The carbohydrates in the foods you eat break down into simple sugars as you digest them. As these sugars enter your bloodstream, they cause your body to release insulin, a hormone that allows dietary sugars to enter your cells and provide energy. If sugars enter your bloodstream rapidly, your insulin levels may spike, leading to potential long-term health issues if this is a consistent pattern in your diet. The glycemic index measures how quickly a food boosts your blood-sugar levels. Fruit juice concentrate, although high in sugar, has a low to medium glycemic index.
Glycemic Index
Nutritionists measure a food's glycemic index by comparing how quickly a given amount of a carbohydrate-containing food raises your blood sugar levels compared to the same amount of pure glucose. Glucose has a glycemic index of 100. Foods scoring 70 or more count as having a high glycemic index, while a score of 55 or less means the food has a low glycemic index. Because some food sugars raise your blood sugar levels more than others, you cannot determine a food's glycemic index strictly by how much sugar it contains. Rather, you must take into account the type of sugar. For example, many fruits, including fruit juice concentrate, are rich in fructose, and this fruit sugar, while sweet, does not cause much elevation in your blood sugar levels.
Glycemic Load
Despite the usefulness of the glycemic index, this measure does not take into account the amount of digestible carbohydrate a given amount of food contains. A food with a high glycemic index may actually deliver only a small amount of sugar to your bloodstream with little spike in insulin. Glycemic load measures both the glycemic index and the amount of digestible carbohydrate of a given amount of food. Foods with a high glycemic load score 20 or higher; foods scoring 10 or less have a low glycemic load. Foods that score between 11 and 19 offer a medium glycemic load. Fruit juice concentrates score on the low or low-medium end of this scale.
Fruit Juice Concentrate
Fruit juice concentrate consists of the liquid extracted from whole fruits that then has much of its water content removed, often by heat treatment. The resulting concentrate, which may be stored frozen or in sterile packs, undergoes reconstitution with water before consumption. The Glycemic Index Foundation of the University of Sydney states that reconstituted orange juice has a glycemic index of 53 or 54 and a glycemic load of 10 or 11. Apple juice, reconstituted from concentrate,offers glycemic index and glycemic load values of 39 and 10, respectively.
Considerations
Glycemic index and glycemic load tables do not list values for actual fruit juice concentrates, only for reconstituted fruit juices. Consuming the concentrate itself may increase its glycemic load compared to the reconstituted juice because of the high dose of concentrated sugars you ingest.
References
- Harvard School of Public Health; Carbohydrates: Good Carbs Guide the Way; 2011
- "The American Journal of Clinical Nutrition"; International Table of Glycemic Index and Glycemic Load Values: 2002; Kaye Foster-Powell, et al.; July 2002
- U.S. Food and Drug Administration; Guidance for Industry: Juice HACCP Hazards and Controls Guidance First Edition; Final Guidance; March 2004
- University of Sydney Glycemic Index Foundation; GI Database; March 2010
