We’re working our way through butyrate and the foods that increase butyrate in the body. We are on resistant starch today. It’s a doozy. [“Doozy” probably comes from the nickname (“Duesy”) for a kind of car called a Duesenberg. It was a supreme, luxury car made in my home state of Indiana, in a tiny farming town called Auburn, north of Fort Wayne. Each Labor Day weekend they host a huge car auction called the Auburn Cord Duesenberg Festival.]
Don’t be afraid to let your diet be unique.
Getting butyrate and short chain fatty acids in the gut seems pretty important, and there a few dietary ways to go about getting it. No one way will work for every single person. You must recognize absolutely how unique and special you are. (Is this chick for real?) Seriously, I do think you’re probably pretty special, but I am talking about nutrition here. What makes one diet suitable for one person and detrimental to another? (Why can’t I eat ice cream? Whaaa-whaaa.)
- Your genetics: Yes. Absolutely. The genes we have will determine how well we can digest certain foods! If your long ago ancestors are from an area who relied traditionally on more starches, you have more genes to make amylase (the starch break-down enzyme) and more amylase in your spit. (1) Native Japanese people have genes to metabolize seaweed that people of European descent don’t. (Ha! For those who don’t like the flavor of seaweed, more power to ’em, eh?) (2) But, ice cream. Mmmm. Does ice cream make you bloat? Blame your genes’ inability to make lactase for you to break down the sugar in milk. (3) And your mix of genes will be different than your sister’s or cousin’s.
- Your gut bacteria. With the trillions (edited post-writing) of bacteria in your body, you’re bound to be one-of-a-kind. Some people will have more of one type of bacteria helping them eat than another kind. I hope over the butyrate series you have come to see bacteria as an integral part of you, your diet, and your health. Your bacteria will affect what you can comfortably eat or what happens when you eat it. If the bugs you happen to have are strains that make lots of methane with cellulose, then cellulose may not be your friend. Your bugs may do better with resistant starch. If you have significant overgrowths of putrefactive bacteria that make more toxic metabolites, maybe you’re at higher risk for disease from a high protein diet. (4) (5) (Studies show, however, that diet can modify levels of bacteria. So all is not lost!)
- Your individual function: We all have our own unique pathology. FODMAPS, SIBO, slow transit, food intolerances, and glucose intolerance just to name a few. If your small intestine is really bad at absorbing the sugars and sugar alcohols from foods (like in FODMAPS), you’re going to have to watch and keep a food diary to figure out which vegetables and fruits you can tolerate. If green bananas make you itch, you have to find another source for resistant starch.
Bottom line? Short chain fatty acids and butyrate are pretty darn important for the gut and body. Find a way to make your diet compatible with getting them. You have several options. For nearly any specialized diet, there is usually something you can tolerate to help boost needed nutrients.
Ok. Rant over– resistant starch to boost short chain fatty acid and butyrate production. This is going to be dry, dry, dry and long, long, long. I thought about dividing it up, but I wanted all the resistant starch stuff on one page, not several. And I figure those who actually read it are people really looking to learn about it– so they’ll like it on one page. By the way, Merry Christmas-time. I hope you are having a beautiful month. May you be filled with joy and peace now and forever.
Is that a healthy diet?
What healthy diet removes beans, legumes, grains and potatoes? When I began my food journey two years ago, I was SHOCKED to see grains and potatoes removed from many diets like Paleo, SCD, GAPS, Primal, and Whole30. (Were you shocked when you started?) However, after much research, I decided there was no harm in removing them as I tried to treat my GI health problems. I mean, my vegetable intake skyrocketed in compensation! Now, though, my GI issues have plateaued, and I have been on the prowl again to see what else can be done. I am tracking butyrate- producing foods. In this series, I have covered dairy products, fermented foods, fiber, and now we are hitting resistant starch.
Resistant starch from foods makes it past the small intestine’s digestive process to enter the colon, where bacteria can ferment (“eat it”) it to make short chain fatty acids and butyrate as a result. Great! Resistant starch is a popular topic in health spheres now. It has several possible health benefits. Do you see anything which could help you?
- Improved blood sugar control and insulin response to food. Implications for diabetes, pre-diabetes, and metabolic syndrome.
- Improved bowel health. Implications for colon cancer, ulcerative colitis, Crohn’s Disease, diverticulitis, and constipation.
- Improved cholesterol. Implications for heart disease, high cholesterol, and metabolic syndrome.
- Prebiotic to help stimulate the growth of “good” bacterial colonies in the colon.
- Control of hunger and reduction of calories eaten. Implications in obesity.
- Increased micronutrient absorption. Implications in overall mineral absorption for all and also in osteoporosis.
- Thermogenesis. Implications in diabetes and obesity.
- Synergistic interactions with other dietary components, e.g. dietary fibres, proteins, lipids. Implications for improvement of bowel health. (6)
The four ways to increase butyrate (as I see it) that I am working through:
- Eat butyrate-containing foods. (An aside: I found something that said there was a form of butyric acid in butter AND honey! The form is tributyrin, a form of butyric acid which is actually used in research studies to help the butyric acid not have such a short half-life. No quantities listed in the abstract. Isn’t that amazing? Whole foods really can provide for us!) (7)
- Eat butyrate-producing foods like fiber and resistant starch. (This is where we’re at in the series.)
- Take butyrate supplements.
- Take probiotics which contain bacteria known to make butyrate.
OK. Back to resistant starch. I know, some of you try not to eat starches. So what is the difference between starch and resistant starch? (Chemistry-wise, not much! Actions in the body, HUGE!)
What is starch? Starch is plant carbohydrate. A plant uses starch as a storage form for energy. Starch is high in things like potatoes, corn, rice, other grains, and beans. When we eat starch, it is usually completely broken down and absorbed in the small intestine by our amylase and other enzymes. You know the rest– glucose, insulin, and calories.
Let’s talk a minute about the structure of starch because structure is going to help explain what makes starch resistant. Starch is made up of two molecules, amylose and amylopectin. Both molecules are simply made up of many glucose molecules hooked together—just hooked in different ways. Amylose has many glucoses strung together in a tight, compact linear fashion. Amylopectin has glucoses strung together in branching chains, forming a large structure. Depending on the food/plant starch in question, these two players come together in different ratios and shapes. They connect with each other through hydrogen bonding and form crystalline granules (an important point here in a bit) of varying sizes. The crystalline granules are an effective way for the plant to store starch. We have an enzyme called amylase, which works in the small intestine, and it is most often able to break apart the bonds of starch to make simple sugars which are easily absorbed. (8, 9)
What is resistant starch? Same stuff as starch!!!! It’s just that for one reason or another (which we will talk about), it defies digestion by the small intestine and its amylase enzyme. It moves into the colon and feeds bacteria, thus producing short chain fatty acids and butyrate. Yeah!
How would the same stuff as plain, old starch do that? We will look at that in minute. First let’s mention the kinds of foods that have resistant starch.
What foods have resistant starch?
Obviously, starchy foods will have resistant starch, but how much resistant starch a food has– well, it will keep your head moving like one of those darn, tiny bouncy balls your kids like to throw around. Understanding resistant starch content is nearly insane. So I’m going to list some examples of resistant starch values, but you have to keep reading to understand how truly variable and FICKLE resistant starch is. For example, IT IS NOT ENOUGH TO SAY THAT A BANANA HAS LOTS OF RESISTANT STARCH—because sometimes it doesn’t! I started to put together a nice table of resistant starch values. I had research articles all over the schoolroom desk; I knew it was going to be a citation mess. Every source had different values for resistant starch content and often even for the same food. I decided making a chart was clearly was not a good time investment. (Where do you want to invest your time?) So here are some sources with lists of resistant starch contents for you to look over. For your information, some sources suggest at least 20 grams of resistant starch daily; others suggest more.
Free the Animal. Resistant Starch in Foods. (Man. What diligence. Kudos. This is what my table would have looked like. He did a great job, and I’m grateful for his work! This is a link to a PDF file which is featured on the blog.) (12)
8.5 grams/100 grams Raw green, medium-size
2.4-5.4 grams/100 grams Ripe, medium-size
12.2 grams/100 grams Boiled and stored at 5 degrees C –41 degrees F–fridge temperature
3.7 grams/100 grams Boiled and not cooled
50 grams per pound (Saw it on the internet gossip, but I need a legitimate source) (About 97% of the starch in raw potato is resistant.)
1.3 grams/100 grams Baked
Sweet potatoes (11)
1.1-2.1 grams Cooked
Raw About 98% of the raw starch is resistant. (Need source)
3.5 grams/100grams Cooked
Raw much, much higher (Need source)
Beans, white, boiled (10)
16.5 g/100 grams
Lentils, red, boiled (10)
13.83 g/100 grams
6.6 g/100 grams
0.2 g/100grams Cooked
7.8 grams/100 grams Raw
1.4 grams/100 grams Cooked whole wheat pasta (valemaisalimentos.com)
2.9 grams/100 grams Boiled 9 minutes (C)
Rice (11) (13)
3.1 grams/100grams White, cooked
1.6 grams per 1/2 cup Brown, cooked
The amount of resistant starch a food has will vary. It will vary by the TYPE of resistant starch, the food source of the resistant starch, the food preparation, and many other factors I will try to point out.
There are four types of resistant starch RS: Resistant starch type 1 (RS 1), resistant starch type 2 (RS 2), resistant starch type 3 (RS 3), and resistant starch type 4 (RS 4).
- RS 1 is in seeds, legumes, and whole grains. The starch is resistant because of the physical seed coat around the starch. (Grinding and milling will decrease the amount of resistant starch. Based on this, a wheat kernel has more resisant starch than ground flour. Even chewing your food well decreases RS!)
- RS 2 is in uncooked foods like potato, green banana, green plantains, sweet potato, cassava, yam, some legumes and high amylase corn. The natural, raw shape of the starch granules in these particular plants does not allow our digestive enzymes to get in and break down the starch. (5)
- RS 3 is in cooked and cooled starches, such as legumes, bread, cornflakes, potatoes, pasta salad or sushi rice. The starch when cooked becomes highly absorbable starch, but when it cools it forms a crystalline structure that won’t let enzymes in so it becomes resistant starch. This is called retrogradation. I will talk more about this below.
- RS 4 is chemically modified starch and is not naturally found in nature. It is often found in processed foods, but we don’t know if it acts the same as natural RS or not. (So why are they putting it in our foods? And why do people not care? Ignorance is bliss. But not really.) (6)
Both the plant species and the plant variety affects resistant starch content: Bananas overall have more resistant starch than most rice. Beans usually have more resistant starch than potatoes. Within a species, long grain rice has more RS than short grain rice. (14) Jasmine rice has less RS than long grain rice varieties. High amylose maize (corn) has been bred to have higher resistant starch than other corn.
Preparation method changes content of RS: Long grain rice prepared in a pressure cooker has less RS than when prepared in a traditional rice cooker. Baked potato has less resistant starch than potato salad. Heated and cooled, heated and cooled, heated and cooled potato has more resistant starch than just potato that has been heated and cooled one time only.
Cooking at all changes RS: Raw potato has immense amounts of RS. Mashed potatoes have immensely less.
Foods can have more than one kind of resistant starch: Potatoes have RS 2 when raw and RS 3 when cooked and cooled.
Ripeness decreases RS: A green banana has great amounts of RS. Ripe bananas have lots less.
Chewing decreases RS: What are you going to do about this one? LOL. I think this is a great example of how you can find good in just about everything! If you don’t chew well, you can get more resistant starch!
Remember how I mentioned amylose and amylopectin above? In part, their association together will help determine how much RS there is:
- Amylose and amylopectin come together in different ratios (maybe 20:80 or 40 :60 or 25:75) and will be different between species of plants and different varieties of the same plant, as I already mentioned. The more amylose there is, the more resistant. (5) In fact, there’s this processed stuff called High Amylose Maize Starch that was bred to have high amylose. It has great amounts of resistant starch. 1 tablespoon has 4.5 grams of resistant starch. (13) Amylose takes higher heats to gelatinize so it is more resistant. (When it gelatinizes, the body can digest it easier.)
- Chain length of the amylose and amylopectin molecules will affect resistant starch content.
- Size of the crystalline granules will affect resistant starch content. (15)
Non-starch components may affect the amount of resistant starch. Amylase (our digestive enzyme) can bind with fats, and then change the breakdown of the starch. If the amylase is all bound up, it’s not available to digest all of the starch. Some plants come included with their own amylase inhibitors so we digest them less, allowing more RS to the colon. Phosphorus can bind to the starch and make it more resistant.
Biological factors (such as transit time and menstrual cycles) can affect the digestion of starch. (6)
So when you look at different tables for resistant starch, you will see all kinds of different numbers. The resistant starch values will be all over the place. I know you don’t like it. It’s just the way it is. Nobody in life can give you an answer. We just have to do the best we can. God didn’t say, “Here. Eat resistant starch.” He gave you fresh vegetables, fruits, tubers, and yes, even grains. And thankfully, He gave me a fridge to cool my tubers.
Why in the world does cooling change the amount of resistant starch?
When typical starch is heated, it becomes quite absorbable. When it is cooled, it can form resistant starch and then not be absorbable. This is termed retrograded starch or resistant starch type 3 or RS 3. How does this happen?
Putting the starch in water and heating it allows the crystalline structure of the starch granules (made up of amylose and amylopectin) to swell. Water can get into the starch granules, but it can’t break them apart because of hydrogen bonding between amylose and amylopectin. The starch gelatinizes and swells. With the swelling comes increased ease of getting amylase into the starch to break down the bonds holding it together. So hot, cooked starch is easier to digest.
As the hot starch cools, its structure starts tightening back up and recrystallizing, becoming more like it was before water and heat was affected it. Amylase can no longer get in to break the starch down into absorbable sugars.
The higher the amylose content, the more heat that is needed to gelatinize the starch. Things with more amylose, such as high amylose corn starch, have more resistant starch. In one study, high amylose corn starch showed an increase in butyrate formation, whereas low amylose corn starch did not. (15) (16) (5)
People often wonder why it matters if it’s cooled since when it is eaten it heats back up in our bodies. I read that the answer to that is that it takes more heat than the temperature of your body to overcome the retrogradation.
Who might shy away from resistant starch?
SIBO people? People with small intestinal bowel overgrowth (SIBO) may have problems with resistant starch. (SIBO is a disorder which contributes to bloating, constipation, diarrhea, and stomach pain. It occurs when bacteria inappropriately colonize the small intestine.) I have seen the argument made that gastroesophageal reflux (GERD), SIBO, and some other GI disorders may be made worse by resistant starch. Increasing the food supply for the bacteria that are inappropriately growing in the small intestine doesn’t seem like it would be helpful. I can definitely understand this thought process. However, on the other hand, production of SCFA has been found to increase the motility of the gut and make the environment more acidic. These two mechanisms sound helpful! Everything is an equilibrium. Nobody right now knows the answer. This is where you drag out a pen and a calendar, and you diligently journal what you eat and your symptoms and stop waiting to be told what to do.
FODMAP people? One would think that FODMAP issues might actually do okay with resistant starch if there is no SIBO to go along and complicate the condition. The gases usually made by the bacteria from FODMAP ingredients are not formed from resistant starch: “However, RS [resistant starch] is believed to result in only a modest production of these gases [carbon dioxide, methane, hydrogen] compared with other non-digestible oligosaccharides, fructo-oligosaccharides and lactulose.” (6) Potato, sweet potato, and rice are often well tolerated in those with FODMAP issues–although I read that sweet potato has mannitol which may cause some people problems. (Sorry, no source.)
Diabetics: They say that diabetics’ blood sugars will be fine on resistant starch and may even improve! This seems like it would be quite variable and a diabetic should watch very closely. (19)
Flatulence: Excess gas. Anecdotal evidence points out that there is excess gas as a person starts increasing their resistant starch. The anecdotes say that it usually resolves in the first week at a stable dose.
Will resistant starch make me fat? Resistant starch reportedly helps with the feeling of being full–so you’re not so hungry! However, if it is metabolized by your bacteria, it does have calories (short chain fatty acids are made and absorbed). Typical starch that is absorbed up in the small intestine supplies 4.2 calories per gram. Apparently, resistant starch produces 2 calories per gram. (6) Want an anecdote? I started potato starch as a resistant starch. I stir one tablespoon in water twice a day. I can honestly say that I’m not very hungry. Of course, there could be a million and one other reasons for that.
Did you know we have a drug that makes starch resistant? Acarbose is a diabetic drug. It inhibits amylase and so increases the amount of resistant starch and also increases oligosaccharides. It has been found to increase SCFA in the colon (but with side effects of bloating, diarrhea, stomach pain, etc). (17)
Resistant starch versus non-starch polysaccharides (see last post for explanation) in butyrate production: RS seems to do a better job than other carbohydrates at producing butyrate. Resistant starch acts as a prebiotic, raising the numbers of lactobacilli and bifidobacteria. (5)
Resistant starch diet helps increase the neurons that promote motility: “After 14 days of RSD [resistant starch diet], the neurochemical phenotype of myenteric neurons of rats showed a significant increase of 35% in the proportion of ChAT-IR neurons complared with animals fed with the SD [standard diet]…As expected, RSD was associated with a significant increase in colonic concentration of butyrate compared with SD [standard diet].” (18) What is this saying? On a resistant starch diet, the proportion of acetylcholine neurons increased! Acetylcholine neurons play a large role in GI peristalsis and bowel movements. Also, my friend butyrate, was found at increased concentrations.
Which form of resistant starch produces more butyrate? This really seems to land you all over the place, trying to characterize all the different starch types and food types and how they each have a different effect. Crazy. Anyhow, RS 2 from raw potato starch is reported to increase the concentration of butyrate in humans and rats while RS 3 is reported to increase the concentration of acetate in pigs, but not in humans. (5)
Great related reading:
I’m not saying I agree with all that is said. I just like to see ALL that I can out there so I can think about how it applies to my body. Does benefit outweigh risk in trying something? Am I willing to accept that what somebody suggests could set me back significantly? Does what they’re saying make sense in the context of what I know about physiology and biochemistry (which is NEVER enough!).
Free the Animal has about a million resistant starch posts, including posts on specific conditions (like SIBO, FODMAPS, high blood sugars, etc.) This is really the place to go to read about resistant starch, although they have quite an enthusiastic stance. I’m pretty excited, too, but I try to temper my excitement. Nothing is a cure-all. I haven’t had success coming off of butyrate with an increase in resistant starch using green bananas and Bob’s Red Mill Potato Starch (yet).
Please take good care. Don’t be overwhelmed. Track your symptoms. Be patient with changes. Don’t get frustrated. Read. Weigh benefits and risks. Don’t flit from diet to diet to diet. Pick a system, stick with it awhile, and then implement tweaks slowly and methodically. Where you are at NOW does not reflect where you have to stay FOREVER!!!!!
As always, I need typos pointed out and faulty links. I do the best I can, but this is a simply a hobby of putting together my findings for others to read.
Diet and the evolution of human amylase gene copy number variation. Perry, Dominy, Claw, et al. Nature Genetics 39, 1256 – 1260 (2007) Published online: 9 September 2007. (Link)
Transfer of carbohydrate-active enzymes from marine bacteria to Japanese gut microbiota. Hehemann, Correc, Barbeyron, et al. Nature 464, 908-912 (8 April 2010). (Link)
Archaeology: The milk revolution. Curry, Andrew. Nature. July 2013. (Link)
Dominant and diet-responsive groups of bacteria within the human colonic microbiota. Walker, Ince, Duncan, et al. The ISME Journal (2011) 5, 220–230. (Link)
Starches, resistant starches, the gut microflora and human health. Bird, Brown, and Topping. Current Issues in Intestinal Microbiology. 2000. 1(1): 25-37. (Link)
Health properties of resistant starch. Nugent, AP. Nutrition Bulletin. March 2005. 30 (1): 27-54. (Link)
- (Abstract.) Anticarcinogenic actions of tributyrin, a butyric acid prodrug. Heidor, Ortega, de Conti, et al. Curr Drug Targets. December 2012. 13(14):1720-9. (Link to abstract.)
- The synthesis of the starch molecule. Smith, Denyer, et al. Plant Carbohydrate Biochemistry. 1999. Chapter 7.
- An in vitro method, based on chewing, to predict resistant starch content in foods allow parallel determination of potentially available starch and dietary fiber. Akerberg, Liljeberg, et al. The Journal of Nutrition. 1998. 128 (3): 651-660. (Link)
- The Resistant Starch Report. An Australian Update on health benefits, measurement, and daily intakes. Landon, Colyer, and Salman. Food Australia Supplement. 2012. (Link)
- Link to a PDF file on Free the Animal blog listing resistant starch content: http://freetheanimal.com/wp-content/uploads/2013/08/Resistant-Starch-in-Foods.pdf
- Natural Hi-Maize Starch website: “Double Resistant Starch Intake.” http://www.resistantstarch.com/NR/rdonlyres/DE2ADBB0-FF7D-40A7-B409-03493FEFFDFA/4601/Foodswithresistantstarch_LR.pdf
Effect of variety and cooking method on resistant starch content of white rice and subsequent postprandial glucose response and appetite in humans. Yu-Ting Chiu, Maria L Stewart. Asia Pac J Clin Nutr 2013;22 (3):372-379. (Link)
Understanding Starch Functionality. Scott Hegenbart. Food Product Design. January 1996. (Link)
Butyrylated starch increases colonic butyrate concentration but has limited effects on immunity in healthy physically active individuals. West, Shristophersen, et al. Exerc Immun Review. 2013. 19: 102-119. (Link)
Abstract for Effects of acarbose on fecal nutrients, colonic pH, and short-chain fatty acids and rectal proliferative indices. Holt et al. Metabolism. 1996. Sep;45(9):1179-87. (Link)
- Short-chain fatty acids regulate the enteric neurons adn control gastrointestinal motility in rats. Gastroenterology. May 2010. 138(5):1772-82. (Link)
Consumption of both resistant starch and b-glucan improves postprandial plasma glucose and insulin in women. Behall, Scholfield, et al. Diabetes Care. May 2006. 29(5): 976-981. (Link)