Dietary fibre can improve your sense of wellbeing.
Increasing resistant starch in grains to improve bowel health
The Food Futures Flagship is investigating the dietary benefits of resistant starch and developing commercial grain varieties that are high in resistant starch.
12 July 2006 | Updated 12 January 2012
What are starch and resistant starch?
Starch is a carbohydrate polymer made up of glucose. It is produced by plants and is a major source of nutrition for humans.
Most starch in food is broken down into glucose by the small intestine and absorbed into the body.
However, resistant starch — or indigestible dietary starch — escapes digestion in the small intestine and passes into the colon. There it is broken down by the resident bacteria releasing short chain fatty acids (SCFA) with the potential to promote bowel health and reduce the risk of developing colon diseases.
In some foods, such as legumes the content of resistant starch may be as high as ten per cent. However, in most modern processed foods, resistant starch level are very low, which may contribute to large bowel disfunction.
Diets high in resistant starch have been associated with improved bowel health and a reduction in the risk of colorectal cancer.
The research has the aim of producing high resistant starch foods through the generation of new cereals.
It has shown already that high-resistant starch wheat is viable. An experimental wheat variety has been created by using RNA interference (RNAi) to prevent the wheat from producing two starch-branching enzymes. This raised the level of the resistant starch amylose from about 25 to 70 per cent of the total starch in the wheat.
Researchers are building on this work by searching for naturally occurring genes in wheat that can increase the levels of resistant starch. This information will be used to selectively breed new wheat varieties that are high in resistant starch, without having to modify the plants’ genes.
Researchers are also:
exploring the health benefits of resistant starch, through trials in humans and animals
investigating how high resistant starch affects the commercial properties of wheat and wheat products, such as processing and cooking.
This project is part of the Food Futures Flagship. It is supported by grain industry expertise from Grain Research and Development Corporation (GRDC) and the French biotechnology company Biogemma. Biogemma also provide expertise in the food industry.
The project aims to create commercial wheat varieties that are high in resistant starch and to improve the understanding of the role of resistant starch in bowel health.
Diet-related non-infectious diseases, such as colorectal cancer, heart disease and diabetes, are some of the most serious health problems in the developed world.
High resistant starch wheat can be incorporated as wholegrain into breads, cereals and other foods. By reducing the food’s glycaemic index and improving the digestive process, the new wheat could help reduce the risk of:
Within CSIRO, this research is carried out by a team lead by Dr Regina Ahmed. The team includes staff from CSIRO Plant Industry and the Food Science Australia joint venture.
Find out more about our work with Future grains, grain based foods and feed.