Quest for Low GI Potato

Canadian Researchers Developing Diabetes-friendly Spud

<Organizers of the 2010 Olympic and Paralympic Winter Games will be rising to the challenge of providing high-quality, nutritional food for the more than 10,000 high-performance athletes set to converge on Vancouver.

Olympic athletes need a lot of extra fuel in order to perform well. Fresh fruits and vegetables will figure among the many healthy choices served, including a Canadian staple, potatoes. Rich in potassium and Vitamin C, potatoes are the subject of new interest among both scientists and nutrition-conscious consumers.

Around the world, an estimated 246 million people are affected by diabetes. This metabolic disorder does not discriminate by age, gender or race and, on average, seven million more people will be diagnosed with diabetes every year. By 2025, the Canadian Diabetes Association projects 380 million people worldwide will have the chronic health condition.

Prevalent rates of type 2 diabetes especially have been escalating throughout the world, to an extent that the condition is considered to have reached epidemic proportions in many countries, particularly westernised nations. Dietary and lifestyle change are accepted as important contributions to the prevention and management of conditions such as type 2 diabetes, as well as coronary heart disease, obesity and certain cancers. For people with diabetes, who cannot or have only limited ability to process glucose, it is essential that they take dietary steps to control their blood glucose, or blood sugar level.

Because the body converts carbohydrates into glucose, diabetics must be careful about the amount and type of carbohydrates in their diet. To help people with diabetes make the best choices on carbohydrates, researchers have developed the Glycemic Index (GI), which has been gaining popularity and scientific support from major diabetes organizations throughout the world. The GI ranks carbohydrates based on the rate at which they affect blood glucose levels,

A recent United Nations Food and Agriculture Organization and World Health Organization report recommends the bulk of carbohydrate-containing foods consumed should be those rich in non-starch polysaccharides and with low GI. Of course, this also means limiting intake of foods with higher GI, including the immensely popular potato.

Believing that no one should have to deny themselves the benefits of potatoes, researchers from Agriculture and Agri-Food Canada (AAFC), the University of Guelph and the University of Toronto are now in the second year of a three-year study aimed at identifying a low GI potato.

Dr. Benoit Bizimungu, lead research scientist from AAFC, says, “Low GI and high dietary fibre foods have the potential to provide benefits not only in diabetes, but also in obesity, and bowel health.”

This advancing Canadian research is aimed at developing new potato germplasm that is high in slowly digestible or resistant starches and fibre content.

“Although raw potato is hardly digestible, cooked potato contains high levels of rapidly available glucose,” says Dr. Bizimungu. “Increasing the amount of resistant or slowly digestible carbohydrates could potentially have positive health benefits for the consumers.”

Genetic variation in the GI potential of different potato selections will be evaluated, as well as how the GI of the potato is affected by growing conditions, and how the potato’s GI changes during storage and different methods of preparation. Researchers are investigating basic information on starch biochemical, structural and rheological properties in relation to the different textural characteristics of potato germplasm. In vitro systems and animal studies will also be used to assess GI potential of elite clones and potential benefits in the areas of bowel health and diabetes. The study will be further complemented by GI studies with human volunteers. 

Funding for the study is provided by AAFC’s Agricultural BioProducts Innovation Program. Once the research has been completed, the low GI potato selection will be available through the Accelerated Release Program, a two-phase process to fast track the release of promising potato selections developed at AAFC’s Potato Research Centre in Fredericton, New Brunswick.