Skip to main content

The word ‘starch’ conjures up the worst images.

When we think of starch, we tend to think of cake. White bread. Pasta.

And we forget about whole grains, legumes, and tubers.

Doesn’t all that starch just make you FAT? Isn’t it downright unhealthy?

Nothing could be farther from the truth.

There’s much more to starch than meets the eye.

Not only do we all need starches in our diet—but consumed from the right sources—nothing could be better for us. Starch is the most plentiful carbohydrate found in plant foods and it’s the major source of energy for humans. And until you realize that starches are good for you—and that much of your diet should come from them—you will continue to struggle with many of your health and weight issues.

Today I’d like to tell you about a very specific starch—resistant starch—which can be very important to your health.

Fiber, Resistant Starches and How It All Works

Resistant Starch is a type of fiber. It is considered one of the three classes of dietary fiber along with the well-known insoluble and soluble fibers. Here’s a description of each:

  • Resistant Starch resists breakdown in the stomach and small intestine, arriving to the large intestine intact. When it arrives in the large intestine, resistant starch acts as ‘food’ for your gut flora. It is fermented by bacteria, producing short chain fatty acids, which lower the pH level of your colon contents encouraging the growth of healthy bacteria in the gut.
  • Soluble Fiber slows the process of digestion through the stomach and the small intestine for a slower absorption of nutrients and is linked to lower cholesterol levels.
  • Insoluble Fiber helps normalize bowel function by increasing frequency and shortening transit time through the intestines.

Research indicates that all these fibers appear to work best in combination with each other—rather than acting in isolation.

There Are FOUR Types of Resistant Starches

  • RS1 is a starch that is physically inaccessible to digestion due to intact cell walls. This first type of resistant starch is found in whole grains.
  • RS2 is a native starch granule protected from digestion by the structure of the granule; raw potatoes and under ripe bananas are examples of RS2s.
  • RS3 is a cooked starch; rice or cooked potatoes are good examples.
  • RS4 is a chemically modified starch not found in nature and is tough to digest.

Why Do We Need Resistant Starch?

The traditional Western diet is high in animal protein (and fat), processed foods and refined carbohydrates and it is sorely lacking in dietary fiber.

By eating more resistant starches, you automatically increase your dietary fiber which delivers the following benefits:

  • Healthier Colon: When microbes digest starch, they produce butyrate. Butyrate maintains healthy colon lining and encourages mutated (potentially cancerous) cells to self-destruct.
  • Improved Metabolism: The production of butyrate may also improve blood sugar metabolism because resistant starch fermentation goes on for hours after food exits the small intestine.
  • Lowered Inflammation: Inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease are often treated (and reversed!) with a plant-based diet rich in dietary fiber. Dietary resistant starch encourages the growth of healthful gut microbiota.  Also, butyrate shows protective effects against intestinal mucosal inflammation.
  • The “I’m Full” Effect: Resistant starch might play a huge role in feeling satiated. In fact, recent studies indicate it enhances long term and short term feelings of “fullness”.
  • Balanced Gut: There’s a whole world of microbes in your gut and they change very rapidly in response to a change in your diet. A single day on a plant-based diet can boost the abundance of health-promoting starch-digesting microbes. (Conversely, just a single day of an animal-based diet shifts the gut microbiota the other way.)
  • Lowered Risk of Cancer: Increased dietary fiber is linked to preventing chronic illnesses like heart disease, type 2 diabetes, obesity and some cancers.

Where to Get Your Resistant Starches

The processed food industry got wind of the benefits for resistant starches; there’s a mad rush to add resistant starches to manufactured foods – ostensibly to improve our health. But the food industry is missing the point: the only reason you need to add something to a food is because you removed it in the first place!

And the whole food source is always the best source. No surprise here: whole, plant-based foods are rich in resistant starches. Here are the best whole food sources:

  • Legumes and beans
  • Green bananas and plantains
  • Yams and sweet potatoes
  • Potatoes and rice (cooked then cooled)
  • Other whole grains and tubers

Although the word “starch” combined with the word “resistant” may still give you nightmares, in reality this category of food can really have a positive impact on your health.

Now that doesn’t mean go crazy with eating white rice…The number 1 trick to healthy starches? Eat a wide variety of whole, plant foods. As always, the more variety you can add to your plate, the more you can help insure a healthy gut.

Rosane Oliveira, DVM, PhD

President & CEO, Plant-Based Life Foundation | Dr. Rosane Oliveira combines a lifelong passion for nutrition with 25 years of genetics research to create programs that help people develop healthy habits on their journey towards a more plant-based lifestyle. She is a Visiting Clinical Professor in Public Health Sciences and was the founding director of the first Integrative Medicine program at the UC Davis School of Medicine. She completed her postgraduate studies in Brazil and did her postdoctoral training in immunogenetics and functional genomics at the University of Illinois at Urbana-Champaign.