting plasma glucose concentrations were reported in eight studies (80,107,108,109,110,111,112,113), and no differences in insulin levels were found in two studies (107,109)."

"With regard to the glycemic effect of carbohydrates, the total amount of carbohydrate in meals or snacks is more important than the source or type.

There is some evidence for the following statements:

Although the use of low−glycemic index food may reduce postprandial hyperglycemia, there is not sufficient evidence of long-term benefit to recommend general use of low−glycemic index diets in type 2 diabetes patients."

I found this quite surprising:
"There is strong evidence for the following statements:

Sucrose does not increase glycemia to a greater extent than isocaloric amounts of starch.

Sucrose and sucrose-containing food do not need to be restricted by people with diabetes based on a concern about aggravating hyperglycemia. However, if sucrose is included in the food/meal plan, it should be substituted for other carbohydrate sources or, if added, be adequately covered with insulin or other glucose-lowering medication."

So, although resistance starch is real and measurable, and refrigerating your pasta or potatoes overnight before eating them does slightly reduce the blood glucose and insulin peak after 30 minutes of consumption, you will still end up with all the calories in the end (through fermentation), and this practice will not prevent you from getting diabetes.

You are better off losing weight, and getting plenty of aerobic exercise.
 
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