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*Disclaimer: I am not a nutritionist or medical professional and make no claims to the contrary. Each individual’s dietary needs and restrictions are unique to the individual. You are ultimately responsible for all decisions pertaining to your health.
Isn’t starch bad??
Haven’t heard of the newest findings on resistant starch? Hold on tight my friend. You are in for a delightful surprise and a little more wiggle room in your “carb” options! Honestly, this is the reason to view starchy carbs with a whole lot more respect if you ask me.
Articles about resistant starch have been around for a long time now. If resistant starch is nothing new to you, this article will clear up some common misconceptions that are all over the blogosphere. Occasionally I will be lazy and just refer to resistant starch as RS.
Keto or other low-carb dieters listen up, as this information may be particularly vital to protecting you from destroying your gut biome and making you carb sensitive. This is truly one of the biggest missing pieces of the nutritional puzzle that I have ever seen.
Great news! The body does not use all starches the way we’ve been told (until relatively recently). In fact, it turns out some behave more like fiber and do not raise blood sugar.
These special starches now appear to be the key to everything that avoiding starch was supposed to do: gut health, body fat, diabetes…
Resistant starch appears to increase insulin sensitivity (that’s a good thing) which could have great potential for diabetes and metabolic syndrome! These special “newly” realized starches feed the good bacteria in the gut, and have a huge and growing list of proven and anecdotal benefits that beg for more research.
Benefits GALORE
Our bodies don’t digest resistant starch. The good bacteria in the large intestine do to some degree (if it hasn’t been destroyed). As beneficial bacteria consume the RS, they increase in number and produce fatty acids such as butyrate. Butyrate is a “superfood” for the colon that reduces inflammation and appears to prevent cancer. Let’s talk about the list of possible benefits of RS:
- Helping blood sugar issues: diabetes, impaired glucose and insulin responses, metabolic syndrome
- Improving bowel health: colorectal cancer, ulcerative colitis, inflammatory bowel disease, diverticulitis, constipation
- Counteracting harmful effects of red meat
- Reducing breast cancer risk
- Improving heart health: Cardiovascular disease, lipid metabolism, metabolic syndrome
- Increasing satiety: helps you feel satisfied and not overeat.
- Improving mineral absorption
- Treating cholera wow!!! Attracts all sorts of harmful microbes and cleans them out
- Feeding the good bacteria in the gut if it’s there. Makes probiotics work better.
- Oxidizes fat, reduces fat being stored=fat loss! In this study, researchers took biopsies from people’s buns. owie.
- Increasing telomere length= increased longevity {This is a huge deal. I’ll explain below}.
- Improving sleep
- Improved thyroid function and hormone balance
- Lowering total cholesterol, LDL cholesterol, and triglycerides
…and the list is still growing.
“Bio-hacking” telomeres
OK, before I continue, I really need to pay homage to Tim Steele (also known as Tater Tot) Author of “The Potato Hack: Weight Loss Simplified”. He pretty much re-lit the torch on all this RS talk after hitting a plateau and discovering an 1849 article on fat loss. It was about losing excess fat by eating potatoes and nothing else for a few days. This led him to more research and discovery- and results! He got so serious about it that he returned to school to get a Master’s degree in biotechnology to better understand what was happening! He is now one of the most reliable leading experts on resistant starch.
Science is now validating his enthusiasm for the humble misunderstood tuber and its starchy friends. You can learn more about Tim and buy his book here. I’ll likely be doing a review on it in the coming year after experimenting with his concepts.
Astonishingly, science is now pointing to resistant starch as having the potential to increase the length of telomeres. What are telomeres, you might ask? Here’s what Tim says:
Telomeres are “caps” found on the end of chromosomes. The length of telomeres is associated with your biological age (as opposed to how many birthdays you’ve had). A person with longer telomeres presumably is healthier than a person with shorter telomeres. Testing telomere length has become all the rage in certain circles of “bio-hackers” and all sorts of supplements are being sold to lengthen telomeres and improve health…one thing I’ve never seen recommended is fiber.
You can read Tim’s intriguing post in full here.
There are 4 main types of resistant starch. It’s especially important to understand the difference between RS2 and RS3.
- RS1: Found in things like whole or partially milled grains, nuts, seeds, legumes. This starch stays resistant as long as it is contained in cell walls, so it is reduced by milling and chewing.
- RS2: Found in certain raw starchy foods like raw green bananas, raw green plantains, raw potatoes, gingko starch. THIS TYPE OF RESISTANT STARCH IS LOST BY COOKING over 130º-140º AND DOES NOT COME BACK WHEN COOLED. Some of the starch may convert to RS3 after being cooked and cooled, but it will be much less. RS2 sources contain much higher levels of resistant starch than RS3 sources which have more digestible (therefore blood-sugar raising) starch. RS2 a popular choice for people on keto/low-carb type diets. But keep in mind they do different things so I try to get a little of both.
- RS3: Found in certain starchy foods such as potatoes, grains, and beans that have been COOKED and COOLED-TO-FRIDGE-TEMPS. This process is called retrogradation. Good news if you’re not fond of cold potatoes and such. Once they’ve been cooked and cooled, they can be reheated and eaten warm and have an even higher RS content!
Note: I don’t like to point the finger at anyone. But I had to address a friend’s legitimate concern after she read this article by a guest writer for Chris Kresser who says not to heat RS3 starches above 130º just before eating. I contacted Tim Steele to double-check my facts, and this was his response:
Chris Kresser is wrong about the 130 degrees. Everything I’ve read indicates that RS3 will remain intact unless subjected to high heat, above 400F or so, or high pressure. Normal cooking methods will not destroy it. 130 deg F is the point where RS2 turns to RS3, so perhaps that what Kresser was referring to.
Oh, happy day! So we can make fries out of that boiled potato that’s sitting in the fridge and still get a great benefit. Nice.
- RS4: Chemically modified starches are not found in nature. My family won’t be intentionally eating these.
Which type is best?
I get it. I often feel like I can’t bear to do… one. more. thing. I’m tempted to just grab a bag of raw potato starch (RS2 type) and take it as a daily supplement. Nice and easy and no prep work. Just spoon some in a glass of water and voila! Major life-changing benefits just like that. Well, in most cases that may be a great start, and a failsafe way to avoid miscalculating carbs if you’re counting them carefully.
But ya know, there is also a persistently idealistic side to me that believes so strongly in food in its whole form that I couldn’t shake my urge to research this further. I found this article:
Cooked/Crystallized RS3 Trumps Raw RS2: They are Vastly Different for Our Guts
Ok fine, my idealistic side wins this one. Time to grab those bootstraps and start prepping those taters and hunting the produce isles for green nanas. Ignoring the need for getting a variety of RS types may produce less-than-ideal results. So to answer “Which type is best?”: It doesn’t appear that one is better than the other, they’re just different.
When I get overly busy or can’t seem to find any truly green bananas, I’ll probably rely on raw potato starch from time to time for the RS2 portion of my resistant starch goals. We’ve gotta give ourselves some wiggle room for life, right?! Besides, there are many other foods that make it to my family’s dinner table that I’m sure will fill in the gaps. Hummus…black beans…corn tortillas…
What does this mean for keto or other low-carb diets?
serve and protect to be served and protected
By now I think we all understand that we aren’t just feeding the cells that make up our body. They only account for 10% of our total cells when including our microbiome into the equation. The other 90% (microbiome) need food too. If we’re tending to the flora whose job it is to symbiotically protect, nourish and heal us, there are some great rewards in store. If not, well, we’re starving our own dutiful soldiers. All that good stuff, such as serotonin, vitamins, and fatty acids that protect from cancer won’t get made. And who’s mopping up the toxins now?
my low-carb blunder
In my own personal opinion, Keto or LC done wrong, like just eating a bunch of meat and fat, may produce superficial gut relief by starving out “candida, etc.”… or so we’ve been told. Well, unfortunately, this actually can make it go more systemic and “armored”, opportunistically waiting for the tiniest bit of sugar to feast and explode its population. “Candida” can live off other things while waiting for sugar. But sugar just tends to give it too much of a boost.
After being low carb for a year or so, I would get an itchy fungal rash on my hand any time I ate the tiniest amount of sugar. Even a piece of fruit. It took years of drinking homemade kefir and eating more carbs for this to finally stop. I could have breezed through this (and not struggled with weight gain while my body readjusted to more carbs) so much faster if I had only known about RS.
carb sensitivity
How many people do you know who stayed very low carb for a long time, and can’t go back to carbs without gaining even more fat? More carb sensitive than before? This happened to me, and my A1Cs indicated that I was becoming pre-diabetic. I was clearly doing low-carb terribly wrong; meat, cheese, and whey protein shake based, with a few veggies once in a while, just at dinner. Not an optimal environment for my gut bug friends. How selfish of me. I was carb cycling but not with resistant-starch-rich foods, and not often enough.
the right keto/LC diet
So on a Keto/LC diet, can we keep our microbiota happy using resistant-starch-rich foods for our carb rations? Well, if you’re very focused on plenty of veggies at the core of your meals, the other types of fiber in all the greens do improve the effectiveness of the RS you do consume. FOS prebiotics can help RS work better too, but don’t come close to what RS can do on their own
Let me be clear that fiber will not do what RS does, so it does not replace our need for it.
Australia found this out the hard way when they increased their fiber hoping to reduce colon cancer and it did not work! They continued to have the highest colon cancer rates in the world. They eventually realized it was the resistant starch, not the fiber, that had the power to do such remarkable things.
Rural Native Africans eating a very basic diet high in resistant starch and low in dietary fiber have a colorectal cancer rate of less than 1 in 10,000. Australians eating a diet low in RS and high in dietary fiber have a colorectal cancer rate of 1 in 12.
Steele, Tim. The Potato Hack: Weight Loss Simplified (Kindle Locations 2313-2315). Kindle Edition.
low or no-carb sources of RS
As mentioned above, RS2 sources tend to be very low if not completely void of digestible carbs. For those who just don’t enjoy raw green bananas or raw potato slices, Bob’s Red Mill unmodified potato starch is a decent option for RS2. It’s insanely easy to mix in water or tea that’s below 130º.
I prefer to get everything I can from whole food but potato starch isn’t that processed. You can easily make it at home. And many of the studies showing benefits of RS use potato starch. I just like to get the plethora of other goodies that I learned about reading Tim’s book. I mean come on, there’s stuff in potatoes that reset hunger hormones!
Keep in mind RS2 and RS3 do different things, so I would be mindful of opportunities to get some higher carb RS3 in there as best you can. Just remember to cook, cool and reheat (or eat cold) to retrograde some of those starches. Roasted and cooled potatoes appear to be an awesome source.
definitive answer?
I would like to see some clear studies come out on gut health of people on a good vegetable-based (not vegetarian, just large portions of veggies with meat as a side) keto diet. The best would be a comparison of the microbiota of people on different variations of keto, paleo, intermittent fasting, etc. based on testing their gut flora. If you know of any studies or databases please comment and share.
I’m not ready to dismiss the possibility of having a healthy gut and healthy insulin responses on a keto/LC diet. There are people all over the world who seem to be benefiting when done with RS in mind. If you observe any symptoms that RS may resolve, perhaps that’s your indication that it’s time to re-evaluate.
Does resistant starch provide calories?
Yes. It is said to provide less than 2 calories per gram, which is half the calories of carbs. Some government agencies don’t even require the resistant starch portion of carbs to be labeled on packaged foods. If I’m understanding this right, those calories don’t come from the starch in the form of carbs, but rather from the byproducts of the bacteria that consume it so fat.
How to get resistant starch into your diet
Richard Nikoley, of freetheanimal.com, was kind enough to let me share his epic list of the RS content of many foods so you can compare how different methods of preparation affect the amount of RS left in the foods.
I was shocked to see how roasting potatoes appears to boost resistant starch way beyond the amount created by boiling. I had read a study that claimed moist heat created more RS, but I guess that’s not the case. Just when I think I have a handle on this there’s so much more to learn.
And by the way, keep in mind, some of the foods listed may not be the healthiest sources for RS, like potato chips or french fries, unless they’re homemade and cooked in healthy fats, of course.
My favorite ways to get RS are:
- re-heating roasted potatoes that have been in the fridge for many hours, ready for a post-workout meal with some eggs
- tossing some potato starch into some water or my raw goat’s milk, and drinking it down. You can bet I’ll be mixing it in my ice cream and porridge. shhh it will be our secret, although my husband does proofread my articles for me.😜
- eating green bananas (I know there will be haters and that’s ok 😉 there are so many options).
- hummus
- cold sushi – I’m talking refrigerated cold. Like grocery store sushi.
- home-dried plantain chips
- black beans
- raw potato slices. Don’t knock it till you try it. I find them very satisfying.
If you’ve signed up for my newsletter, there will be RS rich recipes heading your way from time to time!
How much?
Some people start taking 1/4 tsp. of raw potato starch to see if they tolerate it. Then they gradually add in different sources working up to a total of 20-40 grams per day.
Is it safe to eat raw potatoes or raw potato starch?
Mostly. Just don’t eat any green parts, eyes or sprouts which contain poisonous glycoalkaloids, of which the two most poisonous are solanine and chaconine. If your mouth feels scratchy or burns don’t do it. It’s probably been sitting on the store shelf too long. If you suspect you are sensitive to lectins and feel they are causing inflammation for you, it may be best to stick with getting RS2 from sources other than raw potatoes or raw potato starch. Cooking your potatoes reduces the lectins, but keep in mind frying can concentrate glycoalkaloids.
Cancer concerns?
Some controversy has sprung up about the possibility of certain types of RS causing cancer in some situations. Mark Sisson, of Mark’s Daily Apple posted this in response. I’ll just say Mark’s article along with reading some of Tim Steele’s comments throughout the interwebs has mostly allayed my concerns. But this article from thegutinstitute.com gives me reason to believe RS2 type starch should be avoided for people with a precancerous or cancerous colon. It sounds like once the gut lining is compromised enough, even the good butyric acid-producing bacteria, that feed on RS2, can get overgrown. Something to consider perhaps.
Is resistant starch for everyone?
Some people say that taking resistant starch is one way to find out if you have SIBO or other gut issues. They say if it causes excessive gas and bloating- there’s your indication. Many people are suggesting to start slow and work up to a higher dose. At first, this sounded plausible to me, but reading many people’s bad experiences with RS has convinced me that maybe it’s not that simple.
This article by Norm Robillard, another well-respected expert on RS, gives me reason to believe that caution should be exercised by those dealing with GI issues. When the gut is out of balance bad microbes can feed on RS too. Perhaps it would be wise to focus on foods rich in butyric acid while working on healing the gut, and transition into RS later.
nightshades
Potatoes should be off the table if you have an allergy, sensitivity or intolerance to them. There are plenty of other options out there for getting RS. Here’s that link again for the epic list of the RS content of many foods.
Troubleshooting
If you find you’re gaining weight eating RS rich foods, or you want to avoid making mistakes in the first place, here are some things to consider:
- Don’t mistake potato flour for potato starch. Huge difference.
- As Tim mentioned, high-pressure cooking can destroy RS. I’m so sorry fellow bean canning and Instant Pot friends. This is a disappointment for me too. It doesn’t sound like it reforms with cooling, but I’m not sure. As I learn more I’ll update you. Canned beans appear to have a small fraction of the RS of beans cooked without pressure and then refrigerated. Perhaps home canning doesn’t destroy as much as commercially canned beans? Maybe I’m grasping at straws in hope? I love having canned beans ready on the quick, but I may just go back to cooking and freezing to glean the most benefit.
- Cooking methods: It may be wise to check the list from time to time to make sure you’re using the best methods to maximize RS. I may just print it out to keep it handy.
- Remember the RS portion of food still provides calories in a roundabout way. It’s not much but still counts.
- Try to get RS3 but remember to use it wisely because this form does usually come with a lot of digestible carbs.
- Don’t fall for the recipes for making waffles and such with plantain or green banana flour unless you’re prepared to get much less RS and a lot more digestible starch. This isn’t always a bad thing if you’re prepared for the carbs because cooked plantains can still be a source of RS3.
- Pay attention to serving size. Potatoes can vary widely in size and carb count.
My experience so far
As I am about to publish this, it’s only been 3 weeks since I have been eating high RS foods as mentioned above, and occasionally taking Bob’s Red Mill potato starch. It has made a huge difference already! It seems to have fixed my circadian rhythms! I used to wake at 3 am every morning and now I’m sleeping through to 6 AM and finally feeling refreshed in the morning! Hello, clarity and motivation. I’ve missed you.
My belly is getting flatter, probably due to my newly found regularity. Sorry, but in this case, TMI is necessary evidence 😉 I’ve also noticed a huge drop in obsessive cravings for sugar. I’m ecstatic!
UPDATE: I’m going to get a little “Anne of Green Gables” on you here, but It is with deep sorrow that I will share with you that I ended up needing antibiotics for something serious. Normally I pull out all my herbal medicine concoctions or colloidal silver, but this time I had to be sure and hit it hard with a sure fist. I don’t take this lightly. Our gut bacteria have a lot to do with who we are on a very personal level. But ya’ know? This just might make what I’m about to share with you that much more intriguing.
Let’s test this out with a thermogram, shall we?!
Spoiler ALERT: Before adding resistant starch to my diet, I had a thermogram done as an alternative to a mammogram. The head to hip scan sounded good to me because I wanted to include my thyroid in the images. Shockingly, even with all the healthy things I eat and do, my gut was lighting up angrily! Not what I was expecting at all. But wow, God is good! I wouldn’t have even known my gut still needed serious work if I hadn’t been worried about my thyroid which prompted me to choose the more expensive scan. Thankfully my thyroid didn’t show any concerns that would have been picked up by thermography.
So… my big idea is that after I’ve had time to work on healing my gut with resistant starch (which may take many months now), I’ll show you my before and after scans of my guts! Don’t worry, it’s not graphic. But be sure to sign up for my free newsletter if you want to see if resistant starch can really be that powerful! Let’s be in this together.
More Questions
Something I haven’t seen many people talk about is that there is a type RS5. I came across this while reading this study on the benefits of RS, and this study on methods of increasing the resistant starch content of certain foods. Maybe someone with a higher pay grade can help me out. Does this mean adding fat to your mashed potatoes or rice creates even more RS? Would it behave the same way and still be accessible to good bacteria in the gut? Please comment if you have insight you’re willing to share with us.
So there you have it. 4 months of my life were put into this article. I hope you are now feeling the empowerment I felt as I learned that some of the limits I was putting on myself were actually harmful. I can’t wait to get out and plant potatoes!!!!
Thanks for visiting me here at Orange Grove Road! If you appreciate this article and want to help get the truth out there please share it.
Resources and Further Reading
Resistant Starch: Promise for Improving Human Health
Effects of resistant starch on the colon in healthy volunteers: possible implications for cancer prevention.Health properties of resistant starch
Health properties of resistant starch
Resistant starch consumption promotes lipid oxidation
How Resistant Starch Foods Can Help Our Thyroid Health
Is reheated pasta less fattening?
Cooked/Crystallized RS3 Trumps Raw RS2: They are Vastly Different for Our Guts
Free The Animal’s resistant starch food list
Dear Mark: Does Resistant Starch Cause Colon Cancer?
Resistant Starch – Friend or Foe?
Resistant Starch: Promise for Improving Human Health
Methodologies for Increasing the Resistant Starch Content of Food Starches: A Review
Great article! I’ve been researching RS for almost 10 years, I’ve not found a single shred of evidence that anyone should avoid it. However, when people get really bad gut dysbiosis (SIBO, GERD, IBS, etc…) they cannot often tolerate RS since their biome and gut lining is so compromised. Shame, but the people who need RS most cannot use it.
I like to think of RS as the best hedge against gut dysbiosis. When you are healthy is the best time to get started on it. RS’ effect on the immune system is immense. For people with gut problems, it’s best to go slow, get medical attention, and start to slowly increase the foods that make us healthy (fruits, veggies, unprocessed/whole foods).
I keep a jar of potato starch on the counter and add some to anything I’m making that it can be mixed into. Smoothies, ice cream, no-bake cookies, pudding, etc… As long as it’s not heated, it’ll work. Nearly every RS researcher I’ve ever talked to does the same, and that says a lot.
re: RS5 – RS5 is considered man-made like RS4, and developed to be included in processed foods to make them “healthier.” As you mentioned, several papers show that the RS of rice and pasta can be increased by stir-frying in oil. This observation is what led to the invention of RS5. But no need to buy RS5 fortified products, instead simply include stir-fried rice and potatoes, even plantains, using a healthy oil, in your normal line-up of meals. This is a little more involved than simply putting butter in mashed potatoes, the starches need to be heated considerably which causes retrogradation (staling) of the starch. This heat treatment makes the starch granules a sponge for the fats which bind with the newly created retrograde starch and make them resistant to digestion (RS).
It might all sound confusing, but getting RS into your diet is as easy as Liz says in her wonderful, comprehensive article.
Thank you for the insightful and kind response Tim! One of the reasons I got so into this article is that my mother has an ileostomy due to Crohn’s. I’ve been determined to have the healthiest gut I can have, and do the best I can for my family. We’ve been successful, mostly, however RS seems to be propelling us ahead. I’m hoping my mother will be able to tolerate it. At this point I’m not sure if it will do much other than help remove bad bugs since she only has a small intestine, but hey that alone is pretty amazing. You are so right. Prevention is key!
Great tip on having a jar on the counter to keep it handy. I think I see some no-bake cookies in my day tomorrow.
And thanks for helping us understand the RS5 better. Looking forward to adding some stir fry into the rotation.
Thanks for all you do and for the supportive words!
Hi Liz!
A lot of this makes great sense, but I’m trying to get all of it to mesh with my “traditional foods” mind. While some of it doesn’t seem like foods our ancestors would’ve cooked/eaten, some does, like re-heating roasted potatoes that have been in the fridge, black beans, hummus, and we do this one a lot: stir-fried rice or potatoes. But do those have to be cooked, cooled, and THEN stir-fried?
Just trying to get my brain around all of this!
Thanks Liz,
Kelly
Hi Kelly! It’s a lot to wrap my head around too. I agree, for instance, I doubt our ancestors would have consumed potato starch on it’s own. The other stuff in the potato does amazing things so I like to take advantage of the whole food. I believe that to be true of all foods.
But then again, I still appreciate healthy oils and butter which aren’t whole. Taking the RS straight has been the method of most of the studies showing all the benefits, however a couple of the links I mentioned give me pause. I think our ancestors would have gotten a variety of types of RS and probably not in isolation. It looks pretty clear to me that different types of RS feed different things in our guts.
To get RS3 type, the foods just need to be cooked and cooled, no stir frying is needed. If you want to reheat them it will further increase the RS by a little as long as you don’t use high heat or pressure. 400º is too high. To get RS5, the food would need to be cooked with fat at stir fry temps and cooled.
Beans are an awesome choice IMO, but just be careful not to do what I did. I thought our home canned beans fit the bill until I re-read the list of RS foods and their amounts. I’ll be going back to cooking and freezing. Bummer, but I want our food to do all that it can for us.
Thanks for the comment!
Liz