Potatoes and other high-GI foods may not be dietary villains after all, NZ study

Posted by AFN Staff Writers on 12th October 2011

potatoes-20060407-02Potatoes and other foods reportedly high on the Glycemic Index (GI) might not be the dietary villains that many dieticians claim them to be, according to a new study by the University of Otago, in New Zealand.

The findings, published today in the American Journal of Clinical Nutrition, were from Dr Bernard Venn and colleagues from Otago’s Department of Human Nutrition, who studied 30 healthy adults aged between 18 and 50. They found that despite potato being a high-GI value food, a meal containing potato may not necessarily have a high-GI value.

The Glycemic Index is a measure of the effects of carbohydrates on blood sugar levels. Carbohydrates that break down quickly during digestion and release glucose rapidly into the bloodstream have a high GI; carbohydrates that break down more slowly, releasing glucose more gradually into the bloodstream, have a low GI.

In the study, the GI values of three meals were tested. The meals all contained chicken, peas, carrots, kumara and gravy, together with a starchy staple food varying between potato, white rice or spaghetti.

The researchers found that the GI value for each meal was not as high as they anticipated. Based on the GI values of the foods used in a potato meal, the researchers expected that the meal would have an overall GI value of 65, which falls within the medium range. However, the meal fell just within the low range with a GI value of 53.

Dr Venn commented, “I don’t think people should be too afraid of putting high-GI foods into their meals – our work suggests that having a small amount of potato with a meal isn’t going to drive your blood sugar crazy.”