Growing clinical evidence suggests that resistant starch increases insulin sensitivity in the large and growing numbers of prediabetics, a segment of the population of interest to manufacturers of healthier foods. Prediabetes, in which blood glucose levels are higher than normal, is a strong predicator of diabetes and is associated with long-term damage to the body1. The Centers for Disease Control indicate that nearly 80 million adults and 50% of all Americans aged 65 years and older have prediabetes2.

Increasing insulin sensitivity and maintaining blood sugar levels within the normal range is a focus of prevention. Insulin resistance is a condition where the muscles and tissue lose sensitivity to insulin, the hormone required to effectively transport blood glucose. As people age and/or gain weight, their insulin resistance rises, eventually leading to increased blood glucose and the development of prediabetes.

Insulin Chart

Earlier this year, Maki et al.3 reported that high-amylose maize type 2 resistant starch (Hi-maize) increased insulin sensitivity in a group of overweight and obese men with elevated waist circumference. The study was a randomized, double-blind, controlled, crossover trial. Subjects consumed either 15 or 30g/d of resistant starch (measured as dietary fiber) from Hi-maize resistant starch or a control starch for four weeks. A statistically significant average improvement in insulin sensitivity of 56.5% and 72.7% for the low- and high-dose treatments, respectively, was noted. (See chart.) These results were independent of weight loss, currently recommended for preventing diabetes4.

This research supports five previous studies that showed positive effects on insulin sensitivity following Hi-maize resistant starch. These results were exhibited in healthy people5 and in people with type 2 diabetes6. This research provides evidence that modest levels of Hi-maize resistant starch can help individuals at risk for prediabetes maintain healthy blood sugar levels.

Hi-maize resistant starch is a natural ingredient isolated from a special hybrid of corn that is naturally high in amylose content. Resistant starch is not absorbed in the small intestine, because it is resistant to the effects of the alpha-amylose enzyme. Because it is not effectively broken down in the small intestine, resistant starch is considered to have similar physiological effects and health benefits as fiber.

During the last 20 years, more than 300 published studies—including more than 70 human clinical trials—have demonstrated a range of potential health benefits, including blood sugar and energy management, weight management and satiety. However, individuals in developed countries consume approximately 5g of resistant starch per day,7 whereas those in regions with fewer processed foods consume an average 15-20g per day8.

Hi-maize 260 resistant starch contains approximately 60% resistant starch (insoluble dietary fiber) and 40% digestible (glycemic) starch content. It can be added to foods such as breads, pizza and baked goods by partly replacing flour, or to smoothies and shakes. Hi-maize resistant starch improves the nutritional profile of processed foods, and does not impact taste, appearance or texture.  NS

For further information on Hi-maize, which is marketed by Ingredion Incorporated (formerly Corn Products International LLC), see For research updates, visit  




Maki, KC, Pelkman, CL, Finocchiaro, ET, et al. 2012. J. Nutr. 2012 Apr;142(4):717-23. doi: 10.3945/jn.111.152975.

Kahn, R. 2012. Health Affairs. 31(1):76-83.

Robertson, DM, Bickerton, AS, Dennis, AL, et al. 2005. Amer J Clin Nutr. 82:559-67.

Zhang, QW, Wang, HW, Zhang, YM. 2007. Chinese J Prev Med. 41:101-104.

Murphy, MM, Douglass, JS, Birkett, A. Journal of the American Dietetic Association, (2008), 108, 67-78.

Baghurst, PA, Baghurst, KI, Record, SJ. Food Australia (1996), 48(3)suppl:1-36.