In brief: Galactose is a monosaccharide and, together with glucose, forms lactose. After milk sugar is digested, galactose is processed mainly in the liver.
How is galactose processed?
| Step | Interpretation |
|---|---|
| Lactose digestion | Lactase splits lactose into glucose and galactose |
| Liver metabolism | Galactose is processed through the Leloir pathway |
| GALT enzyme | Central in classic galactosemia |
| Galactosemia | Rare inherited metabolic disorder |
Where is galactose found?
The main dietary source is lactose in milk and dairy foods. Smaller amounts of free or bound galactose occur in other foods.
What is classic galactosemia?
In classic galactosemia, GALT activity is usually severely reduced. Toxic metabolites can accumulate, and newborns may become seriously ill after milk feeding.[1]
Do not confuse it with lactose intolerance
Lactose intolerance is caused by insufficient lactase in the intestine. Galactosemia is a rare inherited disorder of galactose metabolism.
FAQ
Is galactose a sugar?
Yes, a monosaccharide.
Is galactose the same as lactose?
No. Lactose is made of glucose and galactose.
Is galactose dangerous for healthy people?
Not in normal food amounts.
What is galactosemia?
A rare inherited metabolic disorder in which galactose cannot be processed normally.
Conclusion
Galactose is a normal part of carbohydrate metabolism. The key medical exception is galactosemia, which must be clearly distinguished from lactose intolerance.
