In This Article
Good Carbs Do Exist
In past articles, I have mentioned that ancient humans gobbled down up to five times as much fiber as the average American eats today. Fiber has many benefits, one of which is to feed the microbes in the colon that are critical for our immune and cognitive health, among other things.
I have also commented on the fact that ancient humans ate about the same amount of carbohydrates as we do, although much less of it was in the form of sugar as compared to the modern diet.
One of the ways ancient humans got both their starch and their fiber in one go was by eating a certain class of starches, sometimes called “prebiotic fiber” or Resistant Starch (RS).
In this week’s article, we’ll discover this much-overlooked food group that holds within its potential the ability to help us take significant strides towards stronger immunity, great elimination, digestive health, healthy blood sugar and our optimal weight.
The Third Type of Fiber
Resistant starches are considered a third type of fiber. We have soluble fibers like flax, chia and oats that break down into an intestinal slime that soothes the digestive tract and slows the absorption of sugars into the bloodstream while feeding the microbes that line the intestinal wall.
Then there is insoluble fiber or roughage – like leafy greens and vegetable cellulose – that doesn’t break down in the digestive system but acts as feed for the microbiology. These are the same microbes that do the heavy lifting for practically every function in the body.
Resistant Starches (RS) are starches that resist being broken down or digested by the acids and enzymes in the stomach, gallbladder and pancreas. (3) But unlike fiber, which also is resistant to the digestive process, resistant starches are long chains of glucose that make it all the way through the digestive process intact to the large intestine where they feed the microbes, acting as one of nature’s most effective pre-biotics. (5)
A pre-biotic is defined as an indigestible carbohydrate that stimulates the growth and maintenance of beneficial gut microbiota. Quite simply, it is the fuel that your beneficial gut microbes need to thrive.
Probiotics are the good bacteria themselves, which are very important. But without adequate fuel, these probiotics may not proliferate and maintain their residence in the gut as we would like them to for optimal health.
Boost Your Intestinal Health and Immunity
These resistant starches have been studied to be particularly beneficial for the production of a short-chain fatty acid in the gut called butyrate. (1) Remember, butyrate is the fatty acid that got its name from butter, the source in which it was originally found. Ghee, the Indian variation of clarified butter that is used in Ayurveda to cleanse, heal and nourish the digestive system, is the richest food source of butyrate on the planet.
Butyrates in the gut have been studied to be the preferred fuel supply for the colon cells, and the primary fatty acid that supports intestinal immunity, which experts believe accounts for 80% of the body’s entire immune system. (2) These fatty acids also play a key role in protecting the intestinal tract from undesirable cellular proliferation. (11)
Enjoy Great Elimination
Resistant starches also provide a natural bulking agent that supports healthy elimination without holding onto water the way certain fibers and magnesium do. (4) As pre-biotics, the resistant starches feed the microbiology in and naturally reduce the Ph of the colon, protecting it from harmful and irritating bacteria and digestive by-products.
Promote Healthy Blood Sugar
In one study, a group of overweight men ate 15 grams of RS a day and improved insulin sensitivity by a whopping 50% (8), which is bolstered by a decreased glycemic response observed in healthy individuals with the addition of dietary RS in another study. (9)
Support Optimal Weight
RS supports optimal weight balancing in numerous ways. Like most fibers, it delivers a sense of fullness and facilitates a naturally calorie-restricted diet. It also doesn’t allow its sugar to enter the bloodstream, therefore limiting excess sugar in the blood being stored as fat. In fact, RS has been shown to help the body naturally burn fat. (10)
So – Where Do You Get It?
There are four types of resistant starches (RS):
RS1: Digestion-resistant starch, such as that found in seeds or legumes and unprocessed whole grains.
RS2: Resistant starch such as uncooked potato, green banana flour and high amylose corn starch.
RS3: Resistant starch that is formed when starch-containing foods are cooked and cooled, such as that found in legumes, bread, cornflakes and cooked-and-chilled potatoes, pasta salad or sushi rice. In this process, starches become less digestible after being heated, dissolved in water and then cooled, converting to RS’s. (6)
RS4: Starches that have been chemically modified to resist digestion. These types of RS can have a wide variety of structures and are not found in nature.
The major food sources of Resistant Starches are: (7)
|Food||Serving Size||Amount of Resistant Starch (grams)|
|Banana, green||1 medium, peeled||4.7|
|High amylose corn starch||1 tablespoon||4.5|
|Oats, Rolled||¼ cup, uncooked||4.4|
|Green Peas, frozen||1 cup, cooked||4.0|
|White beans||½ cup, cooked||3.7|
|Lentils||½ cup, cooked||2.5|
|Cold-Cooked Pasta||1 cup||1.9|
|Pearled Barley||½ cup, cooked||1.6|
|Cold Potato||½” diameter||0.6 – 0.8|
|Oatmeal||1 cup cooked||0.5|
Take this Fiber Home with You
As support for healthy blood sugar, a more diverse population of microbes in the gut, better immunity and intestinal health, consider making some of these foods a regular part of your diet. For best results, try and get about 15 grams of RS a day.
- European Journal of Clinical Nutrition 46 (Suppl 2): S1–148. PMID 1425538.
- Am J Clin Nutr 2001;73(2 suppl): 415S-20S. PubMed 11157351
- American Journal of Clinical Nutrition, 1995; 62, 121-130. http://www.ajcn.org/cgi/content/abstract/62/1/121
- Int J Food Sci Nutr. 60 Suppl 4: 258–72. doi:10.1080/09637480902970975. PMID
- Am. J. Clin. Nutr. 72 (2): 432–8. PMID 10919938.
- Nutr Metab (Lond) 1 (1): 8. doi:10.1186/1743-7075-1-8. PMC 526391. PMID 15507129.11. Mutat. Res. 682 (1): 39–53. doi:10.1016/j.mrrev.2009.04.001. PMID 19383551.