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The human brain produces fructose from glucose
Janice J Hwang1, Lihong Jiang2, Muhammad Hamza1
1Section of Endocrinology and.
JCI Insight
|February 28, 2017
Summary
The human brain can produce its own fructose from glucose via the polyol pathway. This endogenous fructose production in the central nervous system (CNS) may influence feeding behavior and metabolic diseases.
Area of Science:
- Neuroscience
- Metabolic Research
- Biochemistry
Background:
- Fructose is linked to obesity and type 2 diabetes.
- Central nervous system (CNS) fructose in rodents stimulates feeding.
- Low plasma fructose levels raise questions about its CNS entry and effects.
Purpose of the Study:
- To investigate endogenous fructose generation from glucose in the human brain.
- To determine the role of the polyol pathway in brain fructose production.
- To assess the relationship between intracerebral glucose and fructose levels.
Main Methods:
- 1H magnetic resonance spectroscopy (MRS) was used.
- Healthy subjects underwent a 4-hour hyperglycemic clamp.
- Intracerebral glucose and fructose levels were measured over time.
Main Results:
- Intracerebral glucose levels significantly increased during the clamp.
- Intracerebral fructose levels also rose significantly.
- Increased brain fructose correlated with increased brain glucose, not plasma fructose.
Conclusions:
- The polyol pathway facilitates endogenous fructose production in the human brain.
- Brain fructose levels are influenced by intracerebral glucose conversion.
- CNS fructose effects may stem from both dietary intake and endogenous production.
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