Ames, Iowa – Starches that take the body longer to digest can have far-reaching health benefits, says researchers.
At Iowa State University, a team of researchers is focusing on digestive resistant starches, which take time for the body to turn into nutrients.
The thinking is that these starches may help to combat obesity, contribute to disease prevention and help humans cope with diabetes.
For example, someone with an average metabolism will digest most of the starch in a piece of white bread in about 20-30 minutes, says Jay-lin Jane, a distinguished professor of Food Science and Human Nutrition.
The researchers are interested in starches that allow humans to continue drawing nutrients from food hours after it’s eaten.
The team is working on ways to substitute resistant starch developed in the lab for wheat flour commonly found in bread, noodles or crackers, says Jane. That way, consumers can experience all the health benefits associated with resistant starches while making relatively modest changes to their buying habits at the grocery store.
How resistant starches work
Resistant starches help to keep blood sugar levels in check and at an even keel. Dramatic spikes in blood sugar can be dangerous for diabetics, explains Mathew Rowling, as assistant professor of Food Science and Human Nutrition.
“White flour turns to sugar almost as soon as it hits the intestine, which causes a quick rise in blood sugar,” says Rowling.
“But if you’ve got a starch that slows down that transition, you can even out the sudden spikes and drops.”
Countless microbes call the average human’s digestive system home at any given time, and most of them are helpful. In exchange for a place to crash, microbes in the colon keep digestion running smoothly by fermenting carbohydrates and proteins to produce short-chain fatty acids, for example.
The research team is studying how resistant starches can uphold the right balance of microbes in the digestive system. One hypothesis is that starches that take longer to digest still retain nutrients when they enter the colon, which is beneficial for the microbes that live there.
Top photo: Resistant starch. Iowa State University website.