# Resistant starch and the glycemic index



## tummyrumbles

The first site explains the connection between resistant starch and glycemic index.

The second link leads to a very comprehensive list of resistant starch foods.

Basic summary:

While resistant starch is healthy overall, it can lead to IBS symptoms for a lot of us.

Resistant Starch is a type of fibre that is indigestible in the small intestine. It travels to the colon where it feeds colonic bacteria, which in turn causes gas. Starches need to be broken down to glucose to be digested. The glycemic index measures this glucose absorption rate.

Starch is composed of amylose and amylopectin. Amylose resists digestion and the higher the amylose content a food has the less it is absorbed in the small intestine. Starches primarily composed of amylopectin on the other hand will be more easily digested and become glucose much quicker. These foods have a higher glycemic index.

It's important to know that high glycemic index foods increase blood sugar and are generally considered unhealthy.

Cooking methods can alter GI levels.

http://www.montignac.com/en/the-factors-that-modify-glycemic-indexes/

http://freetheanimal.com/wp-content/uploads/2013/08/Resistant-Starch-in-Foods.pdf


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## Nojokeibs

Isn't SCD the exact opposite of this? Has anyone else noticed that this theory and the SCD one are diametrically opposed? Is it because SCD is for IBD and we are IBS?


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## tummyrumbles

The specific carbohydrate diet mainly excludes all grains and vegetables starches like potato, sweet potato etc, but it includes high FODMAPs, some legumes and nuts. Allowable foods are meat, all non-starch vegetables and all fruits and nuts, and some non-lactose dairy. The science seems a bit wonky because it's based on a low inflammatory diet that is easy on the digestion but then includes FODMAPs and legumes. I'm surprised legumes are advised for anyone with any sort of bowel disorder and these aren't simple sugars anyway.

The paleo diet also excludes grains but allows complex sugar veges (FODMAPs) and safe, vegetable starches. The paleo view on safe starches is that they lack the toxins of grains. This is all very general because a lot of diet experts have their own slant on whether certain foods should be allowable or not, like nuts. Basically paleo excludes agricultural foods we're not adapted to eat like grains, legumes, dairy.

A low residue (low fibre) diet is often recommended for Crohns and IBD. It excludes high fibre foods like whole grains breads, nuts, cereals, seeds and fruits and generally limits fibre to less than 10 grams a day. The low residue and FODMAP diets are only designed to be short term diets as they're not considered healthy.

This is why I don't follow any one particular diet. IBS means we have an irritable bowel and a lot of things cause this irritability, not just starches - but alcohols, too much fibre, too much fats, FODMAPs. It's good to investigate these diets to see the underlying theory but then you have to individualise them to suit you. Starch is a troublesome food for a lot of healthy people as well, not just those with IBS so generally any diet that excludes starch, especially grain starch, will reduce gas. But starches fill us up and you're more likely to give up if a diet is too strict. I think IBS needs a pragmatic "one-size-fits-all" diet that accepts that some of us prefer to eat certain "bad" foods like grains but advises the best method of cooking preparation to reduce symptoms.


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## Moises

One of the links is about factors that modify the glycemic index.

Norm Robillard, who wrote a book on IBS and does not recommend RS (resistant starch) for IBS bases his regimen on the gylycemic index (GI).

The theory is as follows:

1. IBS is caused by SIBO.

2. SIBO is caused by residue in the gut.

3. Residue in the gut is caused by eating foods that are not fully absorbed.

4. Meats, fats, and eggs are (virtually) fully absorbed (if not, take enzymes).

5. The degree to which starches are absorbed is measured by the GI.

6. Starches with a high GI are better absorbed than starches with a low GI.

7. Starches with a low GI leave lots of residue in the gut.

8. IBS is caused by eating starches with a low GI.

http://digestivehealthinstitute.org/2014/03/24/resistant-starch/


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## Nojokeibs

The core of SCD is to make it easier to digest starch with a compromised gut lining. Starchy vegetables are allowed as is rice (but rice is only allowed later). Only those starches with high amylose are allowed, an example would be carrot. Her objection seems to be that amylopectin is too highly branched to be completely broken down and what's left is being fermented. Also she alludes to, but does not specifically say in her book that isomaltose may be more difficult to break down by microvilli than maltose, and only amylopectin produces isomaltose. This is from Chapter 5 of "Breaking the vicious cycle" by Elaine Gottschall BA, MSc.

She does indeed recommend onions with foods and other high FODMAP foods. She wrote her book in 1986, long before FODMAP was a glimmer in any scientist's eye. That's why I mix her diet with the FODMAP diet and find that it works fine. One criticism I have of her diet is that she doesn't take phytates into consideration either. With a gut lining problem, to use so much almond flour that hasn't been soaked and rinsed of at least some phytates, and then to avoid the use of yeast or any kind of sourdough starter that would reduce phytates, well, it seems like an oversight. Phytates will rob the person of minerals. But she does say the diet is only meant to be temporary, so I'm not sure how important that is.

I can't say I'm on board with all this "resistant starch" theory, either. It sounds like a throwback to the "FOS is good for you" days in the 1990s. But at least it brings up a good discussion. Potatoes are under study to see if all the amylose can be removed, and the gene for producing amylose can be turned off. So maybe this is a way to say "no thanks, I want my potatoes with amylose in them." On the subject of franken-izing food, I'm on the side of leaving it alone as nature made it. In fact, if I wasn't so lazy, I'd grow heirloom veggies.


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## tummyrumbles

We know that high GI foods are more easily digested but what effect does this have on overall transit time. Do SCFAs increase or decrease motility? And is a high GI diet how we got IBS in the first place? This is a hard thing to work out because there's so much conflicting information. Fibre on the one hand is supposed to speed things up but then methane, and probably the other gasses too, causes constipation in IBS. The rules for healthy people are reversed for IBS.

Are you better off eating mashed potato, with a high GI, low fibre, and low RS or Brussels sprouts with a low GI, high fibre and high RS. Most people with IBS would opt for the mashed potato but over a long period of time a diet like this would lead to constipation. If you cooked Brussels sprouts for 6 hours would they still be high FODMAPs or do they degrade to simpler sugars? And if they do degrade, then what's the point of eating them? These are questions I want to email the Monash Uni once I get it clear first. I can't find anything about this online.

Eating early is important as well. The earlier you eat the more likely evacuation will be a lot quicker and easier. Maybe IBSers and in particular Leaky Gassers need to eat as early as possible, at least before 9 pm and try to get to bed not later than 11 before the hunger pangs start. Eating early might be even more important than diet in a lot of ways because time can be forgiving. A 12 hour digestion is going to help evacuation a lot more than a 6 hour digestion and the SCFAs won't matter if all the residue is waiting to be voided anyway.

A site I looked at recently had a doctor saying that most people have gas just after eating but not during the night. Most of us are probably the opposite of this. If you're malabsorbing your food you won't get digestion gas straight away but when the food hits your colon - and that depends on your transit time.


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