Not all starch is the same!
You’ve heard about the health benefits that are available from consuming higher amounts of fiber in your diet. Now there’s a better way to reach these goals and gain a wide variety of additional important help benefits – natural resistant starch.
Without changing their diets, without sacrificing taste and convenience, consumers can obtain valuable health advantages and additional fiber by eating popular foods like breads, pasta and cereal containing this natural resistant starch from corn.
This page explains what resistant starch is, its many health benefits and its unique advantages over other fiber sources.
What is resistant starch?
Is resistant starch new?
Are all resistant starches the same?
What’s the difference between fiber & resistant starch?
Is resistant starch in foods we already eat?
How is resistant starch made?
What are the benefits of HI-MAIZE® resistant starch?
How much should we consume daily?
Is there any upper limit for consumption?
How many calories does it have?
How is HI-MAIZE resistant starch labeled?
What foods can feature this?
What are the advantages?
Resistant starch is a type of starch that “resists” digestion in the small intestine and reaches the large intestine. Naturally occurring resistant starch generally contains a portion of starch that is slowly digestible and a portion that truly “resists” digestion.
In general, carbohydrates can be classified into three groups: those that are quickly digested in the small intestine, those that are slowly digested in the small intestine and those that reach the large intestine.
- Sugars and most starches fall into the first group. They are quickly digested and absorbed, and subsequently used for short-term energy needs or stored. These are referred to as available, digestible or glycemic carbohydrates.
- Some of the starch in naturally occurring resistant starches are slowly digested and absorbed in the small intestine. This category is emerging as researchers have been researching the glycemic impact of various types of carbohydrates.
- Resistant starch and dietary fiber constitute the third group. By definition, they pass through the small intestine and provide no short-term energy but have a variety of physiological effects in (and emanating from) the large intestine. Natural resistant starches are fermented like some dietary fibers and provide long-term energy. These are referred to as non-glycemic carbohydrates.
Not at all. Resistant starches have always been with us. But it is only recently that we have begun to understand them. Historically, scientists thought that all starches were fully digested. Today, researchers have discovered that some starches move undigested into the large intestine where, through fermentation, they take on many of the roles – and provide the benefits of – other carbohydrates long recognized as dietary fiber.
For the past two decades, there has been a steady increase in our knowledge of the sources, uses and physiological effects of resistant starch. However, it has only been in the past decade that the use of ingredients with high resistant starch content has occurred in foods throughout the world. This has allowed consumers everywhere to take advantage of the important health advantages of this ingredient.
No they’re not! Today’s resistant starches are typically categorized into four classes:
||Resistant starch that occurs in its natural granular form, such as uncooked potato, green banana flour and high amylose corn (i.e. HI-MAIZE® resistant starch).|
||Resistant starch that is formed when starch-containing foods are cooked and cooled such as in bread, cornflakes and cooked-and-chilled potatoes or retrograded high amylose corn.|
||Selected chemically modified and acid-modified resistant starches, not found in nature.|
What’s the difference between fiber and resistant starch?
It’s long been thought that there were only two kinds of fiber – soluble and insoluble. Over the last 20 years nutrition research has demonstrated that there is a third kind – resistant starch. All three kinds of fiber are essential to health.
Insoluble Fiber (e.g., cellulose, lignan and hemicellulose): found in whole grain bread, wholegrain cereals, fruits, vegetables, unprocessed bran and wheat germ. Insoluble fiber absorbs water to provide bulking and help keep us “regular.”
Resistant Starch: starches that escape digestion in the small intestine and reach the large intestine. Natural resistant starch (RS1 and RS2) is insoluble, is fermented in the large intestine and is a prebiotic fiber, providing some of the health benefits of both soluble (prebiotic, fermentable fiber) and insoluble fiber (bulking and regularity) – plus some unique advantages of its own (insulin sensitivity and long term satiety). The characteristics of other types of resistant starches vary and the benefits are largely unknown.
Resistant starch is naturally present in foods such as unprocessed whole grains, under-ripe bananas, legumes and lentils. Small amounts of resistant starch are also created in cooked-and-cooled pasta, cold rice (e.g., sushi) and potato salad. As researchers learn more and more about its health benefits and ease of use, resistant starch is quickly gaining attention as an ideal way to add fiber to a wide range of foods. Many public health authorities and food organizations such as the Food and Agricultural Organization, the World Health Organization1, the British Nutrition Foundation2 and the U.S. National Academy of Sciences3 now recognize resistant starch as a beneficial starch and a type of dietary fiber.
Currently, there is only one commercially available natural resistant starch on the market – HI-MAIZE® resistant starch. This natural ingredient made from corn can be added to breads, cereals, pasta, nutrition bars and more.
HI-MAIZE 260 resistant starch is isolated from high amylose corn hybrids produced through traditional plant breeding. Other naturally occurring sources do not have the process tolerance offered by high amylose corn. A mild heat/moisture treatment helps to align the amylose chains within the natural starch granule. Because it retains its natural granule structure, it is a Type 2 Resistant Starch (RS2).
There is substantial research on the health benefits of HI-MAIZE 260 resistant starch, including more than 350 published, peer-reviewed studies that indicate benefits in intestinal/colonic health as well as metabolically important benefits in glycemic management and weight management.
Of the nutritional studies mentioned above, more than 70 studies in humans show that HI-MAIZE resistant starch contributes specific health benefits. Just a few examples:
- A 2011 clinical trial by Dr. Kevin Maki and his colleagues at Provident Clinical Research in the United States showed that a diet containing a low dose of HI-MAIZE 260 resistant starch significantly improved insulin sensitivity and helped maintain healthy blood sugar levels in overweight men at risk for prediabetes. The study found that men had 73 % increased insulin sensitivity with a 30 g of fiber from HI-MAIZE resistant starch/day and a 57% increased insulin sensitivity with a 15 g of fiber from HI-MAIZE resistant starch/day. 4
- A 2010 clinical trial by Dr. Harvey Anderson and his colleagues at the University of Toronto in Canada demonstrated that glycemic response and subsequent food consumption correlated directly with the quantity of resistant starch in the diet. Individuals consuming foods containing HI-MAIZE 260 resistant starch consumed significantly less food two hours later compared to the foods containing high glycemic maltodextrin. 5
- Clinical trials published by Dr. Denise Robertson and her colleagues at the University of Surrey in England show that HI-MAIZE 260 resistant starch increases insulin sensitivity in healthy people and in individuals with higher blood glucose levels than normal but not yet high enough to be diagnosed as diabetes. 6,7
- Numerous studies demonstrate that HI-MAIZE resistant starch promotes intestinal/colonic health through its fermentation within the large intestine.8 It encourages the growth of health-promoting bacteria, reduces pH and increases the production of butyrate via fermentation. Butyrate, a short-chain fatty acid, is important for colonic health and has been shown to have many health-promoting properties. The latest studies from Dr. David Topping and his colleagues from the CSIRO in Australia have shown that resistant starch helps to protect the intestinal tract from the harmful effects of high protein diets.9
This substantial amount of data provides a high level of confidence in the benefits that could be obtained through the consumption of HI-MAIZE resistant starch. For more information on research on HI-MAIZE resistant starch, see the Clinical Studies section of this website.
Public health authorities and governments have not yet set recommended levels for resistant starch consumption. The Joint Food and Agricultural Organization of the United Nations/World Health Organization Expert Consultation on Human Nutrition stated, “Perhaps the greatest impact of recent knowledge is our growing understanding of the diverse physiological roles that carbohydrates have, depending to a great extent on the site, rate, and extent of their digestion and fermentation in the gut…One of the major developments in our understanding of the importance of carbohydrates for health in the past twenty years has been the discovery of resistant starch.” 10
In Australia, where resistant starch has been most extensively studied, the Division of Human Nutrition at CSIRO (Commonwealth Scientific and Industrial Research Organization – Australia’s national scientific research organization) advises that "... intakes in the order of 20 grams per day of resistant starch may be needed to obtain some of the bowel related benefits.” 11
Resistant starch intakes vary greatly around the world. Currently most developed countries consume between 3-7 grams of resistant starch per day.
The entire daily-recommended intake of dietary fiber (>25 grams according to the World Health Organization) could be consumed from HI-MAIZE resistant starch without digestive side effects. One review of eight published human clinical studies concluded that individuals could consume up to 45 grams of dietary fiber from high amylose corn resistant starch without side effects.12
For labeling purposes in the United States, HI-MAIZE 260 resistant starch contains 1.4 kilocalories/gram.
HI-MAIZE resistant starch is usually designated simply as “resistant corn starch” or “corn starch” on food product labels. It analyzes as insoluble dietary fiber and is listed as fiber on the nutritional information on product labels.
Resistant starches have been used successfully in breads, cakes, pasta, cereals, snacks and other baked goods. They can also be added to some beverages (i.e., smoothies), oatmeal and other mixed entrees.
Resistant starch offers three main advantages over other fiber-fortification options like bran, cellulose and inulin.
HI-MAIZE resistant starch offers unique health benefits, including metabolically important benefits in glycemic management and weight management. Other non-fermentable or less fermentable fibers such as wheat bran and cellulose cannot match HI-MAIZE resistant starch’s benefits because many of the benefits stem from HI-MAIZE resistant starch’s fermentation in the large intestine.
Resistant starch is “invisible” in foods – it doesn’t affect taste and texture like other insoluble fiber sources often do. Resistant starch has unique functional properties yielding high quality foods, and is especially appropriate for grain-based low- and moderate-moisture foods because it commonly replaces flour. Its physical properties, particularly its low-water-holding capacity, enable it to be used to provide good food processing characteristics and desirable textural attributes such as crispness and expansion when compared to foods of similar fiber content.
||Unlike the rapid fermentation that occurs with some soluble fibers like inulin, HI-MAIZE resistant starch is slowly fermented and can be consumed at very high quantities without digestive side effects. |
1. Carbohydrates in Human Nutrition
, Joint FAO/WHO Expert Consultation in Human Nutrition, April 1997
2. Nugent, A.P., Health properties of resistant starch
, 2005, British Nutrition Foundation Nutrition Bulletin, Vol. 30, No. 1:27-54.
3. “Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fatty Acids, Cholesterol, Protein and Amino Acids (Macronutrients)” The Institute of Medicine of the National Academies, September 5, 2002.
4. Maki KC, Pelkman CL, Kelley KM, Lawless AL, Schild A, Rains TM. Effects of Type 2 resistant starch consumption on insulin sensitivity in men and women. #587.9 Presented at Experimental Biology, April 10, 2011.
5. Anderson GH, Cho CE, Akhavan T, Mollard RC, Luhovyy BL, Finocchiaro ET. Relation between estimates of cornstarch digestibility by the Englyst in vitro method and glycemic response, subjective appetite, and short-term food intake in young men. American Journal of Clinical Nutrition
6. Robertson, M.D., Bickerton, A.S., Dennis, A.L., Vidal, H., Frayn, K.N. Insulin-sensitizing effects of dietary resistant starch and effects on skeletal muscle and adipose tissue metabolism. American Journal of Clinical Nutrition
, (2005), 82, 559-567.
7. Johnston KL, Thomas EL, Bell JD, Frost GS, Robertson MD. Resistant starch improves insulin sensitivity in metabolic syndrome. Diabetic Medicine (2010) 27, 391–397; doi: 10.1111/j.1464-5491.2009.02923.
x.10. de Haen, H. (FAO Assistant Director-General, Economic & Social Dept), Carbohydrates in Human Nutrition
, FAO Food & Nutrition Paper – 66
. A Joint FAO/WHO Expert Consultation on Human Nutrition, Rome, April 14-18, 1997.
8. Topping, DL, Bajka, BH, Bird, AR, Clarke, JM, Cobiac, L, Conlon, MA, Morell, MK, Toden, S. Resistant starches as a vehicle for delivering health benefits to the human large bowel. Microbial Ecology in Health and Disease 2008; 20(2) 103-108.
9. Toden S, Belobrajdic DP, Bird AR, Topping DL, Conlon MA. Effects of dietary beef and chicken with and without high amylose maize starch on blood malondialdehyde, interleukins, IGF-1, insulin, leptin, MMP-2 and TIMP-2 concentrations in rats. Nutrition and Cancer May 2010; 62(4):454-465.
10. Carbohydrates in Human Nutrition, Joint FAO/WHO Expert Consultation in Human Nutrition, April 1997.
11. Baghurst PA, Baghurst KI, Record SJ, Dietary fibre, non-starch polysaccharides and resistant starch – a review
. Food Australia, 1996 Vol 48, No. 3:S1-S35.
12. Grabitske HA, Slavin JL. Gastrointestinal effects of low-digestible carbohydrates. Critical Reviews in Food Science and Nutrition
. (2009) 49:327-360.