Research reveals digestive benefits of resistant starch
December 01, 2005
by FoodBusinessNews.net Staff
Resistant starch’s effect on blood sugar levels and satiety has caught the attention of some grain-based foods manufacturers. According to recent research, resistant starch could also reduce risks of colon cancer and diarrhea — benefits worth promoting.
David Topping, Ph.D., chief research scientist for the Commonwealth Scientific and Industrial Research Organization (CSIRO) at Adelaide, Australia, spoke about such findings at the recent "Making Fiber Irresistible: Resistant Starch is a Natural" conference in Chicago. The conference was organized by National Starch Food Innovation, Bridgewater, NJ, and Oldways Preservation Trust, Boston, MA.
Resistant starch provides digestive benefits in a different way than regular fiber, according to Dr. Topping. While fiber works in a bulking manner, resistant starch produces short-chain fatty acids, especially butyrates, that aid in fermentation. Butyrates can inhibit a range of cancer cells including colorectal cancer cells, Dr. Topping said.
"Butyrate is being treated almost like a drug," Dr. Topping said, because it can repair damaged DNA.
He described a population study in South Africa showed that resistant starch may reduce colon cancer. White people in the country had a higher fiber intake than blacks, but they also had a higher incidence of colonic cancer and a lower concentration level of butyrate. Blacks in South Africa ate more starch, such as in porridge, and had a higher concentration of butyrate. "We think they are eating a lot of resistant starch," Dr. Topping said.
Resistant starch comes in four forms. Physically inaccessible starch (RS-1) can be found in milled grains and legumes. Granular starch (RS-2) is found in foods like green bananas, raw potatoes and high-amylose corn. An example of gelatinized and retrograded starch (RS-3) is cooled potato starch. Chemically modified starch is called RS-4.
National Starch Food Innovation promotes five health benefits in its Himaize 5-in-1 fiber, a form of RS-2 resistant starch. Digestive health is listed as the fourth benefit.