Understanding resistant starch is not hard once you compare it to what you already know about starches. We know that the starch that we eat is digested at different rates. How do I get it and what are the benefits of resistant starch? The starch in potatoes, cereals, and baked goods digests very rapidly, but other starchy foods, like beans, barley, or long grained brown rice, are digested more slowly and cause a much slower and lower blood sugar rise.

Resistant starch actually goes all the way through the small intestine without being digested at all. So in fact we may say it ‘resists’ digestion, hence the name. In this way, it is more like fiber, and in some cases is classified and labeled as a component in dietary fiber.

Once the starch reaches the large bowel, it provides fuel for the microbiome or resident bacteria, which break it down (ferment) to produce Butyrate, which keeps the gut in a healthy functional state. Butyrate lines the gut wall and keeps the integrity of the wall that helps support a healthy digestive system and protect against gut and other digestive diseases.

So resistant starch is vital to maintaining a healthy gut microbiome, but may also offer other health benefits such as helping to reduce your risk of type 2 diabetes by increasing the body’s sensitivity to insulin.

So what makes some starch resistant?

There are four types:

1. Starch that is difficult for the digestive process to reach, often due to a fibrous “shell”. Grains and legumes which are cooked intact are an example. Also, some altered starches, such as Hi-Maize corn starch, are in both this category and the next.
    
2. Some foods, such as unripe bananas, raw potatoes, and plantains, have a type of starch which our digestive enzymes can’t break down.
    
3. Small amounts of resistant starch (about 5% of the total) are produced when some starchy cooked foods, such as potatoes and rice, are allowed to cool before eating.
    
4. Manufactured resistant starch, made by various chemical processes. It is not known whether these starches have the same benefits as those in the other three groups.

Most starchy foods have at least a small amount of resistant starch in them.

What are the benefits of resistant starch?

It seems that the more it is studied, the more positive effects are being found. Here are some of the benefits of resistant starch:

• Resistant starch is especially associated with one type of SCFA, called butyrate, which is protective of colon cells and associated with less genetic damage (which can lead to cancer).
• As with other fermentable fiber, resistant starch is associated with more mineral absorption, especially calcium and magnesium.
• Perhaps most exciting for people with sugar issues, resistant starch seems to improve insulin sensitivity.  In the so-called “second meal effect”, fermentable fiber and resistant starch are associated with improved glucose tolerance the next day. 
• It produces more satiety.
• Good consumption is associated with lower cholesterol and triglyceride levels.
• Promotes “good” bacteria, and supresses “bad” bacteria and their toxic products.
• Promotes bowel regularity.
• Good content in a meal is associated with less fat storage after that meal.

How do I get resistant starch in my diet?

All starchy foods contain some resistant starch. The best sources are wholegrain cereals and legumes. Naturally occurring in cereal foods, such as breads and pasta, and legumes for example lentils, chickpeas, red kidney beans and baked beans, nuts and some seeds, starchy vegetables, and firm bananas.

The amount will vary depending on how food is manufactured, prepared and cooked – and if it has been reheated.

Generally speaking, processing and heating starchy foods depletes their resistant starch content; the more severe the conditions, the lower the resistant starch. But resistant starch also can be formed when cooked foods are cooled. Repeated cooking and cooling produces a modest rise in resistant starch levels of foods such as cold cooked rice, pasta and potatoes.

How much should I be Consuming?

Eating roughly 15-20 grams of resistant starch per day is recommended for good bowel health. The typical Australian diet currently is nowhere near this estimated at only 3 – 9 grams per day. This is not completely accurate though as it is not something that is monitored well.

_Source

_{Brighenti, Furio et al. “Colonic fermentation of indigestible carbohydrates contributes to the second-meal effect.” American Journal of Clinical Nutrition 83.4 (2006): 817-822.}

_{Cummings, JH. “The Large Intestine in Nutrition and Disease: (monograph), December 1996, ISBN 2-930151-02-1}

_{Englyst, Klaus and Englyst, Hans. “Carbohydrate Bioavailability.” British Journal of Nutrition94 (2005): 1-11.}

_{Englyst, Klaus, et al. “Glycaemic index of cereal products explained by their content of rapidly and slowly available glucose.” British Journal of Nutrition. 89 (2003):329-339}

_{Higgins, Janine. “Resistant Starch: Metabolic Effects and Potential Health Benefits.” Journal of AOAC International 87 (2004):761-8.}

_{Higgins, Janine, et al. “Resistant starch consumption promotes lipid oxidation.” Nutrition and Metabolism 1.8 (2004): 1743-7075.}

_{Robertson, M.D. et al. “Prior Short-Term Consumption of Resistant Starch Enhances Postprandial Insulin Sensitivity in Healthy Subjects.” Diabetologia 46 (2003): 659-665.}