New potential health benefits of resistant starch revealed

GLOBALLY, obesity and diabetes are approaching epidemic proportions. There are currently 382 million people suffering from diabetes worldwide^[1], with more than half residing in Southeast Asia and the Western Pacific. In 2013, China and India had the highest numbers of people suffering from diabetes worldwide, with 98.4 million and 65.1 million respectively. Indonesia (8.5 million), Japan (7.2 million) and Bangladesh (5.1 million) had the highest number of people with diabetes in the Southeast Asian and Western Pacific regions ^[2].

About 90-95% of these people have what is classified as Type 2 diabetes ^[3], where sufferers do not produce enough insulin or the insulin they produce does not work properly; also known as insulin resistance. Family history, age or ethnic background might increase a person’s likelihood of getting diabetes, but those who are overweight to obese with a body mass index (BMI) of more than 25 are also more likely to get Type 2 diabetes.

Most staple carbohydrates found in common Asian foods like naan (Indian flatbread) are easily broken down and digested quickly in the small intestine, causing a rapid, high rise in blood glucose

Blood glucose management

In addressing the issues of obesity and diabetes, it is vital to consider the role that blood glucose management plays. A significant number of research findings have shown that increased insulin resistance and the often corresponding elevation of blood glucose levels lead to pre-diabetic conditions. This means that even for people who are not suffering from full-blown diabetes, there is a need for increased awareness of the importance of blood glucose management.

The foods we eat impact our blood glucose levels, particularly carbohydrate-based foods. Most staple carbohydrates found in common Asian foods like naan (Indian flatbread), egg noodles and glutinous rice are easily broken down and digested quickly in the small intestine, causing a rapid, high rise in blood glucose.

The lowdown on resistant starch

Resistant starch, however, is a type of dietary fiber that has beneficial metabolic effects including lowering blood glucose concentrations and improving insulin sensitivity. It is not digested in the small intestine, therefore it does not break down into glucose, and does not cause an elevated insulin response. It passes through the small intestine undigested before reaching the large intestine. Thus, foods that are high in resistant starch produce a lower glycaemic response, with a lower rise in blood glucose and insulin levels.

In a recent clinical trial ^[4] conducted by Barbara Gower, PhD, University of Alabama-Birmingham, using a specific type of resistant starch – derived from a high-amylose maize (HAM-RS) – results show that the ingredient may improve insulin sensitivity. Performed to better understand its effects in insulin-resistant women, it was found that consumption of 30 grams/day of resistant starch improved insulin sensitivity by 23%.

For the study, HI-MAIZE^® 260 corn starch was formulated into snack foods and tested at two doses, 15 g and 30 g resistant starch per day. HI-MAIZE is produced from a proprietary high amylose corn hybrid by Ingredion Incorporated and contains approximately 40% digestible (glycaemic) starch and 60% resistant starch.  

An isocaloric snack formulated with a highly-digestible waxy corn starch served as a control. Participants – 43 healthy normal-weight and obese, pre- and post-menopausal women aged 22 to 68 years – consumed the snack foods for 4-week intervals with a 4-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.

Results showed that HI-MAIZE high amylose resistant starch improved insulin sensitivity in the women with higher insulin resistance; a population that would benefit the most from this effect.

Added to products like bread, HI-MAIZE resistant starch can help promote good digestive health

An effective solution

Besides blood glucose management, other benefits of HI-MAIZE include promoting good digestive health, energy management and enhancing satiety. The food industry has a role to play in helping to educate consumers about healthier eating and provide them with easy, delicious choices that do not fuel the health factors leading to diabetes. The secret then, is to find ways to add natural fiber to everyday foods, without affecting the taste or texture.

Because HI-MAIZE resistant starch is naturally white in appearance, neutral in taste, small in particle size and doesn’t change the taste and texture of food, it can be incorporated into a wide variety of products that appeal to consumers across Asia-Pacific. It can be added to foods such as breads, baked goods and snacks by partly replacing flour, or to smoothies, yoghurt or oatmeal in a simple blending process. This silently boosts consumers’ fiber and resistant starch intake, without negatively impacting their enjoyment of food, and is one route that is sure to pay off for consumers, governments, health authorities and food manufacturers alike.

References

^[1] http://www.idf.org/sites/default/files/EN_6E_Atlas_Full_0.pdf

^[2] http://www.idf.org/diabetesatlas/data-visualisations

^[3] http://www.cdc.gov/chronicdisease/resources/publications/aag/ddt.htm

^[4] Gower B. Beneficial effects of dietary resistant starch in insulin resistant women. Poster abstract presentation at: The Obesity Society Annual Meeting at ObesityWeek^SM 2014; November 2-7, 2014; Boston, MA. www.obesityweek.com.