What You Need to Know About Commercially Made Resistant Starch

We’ve been talking about resistant starch for a while now, and if you’ve been following our series, you know that it’s a type of starch with several health benefits. There are many reasons to include foods containing it in your diet, from better digestive health and a healthy gut to improved insulin sensitivity for some people. 

As a refresher, remember that starches are chains of simple sugars that are linked together. They’re complex carbohydrates, broken down by your digestive system into simple sugars are released into your blood for your cells to use. There’s rapidly digestible, slowly digestible, and resistant starch. 

The two digestible starches are easier for the enzymes in your small intestine to digest. Your body breaks rapidly digestible starches down into sugars in a few minutes. Slowly digestible starches can take up to a few hours but are also fully broken down into sugars in the small intestine. On the other hand, resistant starches take much longer to digest. They are fermented in the colon by the bacteria that live there. So, resistant starches have a more complex structure that makes it harder for the enzymes in the small intestine to break down and end up in the colon where bacteria break it down. They also act as a probiotic for the bacteria that live there. 

A Refresher on the Types of Starch

We’ve also told you about the different types of resistant starch: RS1, RS2, RS3, and RS4. In case you need a quick recap:

• RS1 = physically protected (seeds)
• RS2 = resistant granules (bananas)
• RS3 = retrograded (cooked and cooled rice)
• RS4 = synthesized or man-made

If you don’t mind the texture of cooked and cooled potatoes, pasta, and rice, you may be interested to know that this process forms RS3, which may be less likely to cause blood glucose spikes. Reheating the cooled starches doesn’t make them easily digestible starches again. 

Once the structure has changed to make a starch harder to digest, there is no going back to the original. But if you need to avoid a particular type, finding substitutes is pretty straightforward. For example, you can substitute potato flour for refined wheat flour or vice versa. Resistant starches can also be synthesized to fit into more varied dietary needs. 

The tricky part sometimes, is finding out which foods suit your lifestyle and health goals, but a good way to do that is by monitoring how your body responds to different foods and types of resistant starch with a CGM. In this piece, we’re going to spend a little more time on RS4 or Resistant Starch Type 4.

More About Commercially Made Resistant Starches (RS4) 

Since we know where we can find them in nature and that you can also make them with processing or cooking techniques, let’s look a little deeper into RS4. You’ll usually find commercially made resistant starches in packaged foods, and you can identify them by their various brand names, including Hi-Maiz, Crysta-lean, Novelose, Fibersym, and Nutriose. Hi-Maize, for example, can be found in flour blends and vegan prebiotic shakes. It may appear on labels as high-amylose maize resistant starch. Many commercially made resistant starches are added to foods and marketed as a prebiotic because bacteria digest them in your large intestine.  

Making Resistant Starch Type 4

Several techniques are used to synthesize resistant starch, from heat to enzyme treatments, and sometimes a combination. Here’s a bit about each one:

• Heat Treatment: This technique involves cooking the starch at very high temperatures, drying it simultaneously, cooling it to room temperature, then freezing it overnight. The process is slightly similar to the cooking and cooling that makes RS3. This resistant starch is now available in bread, biscuits, and dairy products. Most of these starches come from corn starches. 
• Enzyme Treatment: This technique uses enzymes to break down the starch into starches of a specific length or specific branching structure to favor digestion in your colon. This process is becoming more popular because it is reported to be safer and potentially healthier than the chemical treatment or physical methods for making resistant starch. An example would be the use of enzyme treatment in resistant starch maltodextrin which is the combination of both heat and enzyme treatment (see below). This can be found in various food products that promise to be prebiotic. 
• Heat and Enzyme Treatment: With this technique, enzymes can produce starches that are more amenable to heating and cooling, reinforcing each other. Resistant maltodextrin is one example of a heat and enzyme-treated resistant starch as mentioned above. 
• Chemical Treatment: Here, starch molecules are linked to each other using a chemical reagent, making it more difficult for enzymes in your small intestine to digest them. 

It is important to differentiate this from modified food starch. Modified food starch is a native food starch that has been chemically or enzymatically altered to improve the texture or structure of food and is not the same as a resistant starch. However, modified food starches are not resistant starches. If you find it confusing, you are not alone. The major difference between the two types of starch is the structure of the starch and what it is used for in various products and how it is digested.  

Some Commercial Uses of Resistant Starch Type 4

As we mentioned above, these resistant starches can be found in various products and go by different brand names. They are typically added to products and touted as a prebiotic but may also have other qualities that might be favorable. Resistant starches are unusually well suited to use as dietary fiber in enriched bread. 

Other fiber supplements can negatively affect bread texture, color, and volume. Resistant starches can also favorably modify the texture of other baked goods, such as muffins. You can also use them to make waffles crispier and more moist as compared to other dietary fibers. When added in some proportion to cereals, they can also enhance the flake size of your cereal!

Why are we so interested in resistant starch? It’s because of their potential to increase satiety and improve insulin sensitivity. Resistant starches may also have a role in glucose management since they often have low glycemic index values. It doesn’t seem to matter how we make resistant starches, although research is still ongoing here. Since synthetic resistant starches (RS4) have several favorable effects, including improving the crispness, texture, and volume of food, they’re a good option overall. 

Because of how slowly your body digests them and the involvement of large intestinal bacteria fermentation support, these starches may be better for people watching their glucose. But since people can react differently to the same foods, it may be best to experiment with adding resistant starches to your diet with a continuous glucose monitor (CGM). It’s also a good idea not to make any drastic changes to your diet without checking with a healthcare professional.