Resistant starch is not broken down in the small intestine and passes into the large intestine, where it is partially or completely fermented. Resistant starch acts as dietary fiber, according to the September 2006 issue of “Obesity.” Its consumption is associated with a number of health benefits including better insulin sensitivity, as reported in the April 2010 issue of “Diabetic Medicine.” The "Manual of Dietetic Practice" lists four types of resistant starch.
Physically Inaccessible Starch
According to the "Manual of Dietetic Practice," physically inaccessible resistant starch is starch that digestive enzymes cannot get to, because it is enclosed in an impenetrable structure such as a seed husk. The top foods rich in this kind of resistant starch include seeds such as flax and pumpkin, corn on the cob and whole grains.
Granular Starch
Starch occurring in a particular granular form is resistant to digestion because its structure makes it hard for the digestive enzymes to act on, reports the “Manual of Dietetic Practice.” The best food sources of this type of starch are raw potatoes and green bananas. However, if you are not used to eating these kinds of foods, their consumption can cause bloating and diarrhea. Only consume very small quantities at first -- for example, a spoonful of unripe bananas.
Retrograded Starch
This type of resistant starch occurs when starch-containing foods are cooked and then cooled, as explained in the “Manual of Dietetic Practice.” The starch assumes a structure that is difficult for your body to digest. The difference from granular starch is that granular starch has an indigestible structure by nature, while retrograded starch only assumes an indigestible structure when cooked and then cooled. The main source of retrograded starch is cooked and cooled potatoes. The November 2007 issue of the “European Journal of Clinical Nutrition” reports that most people tolerate up to 60 g of retrograded resistant starch. However, a mild laxative effect can occur if you consume more than 60 g in one meal.
Chemically Modified Starch
Chemically modified starch is starch modified synthetically to make it resistant to digestion, as reported in the “Manual of Dietetic Practice.” Modified starches are used in reduced-fat products such as reduced-fat sausages and as an emulsifier in some salad dressings involving water and oil mixtures. Instant desserts also tend to be a source of modified starch, but note that these products are usually high in calories. Examples of instant desserts containing modified starch are cheesecake and pudding.
Recommended Intake
The American Dietetic Association recommends that you consume 20 to 35 g of fiber daily. Resistant starch intake counts toward your fiber intake, so including whole foods rich in this type of starch can be a good way to bump up your intake of this nutrient.
References
- “Obesity”; Effects of Resistant Starch, Non-Digestible Fermentable Fiber, on Reducing Body Fat; M.J. Keenan, et al.; September 2006
- “Diabetic Medicine”; Resistant Starch Improves Insulin Sensitivity in Metabolic Syndrome; K.L Johnston, et al.; April 2010
- "Manual of Dietetic Practice, 4th Edition"; T. Briony and J. Bishop; 2007
- “European Journal of Clinical Nutrition”; Gastrointestinal Responses Following Acute and Medium Term Intake of Retrograded Resistant Maltodextrins, Classified as Type 3 Resistant Starch; D. Storey, et al.; November 2007
- "Journal of the American Dietetic Association"; Position of the American Dietetic Association: Health Implications of Dietary Fiber; July 2002
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