Although resistant starch is technically a starch, it acts more like fiber during digestion than a starch. Typically, starches found in carbohydrate-rich foods such as grains, fruits, and vegetables, are broken down into glucose during digestion and that glucose is used as energy by the body. Much like fiber, resistant starch "resists" digestion and passes right through the small intestine without being digested. Because of this, some researchers classify resistant starch as a third type of fiber alongside soluble and insoluble fiber.
While resistant starch is found naturally in certain foods, the cooling period of the cooking process can create higher levels of resistant starch. When starchy foods are cooked, starch absorbs water and then swells. During cooling of cooked foods, some of the starch crystallizes into resistant starch. Cooling foods in the refrigerator or at room temperature will cause resistant starch levels to rise.
Health Benefits of Resistant Starch
Not only does resistant starch act like fiber during digestion, it also offers many of the same health benefits as fiber, including:
- Aids weight loss and digestive health
- Helps prevent constipation
- Helps to maintain blood sugar levels
- Reduces the risk of developing diabetes and heart disease
- Boosts immunity
- Reduces the risk of colon cancer
- Increases mineral absorption
Foods High in Resistant Starch
There are many foods that contain resistant starch, including:
Beans: 1/2 cup cooked navy beans has 3.8 grams of resistant starch, while 1/2 cup cooked black beans has 2 grams.
Slightly green bananas: 1 medium green banana contains 4.7 grams of resistant starch.
Potatoes: 1 medium potato that is boiled and then cooled has 1.3 grams.
Barley: 1/2 cup cooked pearl barley contains 1.9 grams of resistant starch.
Brown rice: 1/2 cup cooked brown rice has 1.7 grams of resistant starch.
Corn: 1/2 cup cooked corn contains 0.3 grams.
Split peas: 1/2 cup cooked has 3.1 grams of resistant starch.
Other sources of resistant starch are lentils, whole-wheat pasta, white rice, oatmeal, and whole-grain bread.
As of yet, there are no official recommendations as far as how much resistant starch to eat daily. Some experts suggest eating 5 to 30 grams of resistant starch per day to enjoy the health benefits it provides.
Further Reading
To find out how carbohydrates affect the body, see Types of Carbs and Nutrition. For general information on making healthy food choices, see Eating a Healthy Diet.
References:
Stokes, Milton D. (March 2008). "Nature's Fat-Burning Breakthrough: Why Eating Carbs Can Help You Slim Down--And How to Do it Right." Prevention.com
Bourassa, Barbara C. (November 2008). "Weight-Loss Miracle?" Body+Soul.
