The blood sugar benefits of type 2 resistant (rs2) RHONDA S. WITWER Ingredion Incorporated, 10 Finderne Avenue, Bridgewater, New Jersey 08807, USA

Rhonda S. Witwer

KEYWORDS: blood sugar; metabolism; ; resistant starch; ; sensory.

ABSTRACT: Consumers are concerned about the impact of on their blood sugar levels. While there has been considerable discussion on the post-prandial glycemic response of , the research has been chronically inconsistent in confirming potential health benefits. In contrast, insulin sensitivity is directly connected to maintaining healthy blood sugar levels. This review will profile the evidence demonstrating that type 2 resistant starch from high corn is ideal for formulating foods to help people manage their blood sugar levels. It has a reduced post-prandial glycemic response, it significantly improves insulin sensitivity and blood sugar metabolism, it replaces in formulations while maintaining the taste and textures that consumers prefer and it can be used as a supplement to the diet.

The market for foods that help manage blood sugar levels is signals the tissues that is available as energy and emerging. The low diet fad of ten years ago helps to prevent fat from being burned and released out of was a major shock to the industry that carbohydrates storage. In individuals with healthy metabolism, this works and their impact on weight and blood sugar levels were very well. The muscles and tissues are sensitive to the insulin important to consumers. While the food industry focused and respond by transporting glucose quickly. However, on whole grains in the intervening decade, consumers these metabolic systems can lose their fl exibility and cease

Food technologies ingredients to improve consumer's perception did not forget about the importance of their blood sugar to work well, a process that can develop over many years. levels and many continued to avoid carbohydrate-rich foods. Recently, 26% of American primary grocery shoppers The muscles and tissue within the body may begin to reported that they had decreased their consumption of resist the effects of insulin, which is called loss of “insulin carbohydrates within the past two years, according to the sensitivity”. This is accelerated in individuals that are 2013 HealthFocus Trend Survey. In addition, Euromonitor genetically predisposed or who are overweight and reports that retail volume of baked goods are expected to commonly occurs with aging. For insulin resistant individuals decline by 3% in the US market between 2011 and 2016 (1). to maintain control over blood glucose levels, their pancreas releases higher levels of insulin. First, post-prandial While the larger, mainstream markets are struggling to insulin responses spike higher and higher but fasting and grow, innovative companies are venturing into new post-meal glucose levels remain normal. Over time, as vol 24(3) - May/June 2013

- business development in foods that help manage blood insulin resistance increases, fasting insulin levels also start

sugar levels. For instance, “Made for You Foods”, in to rise. Eventually, the pancreas is damaged by the high Australia, sells frozen meals that are levels of glucose or simply cannot produce more insulin designed “for people watching their and it starts to fail, resulting in less insulin production. At blood sugar”. Their message is this point, the body starts to lose control of its glucose and reinforced by a “D-tick” logo, blood glucose levels start to rise. All of these changes in which Made For You Foods metabolism are generally invisible, as doctors routinely created to signify that it meets monitor only blood glucose levels and not insulin levels. It the Australian Diabetes Council’s has been estimated that by the time an individual has been nutrient criteria. It focuses on diagnosed with type 2 diabetes, they have lost 50-80% of Agro FOOD Industry Hi Tech delivering portion-controlled foods their insulin-production capabilities (beta-cell function) (2). with a reduced post-prandial glucose response. According to the International Diabetes Federation, more than 371 million adults are already living with diabetes, which represents more than 8% of the global population BACKGROUND (3). This number is projected to increase to 552 million people by 2030, or 9.9% of adults, which equates to After people eat food, the carbohydrates in that food approximately three more people with diabetes every 10 are digested and broken down to the glucose, which are seconds. Diabetes caused at least USD 471 billion dollars in absorbed and cause an increase in glucose (sugar) in the healthcare expenditures in 2012; 11% of total healthcare bloodstream (called post-prandial glucose response). If expenditures in adults (20-79 years). The expense is the carbohydrates are slowly digested or resist , staggering and is rapidly climbing. the rise is slow and gradual. If, however, the carbohydrates are easily digested, the rise is steep and fast. In response to Within the United States, the Centers for Disease Control the glucose surge, the pancreas releases insulin to assist in report than 33% of American adults have prediabetes (4), moving glucose from the blood stream into muscles, tissues which is defi ned as fasting blood glucose levels between and the brain, where it is utilized as energy. Insulin also 100 mg/dl and 126 mg/dl. In short, blood glucose levels are

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Food technologies ingredients to improve consumer's perception Agro FOOD Industry Hi Tech - vol 24(3) - May/June 2013 35 (CSIC) glycemic response when standardized to the quantity quantity to the standardized when response glycemic In 2011, The carbohydrates. “glycemic” or of “available” a claim (EFSA) approved Food Safety Authority European post-prandial glycemic starch reduced the that resistant of the a minimum of 14% it substituted for response when starch (17). digestible corn starch also type 2 resistant More importantly, blood sugar metabolism. long-term cantly impacts signifi cantly improves shown that it signifi Six clinical studies have Lower insulin levels are found after insulin sensitivity (18-23). ts have been found Similar benefi only 30 minutes ((24). individuals with insulin resistance, in healthy individuals, and individuals with type 2 diabetes. overweight individuals that three tablespoons of Type 2 A 2012 study found added as a supplement to the diet resistant corn starch in overweight men by 56% (21). increased insulin sensitivity to be similar in women (even though t is believed The benefi did not show it) as prior studies also this particular study sensitivity in women. found improved insulin study demonstrated that dietary One recent clinical also shifted fat consumption of RS2 resistant corn starch been reported that storage within adipose tissue (19). It has obesity have low individuals with type 2 diabetes and/or (26, 26). These levels of key lipases in their adipose tissue fat. If storage lipases are responsible for properly storing tissue, the fat mechanisms are not working well in lipase stored in circulating in the blood is eventually improperly where it directly the muscle, the pancreas and the liver, the lipases causes increases in insulin resistance. Increasing vicious cycle linking in adipose tissue may help to break the Robertson fed fat with rising insulin resistance. Dr. Denise RS2 resistant obese men and women with insulin resistance for key corn starch and demonstrated clear stimulation are responsible lipases within the adipose tissue, which to for fat storage. This shift in fat storage contributes maintaining healthy blood sugar metabolism. onset of insulin Animal studies have also shown delayed found improved resistance (27). One recent animal study within functioning and preservation of the beta-cells well as inter- the pancreas (which produce insulin) as ts (28). generational blood sugar benefi RS2 RESISTANT CORN STARCH FUNCTIONAL CHARACTERISTICS starch with ne corn RS2 resistant corn starch is a white, fi It can avor and low water-holding capacity. a bland fl in both our in food formulations replace 10-20% of the fl industrial manufacturing as well as home use or utilized by consumers as a supplement to the diet. Numerous studies have found that it can be utilized with minimal impact on taste, texture and sensory properties. For instance, Dr. Susana Fiszman and her colleagues at Instituto de Agroquímica y Tecnología de Alimentos in Valencia, Spain, studied the textural impact of increasing ns (29). They found levels of RS2 resistant corn starch in muffi number and area of n height or the little impact on the muffi gas cells in the crumb, up to 10% of RS2 resistant corn starch n. A separate study by the same team found in the muffi that consumers rating for moisture content and sweetness rose with increasing levels of RS2 resistant corn starch, even ns tested though the sugar content was the same for all muffi (30). An increased grittiness was detected, especially at 20% of the formulation, but these characteristics did not affect the “overall liking” score in a sensory consumer panel. Dr. Fiszman and her colleagues have also studied RS2 resistant corn starch in biscuits. Short-dough biscuits were formulated with a reduced fat content using a mixture Type 2 resistant corn starch from high amylose corn (15), an Type 2 resistant corn starch from high amylose corn (15), an for use in foods bre, is an ideal ingredient insoluble dietary fi for managing healthy blood sugar levels. When it substitutes have shown that our, twenty out of twenty one studies for fl the post-prandial glycemic response is reduced (16). In contrast, it does not lower the Glycemic Index, as only 4 out of 9 studies found a reduced Glycemic Index or reduced TYPE 2 RESISTANT CORN STARCH SCIENTIFIC EVIDENCE OF TYPE 2 RESISTANT CORN STARCH SCIENTIFIC EVIDENCE OF BENEFITS There is general consensus about glycemic and weight and weight There is general consensus about glycemic ts of eating foods with a lower post-prandial benefi (8, 9). However, glycemic response, especially for diabetics ts in healthy populations are less certain: some the benefi ts (10-12), while other reviews have demonstrated benefi ts in some populations but not reviews have shown benefi One of the others (13) or have been inconclusive (14). to isolate the cult major issues is that it has been very diffi impact of lower post-prandial glycemic response of foods without also at the same time increasing the quantity of ts are actually non-digestible carbohydrates. If the benefi due to the non-digestible carbohydrates instead of the (high fat, cial approaches glycemic reduction, non-benefi high fructose, etc.) could be utilized to design foods for reduced glycemic response. However, these approaches as incorporating cial effect would not have the same benefi bre and non-digestible carbohydrates such as dietary fi resistant starch into those foods. The ILSI review of 2011 concluded that clearer insights are needed before authorities could potentially endorse the communication of Glycemic associated claims to consumers (10). REDUCING THE POST-PRANDIAL GLYCEMIC RESPONSE REDUCING THE POST-PRANDIAL GLYCEMIC Consumers around the world are already concerned about world are already concerned about Consumers around the to recent the health impact of carbohydrates. According Spanish grocery HealthFocus International trend surveys, as 42% of Spanish shoppers may be the most concerned, is an extremely shoppers report that “low carbohydrate” or usually or very important label claim and 27% always diet. The US is not follow a low carbohydrate/high protein reporting that far behind, with 33% of grocery shoppers important “low carbohydrate” is an extremely or very shoppers always or label claim and 23% of primary grocery blood sugar levels. usually choosing foods to manage their their In addition, 32% of American shoppers decreased years. consumption of sugar within the past two CONSUMERS ARE CONCERNED ABOUT MANAGING THEIR ABOUT MANAGING THEIR CONSUMERS ARE CONCERNED BLOOD SUGAR Maintaining healthy blood sugar levels are important not not levels are important healthy blood sugar Maintaining for to be important 2 diabetes, it appears only for type resistance is an underlying as well. Insulin other diseases Syndrome (6), which doubles the risk factor in Metabolic disease. In addition, risk of developing cardiovascular Alzheimer’s Disease as a researchers are investigating of diabetes as insulin sensitivity possible type 3 category in the progression of both types of is critically important diseases (7). higher than normal (£ 100 mg/dl) but not yet high enough high enough not yet mg/dl) but (£ 100 than normal higher mg/dl). (≥126 as type 2 diabetes ed classifi to be that they have less than 10% know Unfortunately, (5). prediabetes of tapioca dextrin and starch to replace the fat. The 10. Sadler M. ILSI Europe Concise Monograph Series, Food trained panellists found that the fat replacer increased Glycaemic Response and Health. November 2011:1-30. the hardness and crumbliness of the biscuits, but that Available online at www.ilsi.eu. these effects were balanced out by 20% RS2 within the 11. Fan J, Song Y, Wang Y, Hui R, Zhang W., PLOS One Dec 2012; 7(12):e521. formulation (31). Thus, RS2 resistant corn starch contributes 12. Livesey G, Taylor R, Livesey H, Liu S., Am J Clin Nutr; 97(3), 584- to enhanced softer texture and enhanced performance in 596 (2013) a reduced fat biscuit. 13. Mirrahimi A, de Souza RJ, et al., JAHA.,1:e000752 (2012). Dr. Mike Sissons and his colleagues at the Tamworth 14. Blaak EE, Antoine J-M, et al., Obesity Reviews, 13(10), 923-984 Agricultural Institute in New South Wales, Australia, studied (2012). the use of RS2 resistant corn starch in pasta formulations 15. Hi-maize™â RS2 resistant starch from high amylose corn, (32). They found that 10% and 20% RS2 substitution of manufactured by Ingredion Incorporated, was utilized in the semolina had no signifi cant effects on pasta cooking clinical trials and sensory and formulation studies cited in this loss, texture and sensory properties, with only a minimal review. reduction in pasta yellowness. 16. Witwer RS. Natural resistant starch in glycemic management: from physiological mechanisms to consumer communications. Finally, food formulations containing RS2 resistant corn In “Nutraceuticals, Glycemic Health & Type II Diabetes” Edited starch are consumer-friendly due to its high tolerance. As by Vijai K. Pasupuleti and James W. Anderson. IFT Press, Wiley- an insoluble starch granule, it is fermented slowly through Blackwell Publishers, (August, 2008) pp 401-438. the . Unlike many fermentable soluble 17. European Food Safety Authority, Scientifi c Opinion on the fi bres, the resident bacteria simply cannot access all of substantiation of health claims related to resistant starch and the content due to the physical granular structure of RS2 reduction of post-prandial glycaemic responses (ID 681), starch. One study found that consumers would need to “digestive health benefi ts” (ID 682) and “favours a normal consume 75 grams of RS2 resistant corn starch (containing colon metabolism” (ID 783) pursuant to Article 13(1): of 45 grams of dietary fi bre) before signifi cantly increasing Regulation (EC) No. 1924/2006. EFSA Journal 2011;9(4):2024. gas (33). Even at these high levels, the participants did not 18. Robertson MD, Currie JM, et al., Diabetologia, 46(5), 659-65 (2003). experience bloating or abdominal pain. 19. Robertson MD, Bickerton AS, et al., Am J Clin Nutr, 82(3), 559-67 (2005). 20. Zhang W, Wang H, Zhang Y, Yang Y., Chinese Journal of SUMMARY Preventive Medicine, 41, 101-4 (2007). 21. Johnston KL, Thomas EL, Bell JD, Frost GS, Robertson MD., Diabet In conclusion, consumers want foods that can help them Med, 27(4), 391–7 (2010). manage their blood sugar levels, which presents a growth 22. Robertson MD, Wright JW, et al., J Clin Endocrinol Metab, 97(9), 3326-32 (2012). Food technologies ingredients to improve consumer's perception opportunity for the food industry. Many processed, carbohydrate-rich foods can cause high spikes and 23. Maki KC, Pelkman CL, et al., J Nutr, 142(4), 717–23 (2012). rapid decreases in post-prandial blood sugar, which may 24. Bodinham CL, Frost GS, Robertson MD.et al., Br J Nutr, 103(6), 917-22 (2010) contribute to degradations in blood sugar health. It is 25. Watt MJ, Carey AL, et al., Diabetologia; 48, 105–112 (2005). possible to formulate better-for-you versions of these foods 26. Berndt J, Kralisch S, et al., Exp Clin Endocrinol Diabetes 116, utilizing RS2 resistant corn starch to replace some of the 203–210 (2008). fl our to not only lower the post-prandial glucose response 27. Higgins JA, Brand Miller, JC, Denyer GS., J Nutr; 126, 596-602 but also to signifi cantly improve insulin sensitivity and blood (1996). sugar metabolism. The resulting foods maintain similar taste 28. Shen L, Keenan MJ, Raggio A, Williams C, Martin RJ. Mol Nutr and texture to non-fortifi ed versions and have higher levels Food Res, 55(10), 1499-1508 (2011). of dietary fi bre. 29. Baixauli R, Sanz T, Salvador A, Fiszman SM., J Cereal Sci, 47, 502-

vol 24(3) - May/June 2013 509 (2008). - 30. Baixauli R, Salvador A, Martínez-Cervera S, and Fiszman SM., LWT - Food Science and Technology, 41(10), 1927-1933 (2008) REFERENCE AND NOTES 31. Laguna L, Varela P, Salvador A, Sanz T, Fiszman SM., J Texture Stud, 43(3), 235-45 (2012) 1. Euromonitor International, Passport Report: Baked Goods in the 32. Aravind N, Sissons M, Fellows CM, Blazek J, Gilbert EP., Food US, September 2011. Chem., 136(2), 1100-1109 (2013). 2. DeFronzo RA. Diabetes, 58, 773-795 (2009). 33. Jenkins DJA, Kendall CWC, Emam A, Wong J, de Souza R, 3. International Diabetes Federation, IDF Diabetes Atlas, 5th Marchie A, Birkett A, Jeffcoat R. Assessment of Resistant Starch edition, http://www.idf.org/diabetesatlas/5e/Update2012, Tolerance: a dose-response study. Unpublished information to accessed March 12, 2013. Ingredion Incorporated.

Agro FOOD Industry Hi Tech 4. Centers for Disease Control and Prevention. Diabetes Report Card 2012. Atlanta, GA: Centers for Disease Control and Prevention, US Department of Health and Human Services; 2012. 5. Geiss LS, James C, et al., Am J Prev Med., 38(4),403-409 (2010). 6. Grundy SM, Cleeman JI, et al., Circulation; 112, 2735-2752 (2005). 7. De la Monte SM, Wands JR., J Diabetes Sci Technol Nov, 2(6), 1101-1113 (2008). 8. Guideline for Management of Postmeal Glucose, International Diabetes Federation, 2007. Available online at www.idf.org. 9. Ajala O, English P, Pinkney J., Am J Clin Nutr; 97(3), 505-516 (2013).

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