A study presented at the Annual Obesity Week conference on Nov. 4 shows that high amylose resistant starch (HI-MAIZE) may improve insulin sensitivity in women.
Resistant starch is a type of dietary fiber that has beneficial metabolic effects including lowering blood glucose concentrations and improving insulin sensitivity. The study was performed to better understand its effects in women.The study was conducted in 43 healthy normal-weight and obese, pre- and post-menopausal women ages 22–68, using a randomized, placebo-controlled, double-blind crossover design. HI-MAIZE 260 corn starch was formulated into snack foods and tested at two doses, 15 g and 30 g resistant starch per day. An isocaloric snack formulated with a highly-digestible waxy corn starch served as a control. The participants consumed the snack foods for four-week intervals with a four-week washout period between the three test periods. Insulin sensitivity was assessed at the end of each test period using an intravenous glucose tolerance test.
The results show that the high amylose resistant starch improved insulin sensitivity in the combined group of pre- and post-menopausal women. Baseline insulin sensitivity and waist circumference affected the response. A subset of women with unusually high insulin sensitivity was identified, and no improvement was found in this subgroup. For the remainder of the women, a 26% improvement in insulin sensitivity was found after consuming the snacks containing 30 g resistant starch compared to the snacks containing no resistant starch. The effects were also affected by waist circumference with greater improvements noted in women with larger waists.