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Resistant starch (RS) is most notably found in tiger nuts, green plantains and certain foods that have been cooked and cooled, like legumes, grains and potatoes. The starches are called resistant because they resist being digested in the small intestine. They remain intact to become food for the good flora located in the colon.
Four kinds of resistant starch
There are four kinds of resistant starch. Each exists or is formed differently:
- RS1 is bound within the fibrous cell walls of certain foods: whole-grain foods, seeds, tiger nuts and legumes.
- R2 exists in certain raw foods and goes away when heated. You find this type of starch in green bananas, high-amylose corn, Basmati rice and raw potatoes.
- RS3 occurs when certain foods are cooked and then cooled; rice, beans and potatoes are examples.
- RS4 is not whole food sourced. It is a synthetic form that’s chemically modified to make it resistant to digestive enzymes.
The role of butyrate
When good bacteria in the colon consume resistant starch, they produce a short-chain fatty acid called butyrate. The cells of the colon are called T cells. T cells are fueled by butyrate. T cells provide a layer of defense against pathogens and help strengthen the immune system.
It makes sense that feeding T cells is beneficial, especially for those with autoimmune diseases. Repeatedly, an abundance of T cells in laboratory rats have been shown to reduce inflammation and even to prevent immune responses.
Excess butyrate moves into the bloodstream and benefits insulin levels and liver function.
FOODS THAT CONTAIN RESISTANT STARCH
For quick reference, see a list of 10 EASY to eat resistant starch foods at the bottom of this post.
Easy to eat resistant starch sources include:
- green bananas and green plantains — Very green plantains and bananas are easy for most of us to source, and they’re a whole food. Plantain flour can also be stirred into water or a smoothie. What do you do with fresh green plantains or bananas? You dehydrate them. Here’s a recipe for either crackers or
fruit leather from plantains. If you cook green plantains a lot of the resistant starch is lost. So these recipes keep the fruit raw, (which is not delicious on its own). Here’s a good recipe for Brownie Bite Cookies, full of RS2. - RS3 foods or retrograded foods — those that have had their starch cooked and then cooled, rendering it resistant: rice, beans, oats and potatoes. These foods may also be reheated once cooled.
Examples of prepared foods that contain resistant starch due to retrogradation are:
- potato salad
- sushi rice
- cold bean salad
- pasta salad
All of these foods could likely be dressed in part with apple cider vinegar. Vinegar is said to assist in the digestion of RS into butyrate.
MORE COOKED AND COOLED RS3 FOODS THAT CAN BE REHEATED
Cooked and cooled (RS3) foods can be reheated. Think:
- refried beans or chili made ahead of time, chilled and then reheated
- cooked al dente pasta put in the fridge and then reheated briefly in salted boiling water
- reheated mashed potatoes (or see these yummy Smashed Potatoes)
- and leftovers in general!
Yes, sometimes leftovers can be healthier than the original meal.
AVOID PROCESSED SOURCES
Surprisingly, most advocates for increasing RS in one’s daily diet originally recommended a factory-made food, Bob’s Red Mill Potato Starch, working up to two to four tablespoons a day. I don’t agree with this approach.
The goal for restored health involves getting away from factory-made foods and having a whole food diet. Potato starch may feed good bacteria; but there are plenty of whole foods that do that too. What potatoes does Bob use to make that starch? (Hint: they’re not organic and potatoes always make the Dirty Dozen list of most contaminated foods.)
OTHER GRAIN-FREE SOURCES OF RESISTANT STARCH
- Cassava flour (find it here). Cassava makes great baked goods, like these muffins or even in this hot chocolate.
- Tiger nuts and tiger nut flour are great. Here’s a Tigernut “Bran” Muffin.
- Jerusalem artichokes are another good source; fermenting them is ideal (like this).
START SLOWLY
All RS advocates warn that excess gas results from the initial introduction of this new food, and lasts for about two weeks. Most who’ve responded to blog forums on this topic say it subsides over time as the gut flora get used to their new food. I can now attest to this myself, having phased off of the GAPS diet and introduced multiple sources and quantities of RS. Start with 1 teaspoon to 1 tablespoon of resistant starch daily. See how your gut and bowels respond; and then proceed accordingly.
I appreciate the healthcare practitioners who counsel a slow introduction of RS-containing foods and are mindful of proper pre-digestion techniques.
PREDIGEST RS GRAINS/LEGUMES
Many RS proponents do not themselves know about phytic acid and enzyme inhibitors, so they are not teaching proper soaking and sprouting. These sites on resistant starches are blindly recommending whole grain bread and brown rice, with no knowledge of sprouting or soaking grains, making RS just one more nutrition fad — done without full understanding of foods and how they digest.
Leaky gut gets worse when it’s exposed to whole grains that haven’t been pre-digested. If you’re interested in incorporating grain or legume-sourced RS, make sure to soak your grains or legumes properly first.
HEALING DIETS AND RS
If your health is good or your leaky gut is mostly healed, if you do a Paleo diet or AIP (autoimmune protocol), resistant starches may be something you want to try.
Those on the GAPS diet should not eat these or any starches. They can be challenged if total healing is suspected. In the meantime, GAPS patients can enjoy prebiotic foods like leeks and onions, not cooked too long, to protect the prebiotic qualities. Fermented asparagus is another good GAPS Diet option.
10 EASY to eat resistant starch foods
- cooked and cooled rice (feel free to reheat it)
- cooked and cooled beans (this includes canned beans or reheated leftover chili)
- cooked and cooled potatoes (this includes Smashed Potatoes, leftover baked potatoes, potato salad or leftover mashed potatoes)
- any tiger nut flour recipe (see muffins, tortillas, pie crust and cookies)
- green banana flour (very easy to add to smoothies)
- cassava flour recipes (see waffles, biscuits and pancakes)
- pasta salad or leftover pasta (this includes Jovial’s new cassava pasta or rice pastas)
- green plantain treats (see Brownie Bites)
- leftover or cooled and reheated oatmeal
- hummus
SOURCES
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/resistant-starch
https://www.sciencedirect.com/science/article/pii/S1074761309003690
https://www.precisionnutrition.com/all-about-resistant-starch
https://pubmed.ncbi.nlm.nih.gov/15287678/
https://pubmed.ncbi.nlm.nih.gov/25582732/
Jessica says
This is a good post, I think a lot of people don’t realize the difference in starches.
Megan Stevens says
Thanks, Jessica! Yes, it’s great to understand their different roles in our body, both negative and positive! 🙂
reneekohley says
Very interesting information!
Eileen says
This is very helpful information. I am on full GAPS, but do not yet eat lentils, as they can really irritate my gut. I would love for you to add an image to the post, so I can pin! 🙂
Megan Stevens says
Yes! My site will be a .org in about a week and then all the photos will be pinnable, yea! Adding the photo today, you bet!
How We Flourish says
Very interesting! I don’t really know anything about different types of starches, so thanks for the informational post.
Susan Finney says
Thanks for this information, had never heard of RS before but we did make the waffles and have had NO gas. I think people probably have that happen when they eat the Bob’s potato starch. On to new knowledge and a new food, thanks to you!
MJ says
Hi, I want to introduce more RS in my diet. I have a couple of questions :
1. I eat a lot of lentils, beans, chickpeas…is it better if a make them 1 day ahead and refrigerate? And And then just warm them up a little.
2. Green plantains….i am from a part of Bolivia that eats lots of plantains. What about cooking green plantains like in the oven, cool and refrigerate them. Will it work as good as raw?
3. Tapioca starch….is know is not the optimal, but since it is available here. Cook with it ( bake or thickening agent) or raw in a smoothie?
Thanks!!!! ?
Megan Stevens says
Hi MJ,
Thanks for your questions!
1. Yes, making beans a day ahead is great. Some sources say that reheating a cooked and cooled bean actually increases the RS. As long as it’s been cooked and cooled once, it can be eaten cold or reheated.
2. Green plantains, on the other hand, are a different kind of RS (2) that must stay raw and never be cooked. Once cooked most of the RS is lost.
3. Cassava belongs to the RS3 category; so it’s a good one to eat cold after it’s been cooked, or reheated after it’s cooled. And cassava flour works great. But tapioca, derived from cassava, does not contain RS.
Blessings!!
MJ says
Thanks Megan!…what about tapioca starch? Is it OK to add it to smoothies? I read it has kind of a little bit less than potato starch but still a lot
Megan Stevens says
Sure, happy to help. 🙂 You can use cassava flour, if you’d like.
linda spiker says
Very informative! Pinning.
Megan Stevens says
Great! Thank you.
Eileen - Wellness and Workouts says
I’m happy you added an image to this. Such a great post! Will pin. 🙂
Megan Stevens says
Yay! Thanks, Eileen!
Emily @ Recipes to Nourish says
I totally agree with the potato starch … I see that recommend all the time and think how is that good? Non organic potatoes – no thanks. I have really been enjoying incorporating healthy RS like cassava flour. Thanks for sharing this Megan! Always appreciate your knowledge.
Megan Stevens says
You’re welcome, love! 🙂
Renee Kohley says
Thank you for this! I am working on getting more RS into our diet!
Megan Stevens says
Yay, wonderful.
Oh Snap! Let's Eat! says
This is super informative – I had no idea anything about RS… looks like I need to do more research! Thanks!
Megan Stevens says
You’re welcome. I’m so glad you know now!
Nicky says
Thank you for this information. I didn’t know that RS was beneficial and why I should incluce it in my diet.
Megan Stevens says
You’re welcome, Nicky. So glad it was helpful!
Elle @ Only Taste Matters says
Thanks for the great information! So helpful!
Megan Stevens says
You’re welcome. I’m so glad!
Allie says
Hi Megan! Great post, very helpful, as I am in the initial stages of reintroducing RS now after being on GAPS. A couple questions for you:
Properly preparing/soaking grains and legumes involves fermenting them, right? For those with SIBO, fermented foods are contraindicated, at least according to most (but not all) experts. So I’d love to start including beans in my diet for RS purposes (and since my doctor has prescribed me to start eating more foods that promote the production of butyrate), but in order to properly prepare them I would need to ferment them, thereby making them not okay for me since I am still healing my SIBO. Am I thinking rightly about this?
Thank you for your advice!
Allie
Megan Stevens says
Hi Allie, cassava doesn’t bother me; but tapioca does. But the nature of your sensitivity will certainly affect the answer. What reaction does tapioca cause in you?
2. Great question. The fermenting that occurs with the predigesting is occurring outside your body so that it won’t happen inside your body! 🙂 When foods are hard to digest they ferment in our guts. So by fermenting/preparing/soaking beans or grains, you are preventing or reducing the effect the food will have on your SIBO. When this is not true is with a living fermented food, and thus the confusion. Fermented foods like sauerkraut or yogurt are not cooked after fermentation or predigesting. The living probiotics exacerbate SIBO. Cooked foods that have been fermented are not fermented to create probiotics; they are fermented to break down anti-nutrients. So fermented foods like yogurt or kraut should not be eaten with SIBO. But fermented foods like beans and grains can be attempted. Even if they don’t digest well, it won’t be the SIBO being exacerbated by flora. This is the book by Norman Robillard Ph.D. that tells you which foods cause more or less fermentation in the gut, their fermentation potential: http://amzn.to/1U5ZM8j
Allie says
Hi Megan! My tapioca sensitivity came up in an IgG/IgA food sensitivity test I recently took; I don’t know what it actually does to my body since it’s been so long since I had it (likely in a processed gluten-free product that I ate prior to starting GAPS) and since I wasn’t in tune with my body enough at that point to realize it was bothering me. So with that in mind, do you think I should give cassava a try or not?
Re: fermenting/predigesting foods, thank you for that wonderful explanation! So helpful!! I know that each food’s RS amount can change depending on if it’s been cooked or not, cooled, ripened or not, etc. Do beans and lentils have a high amount of RS after they’ve been predigested/fermented and then cooked? In general does predigestion/fermentation change the RS content of foods at all? Do you know of a source you could point me to that would have all this type of info in one place? Thanks again!
Megan Stevens says
I do not have much confidence in the IgG/IgA food sensitivity test; so yes, I think it’s worth a try to give cassava a try. 🙂
You’re welcome. Beans need to be cooked and then completely cooled to gain their RS3. They can then be reheated. To learn more specifics, my post on the topic was just published over at TraditionalCookingSchool.com: http://traditionalcookingschool.com/2016/03/22/13-prebiotic-foods-to-improve-gut-health/ It should give you more guidelines about which foods are prebiotic and how RS foods should be eaten/prepared. 🙂
Allie says
You have me so curious now about the IgG/IgA testing. Why do you not trust it? Is there something I should know before I spend any more $ on it?
Megan Stevens says
It is not very reliable. It changes based on what you have or haven’t eaten, as well as other factors. The elimination process and the food intolerance evaluation have been much for helpful to us.
Allie says
Another question: Sprouting a food (like lentils or seeds, for example) and then eating it raw would not exacerbate SIBO because it’s not a living fermented food, right? (even though it wasn’t cooked after soaking/sprouting as you talked about above). I’m thinking of the recipe you linked to that are for sprouted raw lentil slaw, for example.
Megan Stevens says
Correct. 🙂
Mandy Fuller Fowler says
This is really interesting information. I’ve just started learning about RS and want to incorporate it in my families diet, but there’s a lot of contradictory information out there! I have a couple questions for you.
1. How do sweet potatoes compare with white potatoes as a source of RS, and do they need to be cooked and cooled also?
2. What about oatmeal? I’ve read raw oats are a good source, toasted oats are a good source, and also that you can cook oatmeal, refrigerate, and then eat it cooled. Which form would have the most RS and is it important to soak oats first as with other grains?
3. Do you think green plantains are a better choice than green bananas and why?
Thank you!
Mandy
Megan says
Hi Mandy! Oats are good source if used to make overnight oats OR cooked and then cooled (okay to reheat). I do like to soak my oats overnight before cooking. I just put a splash of ACV in the water, and then rinse before cooking as usual. Green plantains and green bananas are both good sources, as long as they’re not cooked. Sweet potatoes are not a good source. White potatoes do need to be cooked and cooled (again, okay to reheat).
Catharine Gunderson ("Cat") says
I would like to know if you can answer Mandy Fuller’s question above. I love this information. I have been resisting going on the GAPS diet for years. 10 or 11 years ago I had a test and found out I was at the extreme end of the leaky gut test, and my brain has been faltering more and more over the years. Now my sleep is really bad, 4-5 hours a night, and I feel so exhausted. But maybe this new awareness of resistant starch. Just started to learn how important Butyrate is, so this builds on that. Can’t wait to start substituting in my diet. This info should be out there more than it is.
Megan says
Hi Cat, in answer to Mandy’s questions, oats are good source if used to make overnight oats OR cooked and then cooled (okay to reheat). Green plantains and green bananas are both good sources, as long as they’re not cooked. Sweet potatoes are not a good source. Best wishes in your health journey!
Mindea Vinegar says
Apple cider vinegar also help
Esther Ruth Greenfield says
I have read that once potato flours heated it no longer is a resistant starch. In fact the label on BOb’s pot. starch apparently says it is heated. So….wondering if cassava or tigernut flours are still a resistant starch after being heated? Love the idea of just getting green bananas from the store and making my own dehyrated powder.
Megan says
Hi Esther, thanks for your questions. There are different categories of RS. Potatoes belong to two categories: RS2 when raw and RS3 that needs to be cooked then cooled for the RS to form. RS3 foods may also be reheated after cooling. Cassava is in the RS3 category: RS3 and must be cooked and cooled for the RS to form. Some flours are heated enough in their dehydrating process to qualify, such as Otto’s. Tiger nuts belong to the RS1 group with nuts and seeds because the starch is bound within the fibrous cell walls. Green bananas are RS2 and must be eaten raw. The RS is lost when heated. Yes, lovely to make your own green banana flour! 🙂 Just keep the heat low.
Deborah says
When using cassava flour for a resistant starch can you put it in a smoothie raw right out of the bag or does it need to be heated and then cooled like in your hot chocolate recipe? Thank you!
Megan says
Hi Deborah, it depends on the brand of cassava flour. But it is likely. Definitely yes, for Otto’s, as I’ve spoken to them myself. Companies use dryers to remove moisture from cassava flour, and the heat does get hot enough that RS3 is formed in the cooled flour, which is no longer raw.
Adriana says
“Many RS proponents do not themselves know about phytic acid and enzyme inhibitors”. I would very much have liked a section explaining this. I am somewhat mystified as the lack of explanation given that it sounds so very important.
Alex says
Do you still get the carbohydrates from those foods if the body doesn’t digest it by itself?
Megan says
Yes, you still get the carbs from those foods, good question.
Charity says
I notice that basmati rice loses its resistant starch when cooked? So is it a correct understanding that if I wanted to gain resistant starch from basmati rice I’d have to b easy it raw/uncooked? Is there a different variety of rice you would recommend?
Megan says
Hi Charity, do you have a source for that? I have never heard that about Basmati before … when it cools, RS should indeed form with Basmati or any rice.
Deborah Lee says
I am about to can a lot of potatoes. I will putting them in raw and they will cook in the canning process. Will the fact that they will be room temperature in storage be cool enough for RS to form or should I put them in the fridge for a certain amount of time to let it develop? If they need chilling can I do it prior to storing or should I chill it prior to eating?
Megan says
Hi Deborah, good questions. I’d refrigerate after canning. Once chilled for any length of time the RS is formed, then you can put back to room temp for long term storage. 🙂
Sarah Holland says
Hi Megan, a couple of questions if that’s OK?
1) Is brown rice better than white rice (such as basmati) for RS?
2) I’m also struggling to find potato starch labelled as raw. Is something labelled as organic potato starch as effective as raw?
Megan says
Hi Sarah, happy to help. Both brown rice and white rice have similar amounts of RS. They are different in other ways, but not their RS content. Don’t worry about raw with potato starch. You just need organic, like this one: https://amzn.to/42sWnpQ Cheers.
Tina says
Hello! I have enjoyed reading your article and post. Can you tell me about oat fiber ( not flour) and oat bran?
Megan says
Thanks, Tina. Sure: Oat bran is the casing that covers the oat groat and separates it from the husk, which isn’t edible. Oat fiber is the ground up hulls that are removed from the oat groats during the process.