Resistant starch

What is it?

Resistant starch is a form of starch that is not fully broken down and absorbed in the small intestine. In other words, it is resistant to digestion. It passes through the small intestine intact and is then fermented in the large intestine. As a result, it is classified as a type of dietary fiber.

Resistant starch acts more like a prebiotic than a typical starch. A prebiotic is what good bacteria (probiotics) eat. So once the resistant starch arrives in the colon, the good bacteria feeds on the starch, producing something called butyrate (butyric acid), a short-chain fatty acid.

These starches are “invisible”, meaning it doesn’t alter the appearance, taste or texture of foods.

Where and Why is it used?

Resistant starch is found in starchy plant foods such as beans/legumes, starchy fruits and vegetables (such as bananas), whole grains and some types of cooked then cooled foods (such as potatoes and rice). Longer cooking times or cooking at higher temperatures will lower the amount of resistant starch. The amount of resistant starch in food can change. For example, allowing a banana to ripen will degrade the resistant starches and turn them into regular starches.

Resistant starch is tolerated best when it is in solid food form rather than liquid, when it is consumed as part of a mixed meal rather than alone, and when its consumption is increased gradually over time rather than a lot at once.

Experts from the European Food Safety Authority (EFSA) recommend a daily intake of 25 grams of dietary fiber for normal bowel function in adults. In addition, scientific evidence shows that there are health benefits associated with higher intakes of dietary fiber in adults, such as improved insulin sensitivity, improved immunity, lower blood sugar levels, reduced appetite and various benefits for digestion.

One of the main reasons why resistant starch improves health, is that it feeds the friendly bacteria in the intestine and increases the production of short-chain fatty acids like butyrate.