This is good news, because producing a high level of insulin can impair our body's ability to burn fat, especially during exercise
Fresno, CA (PRWEB) November 3, 2006
Widely known as a wise fruit choice for their high antioxidant content, all-natural sweetness and dietary fiber, raisins also tout a low to moderate glycemic index (GI), according to new research at The Ohio State University.
The GI -- a measure of how a food affects blood sugar levels -- is being used as a tool in diabetes management, weight loss and sports nutrition. This independent clinical study sponsored by the California Raisin Marketing Board fed California Raisins to 11 people with pre-diabetes, 10 healthy sedentary individuals and 11 endurance athletes. Study results, presented at the annual meeting of Experimental Biology in 2006, showed that the GI of raisins was low in sedentary and pre-diabetic subjects. In athletes, the GI of raisins was moderate. The average GI -- using glucose as the reference food -- of raisins in the study was 54, while most experts use 55 or less as the definition for low GI.
This new research raises questions about 2002 published GI data most often used to construct low GI diets. "The GI of raisins in published tables is 64, higher than that observed in this study," said Julie Jones, Ph.D., Professor of Nutrition at the College of St. Catherine and scientific advisor to the California Raisin Marketing Board. "The U.S. study used more subjects than either the Canadian or Australian data, which are the bases for the numbers in the widely-used GI table," added Jones.
Also, feeding raisins in the study did not cause participants to secrete high levels of insulin. "This is good news, because producing a high level of insulin can impair our body's ability to burn fat, especially during exercise," said Steve Hertzler, Ph.D., registered dietitian and study leader.
A second phase of this study is underway. It will evaluate how a pre-exercise snack of raisins compared with other snacks affects blood sugar and insulin levels in people with pre-diabetes. Earlier California Raisin Marketing Board-sponsored independent studies with children showed that a raisin-nut mixture as a snack before soccer gave children a steady supply of energy during the game. "We assume that raisins will help give a steady supply of energy for adults engaged in exercise, too," said Jones.
The California Raisin Marketing Board was created by a State Marketing Order in 1998 and is 100 percent grower funded. Its mission is to support and promote the increased use of California-grown raisins and sponsor crop production, nutrition and market research. California's San Joaquin Valley produces the highest quality raisins in the world. Nearly 4,000 raisin growers reside in this fertile valley 240 miles long and 50 miles wide.
For a copy of the research study highlights composed by Dr. Steven Hertzler, visit http://www.calraisins.org/nutrition/research.cfm, and scroll down to number 12 to view the PDF version of the results entitled "Determination of the Glycemic and Insulinemic Indexes of Raisins in Three Populations."