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A New Superfood? The Truth About Resistant Starch
A New Superfood? The Truth About Resistant Starch
I hope this finds you better than ever.
Resistant starch is all the rage on the nutritional front line at the moment.
Touted as a new cure for everything from sleeplessness to improving blood sugar, I thought it was high time we share some insights about this puppy.
We thought we’d figured out dietary fiber. We really did. We believed there were only two basic types:
- Soluble, fermentable fiber, which is good for your gut and a lot of other things.
- Insoluble, non-fermentable fiber, which isn’t so good for your gut, especially if you have digestive issues.
Though this is still good, basic advice, there’s a new kid on the block that deserves your attention. It’s called resistant starch.
Researched in the 1980’s, until recently, most experts categorized resistant starch as an insoluble fiber because it can’t be digested in the small intestine. But an increasing body of evidence suggests that resistant starch is neither a soluble nor insoluble fiber, but a distinct type of fiber that has its own unique effects and health benefits.
For that reason, many experts have started referring to resistant starch as the “third” type of dietary fiber. In the Paleo or evolutionary health community, many leading proponents of the primal lifestyle are admitting that they previously underestimated resistant starch and are urging their followers to eat more of it.
I’ll do my best to avoid adding any more confusion to what is already a confusing topic, and cut straight to the question I got asked the last four hundred times I mentioned resistant starch.
Kiwi, What the Heck Is Resistant Starch?
Personal questions, mate, personal questions
Resistant starch is found in a variety of foods, both gut-friendly and gut (or paleo)-unfriendly. It’s called “resistant” because it resists digestion in the small intestine. In that sense, it’s similar to insoluble fiber, which also passes intact through the small intestine.
Unlike insoluble fiber, however, resistant starch doesn’t stay intact all the way through the large intestine and into the toilet.
Once it reaches the large intestine, it is fermented by the resident bacteria and transformed into substances called short-chain fatty acids.
You will learn more about these dietary superheroes in a momentIt also produces gases such as carbon dioxide, methane, hydrogen, but it modest amounts compared to other non-digestible oligosaccharides, fructo-oligosaccharides and lactulose.
Because resistant starch can be fermented, it’s similar to soluble fiber, but only superficially.
Unlike soluble fiber, resistant starch can’t be dissolved in water (the definition of “soluble,” right?). Another important difference is that soluble fiber is fermented in the small intestine, by a completely different group of resident bacteria which don’t produce near as many wondrous short-chain fatty acids.
Resistant starch is also a different beast than regular starch.
Regular starch contains higher amounts of a sugar molecule called amylopectin. Because amylopectin is what scientists call “highly branched,” it has more surface area exposed to the digestive enzyme amylase.
So most regular starch is rapidly digested into glucose, which can cause nasty spikes in blood sugar.
This is bad in most people, especially fat or metabolically deranged ones.
In contrast, resistant starch contains higher amounts of a sugar molecule called amylose.
Because amylose is what scientists call a “straight chain,” it has relatively little surface area exposed to the digestive enzyme amylase. That’s how resistant starch is able to avoid digestion until it reaches the large intestine, where it falls into the clutches of amylose-hungry bacteria such as Bifidobacterium, Clostridium, and Bacteriodes.
Because this is a relatively slow process, resistant starch does not cause unwanted increases in blood sugar. It also provides fewer calories than regular starch: only 2 calories per gram versus 4 calories per gram.
“And there is the nature of the potential magic of resistant starch: it survives long enough to make it to the large intestine INTACT – creating a buffet for rapid bacterial growth, right where you want them – without messing with blood sugar”
Which Foods Contain Resistant Starch?
During the Paleolithic era, it’s estimated that our ancestors consumed up to 135 grams per day of a mix of “good” fiber in the form of resistant starch and other fermentable fibers (soluble starch). They did so by feasting on bulbs, corms, and tubers such as potatoes, sweet potatoes, and yams which they could dig up as they roamed. But their sources also included foods that most of us would consider yucky, such as cattails, cacti, and bark.
Today, the most common sources of resistant starch include Kiwi -friendly foods such as peeled white potatoes, especially those that have been cooked and cooled. (The cooling process transforms regular starch back into resistant starch.)
Other gut-friendly sources include palatable foods such as potato starch, plantain flour, tapioca flour; and some maybe not-so-palatable foods such as uncooked potatoes, green bananas, and raw plantains.
Unfortunately, other common sources of resistant starch include gut-unfriendly foods such as grains, most legumes, and even some types of bread that have been frozen for 30 days.
Obviously, this poses a dilemma for people who take my recommendations to avoid grains and legumes (which contain gut-damaging substances such as gluten, lectins, and anti nutrients such as phytic acid) and prefer to eat their potatoes cooked and warm.
If you’re following a a Chris the Kiwi paleo template lifestyle, (and you SHOULD BE!) particularly if you are in a RESET and/or eating predominantly low carbohydrate for an extended period of time due to insulin management – you may be missing out on the health benefits of resistant starch.
Even if you don’t, odds are you’re not getting enough resistant starch.
In developed countries such as the United States, England, and Germany, the average daily intake of resistant starch is only 3-9 grams per day compared to 30-40 grams per day in developing countries where diets are often based on whole plant foods.
According to what we could find in scientific studies, the health benefits of resistant starch don’t really kick in until you consume about 20-40 grams per day.
Although some anecdotal benefits have been seen from as low as 4 grams a day, it looks like you need to dose up over time.
If you’re unwilling to eat raw potatoes and green bananas, a mountain of cooked and cooled potatoes, let alone being silly enough to take your chances on grains and legumes, probably the easiest way to get the ideal quota of resistant starch is potato starch or one of the milled starches of foods such as green plantains or green bananas.
Across the Internet, people playing with resistant starch are recommending Bob’s Red Mill unmodified potato starch, which you can buy very cheaply online here on amazon
Bob’s Red Mill Potato starch <—– click here
I met Bob and his team at the recent Natwest Expo in Anaheim. He impressed me with his dedication to keeping impurities out of his gluten free line.
My sister Liana took her photo with him, because, well, he is the Bob. I digress.
Liana and Red Mill Bob earlier this month:
It is extremely cheap, and very much gluten free.
Potato starch has no real taste, and can be mixed in any liquid including warm (but not hot) coffee. Some folks like to mix it in yogurt. Others like to add it to luke warm soups or broths.
Potato starch doesn’t become gritty, mealy, or pasty. Just be sure you don’t heat it to 160 or more because that will turn the resistant starch into regular starch.
Each tablespoon of potato starch contains about 8 grams of resistant starch. Anecdotal reports suggest that 4 tablespoons per day have a beneficial effect on gut health and also help reduce LDL “bad” cholesterol, triglycerides, and blood sugar while boosting HDL “good” cholesterol.
WARNING: if you have ANY form of IBS, FODMAP intolerance or have never before tried a concentrated form of resistant starch then YOU MUST, MUST, MUST start with an extremely low dose.
I would recommend “normal” folks experiment with one teaspoon, mixed in cold or luke warm water, a few hours before bed.
I would recommend anyone with IBS or FODMAP intolerance to utilize extreme caution, and begin with only a quarter or half a teaspoon.
Increase dose after a week.
Those with auto immune conditions or who do not react well to potato should skip the potato starch and look for another form of resistant starch.
Kiwi Approved Natural Sources of Resistant Starch
White potato starch (NOT FLOUR)
Green banana flour (which is actually starch)
Green plantain flour (which is actually starch)
Tapioca flour (which is actually starch)
Just make sure that they are gluten free, as many mills will not be running only “good” starches through their mill, capiche?
You can EAT any of those items as well. If you are friends with any latin folks from the Caribbean, ask them to cook you some fried green plantains in coconut oil.
I have been eating a banana as green as I can take it post work out. I feel pretty good on this.
A further alternative if you tolerate the rice is cooked and cooled sushi rice, which contains about 5 grams of resistant starch per cup. As I don’t tolerate rice well, this is typically a cheat meal day only option for me.
Why Is Resistant Starch So Healthy? Let’s talk superheroes
Fermentable fiber such as resistant starch is especially important because it is digested by bacteria to produce short-chain fatty acids such as acetate, propionate, and butyrate, which provide many health benefits.
Of all the short-chain fatty acids produced by the digestion of resistant starch, butyrate may be the most significant. Although other fermentable fibers produce butyrate, resistant starch produces the most significant amount.
What’s so special about butyrate? For starters, it is the energy source of choice for the epithelial cells lining your large intestine. When bacteria convert resistant starch into short-chain fatty acids, it can improve your food mileage by a WHOPPING 30 percent.
In addition, scientific studies suggest that butyrate can improve wound healing and reduce inflammation in the gut, with beneficial effects on the epithelial and mucosal cells.
Butyrate reduces gut pH levels. It also appears to promote the death of damaged cells (apoptosis), which may explain the correlation observed in large epidemiological studies between intake of dietary fiber and reduced colorectal cancer.
A lack of short chain fatty acids, leading to starvation of the epithelial cells of the colon wall, has been proposed as a potential cause of ulcerative colitis and other inflammatory conditions.
What Are the Health Benefits of Resistant Starch?
Research suggests that resistant starch is associated with the following benefits:
- Increased absorption of minerals, especially calcium and magnesium.
- Improved insulin sensitivity. In what is known as the “second meal effect,” it also improves glucose tolerance the next day.
- Increased satiety, which may help overweight and obese people lose weight. Short-chain fatty acids also can trigger the release of appetite-suppressing hormones such as leptin.
- Decreased levels of cholesterol and triglycerides.
- Promotion of “good” bacteria and suppression of “bad” bacteria and their toxic products.
- Improved bowel regularity.
- Less fat storage after eating meals that include resistant starch.
- Improved sleep quality
- Stimulation of blood flow to the large intestine.
- Reduced risk of colon cancer and inflammatory bowel disease.
- Enhanced immunity.
- Improved digestion, which may help alleviate conditions such as inflammatory bowel disease, irritable bowel syndrome, constipation, and diverticulitis.
Summary: Resistant starch, a “new” type of fiber, may represent a major next step in our understand of how to optimize our personal gut biome (the good bacteria) that are so important for excellent health.
I recommend you experiment with it, and tell me how you get on.
Remember, start slowly. Some people report excessive flatulence and gas when they first start consuming resistant starch, others report cramping.
Give Bob’s Red Mill Potato Starch a shot —- click here for Amazon link.
You can buy in single 24 oz packs, or packs of four. These are available on amazon via the link above or in a growing number of health foods stores.
Of important note, is that you may want to consider consuming more probiotic foods for a period of time, prior to beginning your resistant starch protocol.
The rational: put some good bacteria in there (eating fermented foods and probiotics) before you lead them to the feeding trough to grow them (adding resistant starch to your diet).
For fermented foods, I like raw kim chee and sauerkraut, you can also go with coconut kefir (non dairy) and with dairy kefir and yogurt if you tolerate the dairy.
Beyond your daily serving of Athletic Greens, I recommend you add two tablespoons a day of sauerkraut or kim chee to two of your meals, for a week or two before starting your resistant starch experiment.
And that is just what it should be, an experiment. There is no one size fits all for this one.
Let me know how you get on. Please leave your comments below on the blog.
“100% Focus on Happiness”
That is my mantra, and it starts with phenomenal health.
Chris “the Kiwi”
1. Up To Date: “Patient Information: “High-fiber diet (beyond the basics).” http://www.uptodate.com/contents/high-fiber-diet-beyond-the-basics?view=print
2. Linus Pauling Institute
Micronutrient Information Center: “Fiber.” http://lpi.oregonstate.edu/infocenter/phytochemicals/fiber/
3. Rao AV, et al. Effect of fiber-rich foods on the composition of intestinal microflora. Nutrition Research. Volume 14, Issue 4, April 1994, Pages 523.-535. http://www.sciencedirect.com/science/article/pii/S0271531705802167
4. Threapleton DE, et al. Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ, 2013; 347 doi: http://dx.doi.org/10.1136/bmj.f6879 (Published 19 December 2013) http://www.bmj.com/content/347/bmj.f6879
5. Aune D, et al. Dietary fiber and breast cancer risk: A systematic review and meta-analysis of prospective studies. Ann Oncol (2012) 23 (6): 1394-1402. doi: 10.1093/annonc/mdr589 First published online: January 10, 2012 http://annonc.oxfordjournals.org/content/23/6/1394.long
6. Romieu, I et al. Carbohydrates and the risk of breast cancer among Mexican women. Cancer Epidemiol Biomarkers Prev. 2004 Aug;13(8):1283-9. PMID:15298947 [PubMed - indexed for MEDLINE] http://www.ncbi.nlm.nih.gov/pubmed/15298947
7. Nugent AP. (2005), Health properties of resistant starch. Nutrition Bulletin, 30: 27–54. doi: 10.1111/j.1467-3010.2005.00481.x
8. Maki KC, et al. Resistant Starch from High-Amylose Maize Increases Insulin Sensitivity in Overweight and Obese Men. J. Nutr. April 1, 2012 vol. 142 no. 4 717-723. First published February 22, 2012, doi: 10.3945/jn.111.152975 http://jn.nutrition.org/content/142/4/717.long
9. Maziarz, MP. Role of Fructans and Resistant Starch in Diabetes Care. Diabetes Spectrum February 2013 vol. 26 no. 1 35-39 doi: 10.2337/diaspect.26.1.35 http://spectrum.diabetesjournals.org/content/26/1/35.full
10. Furusawa Y, et al. Commensal microbe-derived butyrate induces the differentiation of colonic regulatory T cells. Nature 2013 Dec 19;504(7480):446-50. doi: 10.1038/nature12721. Epub 2013 Nov 13.
11. Cummings JH, et al. Prebiotic digestion and fermentation. Am J Clin Nutr. 2001 Feb;73(2 Suppl):415S-420S. http://www.ncbi.nlm.nih.gov/pubmed/11157351
12. Wong JM, et al. Colonic health: fermentation and short chain fatty acids. J Clin Gastroenterol 2006 Mar;40(3);235-43. http://www.ncbi.nlm.nih.gov/pubmed/16633129
13. Lanza E, et al. The polyp prevention trial continued follow-up study: no effect of a low-fat, high-fiber, high-fruit, and -vegetable diet on adenoma recurrence eight years after randomization. Cancer Epidemiol Biomarkers Prev. 2007 Sep;16(9):1745-52.
14. Tan KY, et al. Fiber and colorectal diseases: separating fact from fiction. World J Gastroenterol. 2007 Aug 21;13(31):4161-7. http://www.ncbi.nlm.nih.gov/pubmed/?term=17696243
15. Peery AF, et al. A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis. Gastroenterology
Volume 142, Issue 2 , Pages 266-272.e1, February 2012. http://www.gastrojournal.org/article/S0016-5085(11)01509-5/fulltext
16. Harvard University Health Services: “Fiber Content of Foods in Common Portions.” May 2004. “http://huhs.harvard.edu/assets/File/OurServices/Service_Nutrition_Fiber.pdf
17. Tufts University: “Fiber Content of Selected Foods (Source USDA).” http://ocw.tufts.edu/data/47/531408.pdf
18. Human Food Project: Sorry low carbers, your microbiome is just not that into you. http://humanfoodproject.com/sorry-low-carbers-your-microbiome-is-just-not-that-into-you/
19. HealthCastle.com: “The Potential Benefits of Resistant Starch”
20. Digestive Health Institute: “Resistant Starch: Friend or Foe?” http://digestivehealthinstitute.org/2013/05/10/resistant-starch-friend-or-foe/#_edn5
21. Weikel, K. A.; Fitzgerald, P.; Shang, F.; Caceres, M. A.; Bian, Q.; Handa, J. T.; Stitt, A. W.; Taylor, A. (2011). “Natural History of Age-Related Retinal Lesions that Precede AMD in Mice Fed High or Low Glycemic Index Diets”. Investigative Ophthalmology & Visual Science 53 (2): 622. doi: http://www.iovs.org/content/53/2/622
22. Uchiki T, Weikel KA, Jiao W, Shang F, Caceres A, Pawlak D, Handa JT, Brownlee M, Nagaraj R, Taylor A. (2012). “Glycation-altered preolysis as a pathobiologic mechanism that links dietary glycemic index, aging, and age-related disease (in nondiabetics)”. Aging Cell 11 (1): 1–13. doi:10.1111/j.1474-9726.2011.00752.x. PMC 3257376. PMID 21967227 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257376/