Glucose is a sugar made of a single sugar unit that is ubiquitous in the food supply and a key player in human and plant metabolism. In human metabolism, glucose is responsible for providing energy. Although it's necessary to support human life, too much glucose in the diet has been associated with health complications such as obesity, diabetes, cardiovascular disease and cancer. Following dietary guidelines to ensure that sugar intakes are within a healthy range is a good way to avoid these problems. Individuals with diabetes need to be particularly careful about how much glucose and other sugars they consume.
Glucose is a byproduct of the process of photosynthesis that plants undergo to provide themselves with energy. As a result, many plants, particularly fruits, are high in glucose. Examples of fruits high in glucose include bananas, grapes, kiwi, cherries and persimmons. Dried fruits are particularly high in glucose because of their low water content. According to the United States Department of Agriculture Nutrient Database, Medjool dates have the highest glucose content among dried fruits. The most potent source of glucose is honey, with a higher glucose content than any other sweetener, with the exception of artificially manufactured glucose.
Foods Digested as Glucose
Foods high in starch and smaller sugars such as lactose are eventually digested to generate glucose. This is because they are composed of glucose and other single sugar units like galactose that are connected by special bonds, rather than free glucose, which is unbound. Foods high in starch include corn, rice and potatoes. Foods high in lactose include most dairy products such as milk, butter and yogurt. Just because these foods are not high in free glucose doesn't mean that they won't raise blood sugar.
Glucose Supplements and Added Sugars
Glucose supplements are not commonly used, with the exception of high-performance athletes who use them to maintain energy during long endurance activity. Many foods have added sugars, including glucose, such as soft drinks, cereal, granola bars and commercial baked goods. The American Heart Association suggests that you consume no more than 100 calories per day from added sugars, so you should avoid these types of foods.
No specific guidelines exist for glucose intake for healthy individuals, so follow the guidelines for overall carbohydrate intake suggested by the Institute of Medicine. The current recommendations are to consume between 45 and 65 percent of your daily total calories from carbohydrates, emphasizing fruits, vegetables and whole grains, and minimizing added sugars.
- Advanced Nutrition and Human Metabolism; Gropper, S. and Smith, J.
- United States Department of Agriculture: Nutrient Database
- Krause's Food and the Nutrition Care Process; Kathleen Mahan, L. et al.
- Medicine and Science in Sports and Exercise: CNS Fatigue and Prolonged Exercise: Effect of Glucose Supplementation
- Harvard School of Public Health: Added Sugars in the Diet