Resistant Starch

Resistant starch is “the sum of starch and products of starch degradation not absorbed in the small intestine of healthy individuals.”
Instead of being cleaved in twain by our enzymes and absorbed as glucose, resistant starch (RS) travels unscathed through the small intestine into the colon, where colonic gut flora metabolize it into short chain fatty acids. Thus, it’s resistant to digestion by the host.

It´s a type of starch that isn’t fully broken down and absorbed, but rather turned into short-chain fatty acids by intestinal bacteria.


There are four types of resistant starch:
RS Type 1 – Starch bound by indigestible plant cell walls; found in beans, grains, and seeds.

RS Type 2 – Starch that is intrinsically indigestible in the raw state due to its high amylose content; found in potatoes, bananas, plantains, type 2 RS becomes accessible upon heating.

RS Type 3 – Retrograded starch; when some starches have been cooked, cooling them (fridge or freezer) changes the structure and makes it more resistant to digestion; found in cooked and cooled potatoes, grains, and beans.

RS Type 4 – Industrial resistant starch; type 4 RS doesn’t occur naturally and has been chemically modified; commonly found in “hi-maize resistant starch.”


Where Do We Get It?
The richest food sources are raw potatoes, green bananas, plantains, cooked-and-cooled potatoes, cooked-and-cooled-rice, parboiled rice, and cooked-and-cooled legumes.

We can get RS from supplementary isolated starch sources. The best sources are raw potato starch, plantain flour, green banana flour, and cassava/tapioca starch. Raw (not sprouted) mung beans are a good source of RS, so mung bean starch (commonly available in Asian grocers) will probably work, too.


What Does It Do for Us?
Like any other organism, gut bacteria require sustenance. They need to eat, and certain food sources are better than others. In essence, RS is top-shelf food for your gut bugs. That’s the basic – and most important – function of RS.


What Are the Health Benefits of Consuming RS?
Preferentially feeds “good” bacteria responsible for butyrate production. It even promotes greater butyrate production than other prebiotics. Since the resident gut flora produce the butyrate, and everyone has different levels of the different flora, the degree of butyrate production varies according to the individual, but resistant starch consistently results in lots of butyrate across nearly every subject who consumes it. Butyrate is crucial because it’s the prime energy source of our colonic cells (almost as if they’re designed for steady exposure to butyrate!), and it may be responsible for most of the other RS-related benefits.

Benefits:
Improves insulin sensitivity.

The normal human gut has hundreds of bacterial species, some good and some not so good.  The overall number and relative quantity of each type has a profound effect on our health and well being.  Resistant starch selectively stimulates the good bacteria in our intestines, helping to maintain a healthy balance of bacteria.

Improves the integrity and function of the gut. Resistant starch basically increases colonic hypertrophy, making it more robust and improving its functionality. It also inhibits endotoxin from getting into circulation and reduces leaky gut, which could have positive ramifications on allergies and autoimmune conditions.

Lowers the blood glucose response to food. One reason some people avoid even minimal amounts of carbohydrate is the blood glucose response; theirs is too high.

Reduces fasting blood sugar.

Increases satiety.

May preferentially bind to and expel “bad” bacteria.

Enhances magnesium absorption.

It ups your calorie burn.

It can prevent cancer.  Research shows that the butyrate created by resistant starch may protect the lining of the colon, making it less vulnerable to the DNA damage that triggers diseases, such as colon cancer. It can also create a pH drop inside the colon, which boosts the absorption of calcium and blocks the absorption of cancer-causing substances.

It may fight diabetes and heart disease Like other fibers, resistant starch helps control blood sugar levels.

It boosts your immune system

By increasing the production of butyrate, resistant starch feeds the cells of the colon and leads to various improvements in the function of the digestive system.

Help prevent us from absorbing toxic/carcinogenic compounds.

Stimulates blood flow to the colon.

Increases nutrient circulation.

May help to lower blood cholesterol and fats, while also decreasing the production of new fat cells (the latter has only been shown in rats). Also, since SCFAs can inhibit the breakdown of carbohydrates in the liver, RS can increase the amount of fat we utilize for energy.

For those receiving treatment for cholera and/or diarrhea, RS can assist in the rehydration process (since it can normalize bowel function).