Galactose is a simple sugar, a monosaccharide that is also called “brain sugar”. It shares the same molecular formula as glucose, but differs in the structural arrangement of its atoms. Galactose combines with glucose to form lactose (milk sugar) and is about one-third as sweet as sucrose.
Galactose is found in a wide variety of foods, especially in dairy products, lactose in milk being its main dietary source. It commonly occurs in certain pectins, gums and mucilages. Other sources include sugar beets, a large number of fruits such as apple, banana, cherry and grapes, among others. Vegetables containing galactose include broccoli, carrot, cabbage, cauliflower, tomato, peas, pumpkin and spinach, among others.
Galactose provides energy for bodily functions, but must be converted into glucose by the liver before it can be utilised by the body. Apart from providing energy to the body, it has an important role in cell communication. It is also synthesised by the body and forms part of glycolipids (carbohydrates containing lipids) and glycoproteins (carbohydrates containing proteins) and galactolipids that occur in the brain and other tissues of most animals.
- Appears to enhance wound healing.
- Stimulates calcium absorption.
- Research indicates role in lowering the risk of cataract development.
- Is a nutritive sweetener as it provides calories.
- Studies indicate role of galactose in preventing and correcting arthritis.
- As a part of brain tissue, studies indicate its role in long-term memory formation.
- Vital in reproduction since it appears to help in the formation of sperm.
- Role in kidney function.
- Dietary galactose is important in maintaining normal bacterial flora in the intestines. This strengthens a body's digestive abilities.
Galactose is required for a number of functions in the body. However, some people are unable to utilise galactose, giving rise to a condition called “galactosemia”, meaning “galactose in the blood”. Persons with galactosemia are deficient in the enzyme that breaks down galactose in the body. As a result, there is build up of galactose in the bloodstream and tissues. If untreated, it leads to lot of problems in infants and children, such as:
- Liver disease.
- Kidney problems.
- Brain damage leading to death in some cases.
- Learning disabilities.
People suffering from galactosemia can very well enjoy good health and lead independent lives with proper dietary management. Since these people cannot utilise galactose in the body, the treatment includes removal of all foods containing galactose from the diet. The main dietary source being milk and milk products, people with galactosemia should not include these in their diet. The restriction of galactose-containing foods should be followed all through life.
As the condition requires life-long abstinence from milk and milk products, calcium supplementation is recommended. Also, soy formula or other lactose-free formula can be fed to the infant to ensure healthy living.
Since galactosemia is an inherited enzyme disorder, knowledge of family history is necessary. Genetic counselling to parents will help them in making an informed choice about pregnancy and prenatal testing.