Lactose Intolerance and Galactosemia

Lactose Intolerance

Lactose Intolerance

Lactose is the predominant carbohydrate found in breast milk. It is a dissacharide composed of one galactose sugar and one glucose sugar. The enzyme lactase hydrolyzes lactose into the two simpler sugars. A person who is truly lactose intolerant will lack the enzyme lactase and they will not be able to break down lactose.

Lactose intolerance is relatively common in adults because many people stop producing the enzyme lactase by age 2 to 5. For example:
    – 90% of Asian adults are lactose intolerant
    – 50% of Hispanics adults are lactose intolerant
    – 10% of White American adults are lactose intolerant

However, it is very very rare that infants are lactose intolerance. If you are told that your baby is lactose intolerant, then you should consult another doctor before you abandon breastfeeding. According to this article, food allergies in babies are often mis-diagnose as lactose intolerance.

If your baby is lactose intolerance, and cannot metabolize lactose, then baby formulas are a savoir! There are soy-based formulas and lactose-free formulas. You can read about baby formulas here but be sure to ask your doctor which is best for your baby.


Another pertinent metabolic deficiency is galactosemia.. A person with galactosemia cannot break down galactose (which is one of the sugar units in lactose). Normally, galactose is converted to another molecule of glucose. the two glucoses are then further broken down to carbon dioxide, water, and energy. The conversion of galactose to glucose requires 3 enzymes. Defects in any one of the 3 enzymes will result in one of the three types of galactosemia. Galactosemia occurs about 1 per 47,000 births (or 1 per 85,000 births in USA).

If your baby has galactosemia, then you will need to feed him a soy-based baby formula. Get more information from
    – Parents of Galactosemic Children
    – the Galactosemia Association of the NE States

lactose intolerance and breastfeeding

Lactose is broken down to carbon dioxide, water, and energy. If you are lactose intolerant, you cannot break lactose into galactose and glucose (shown with red “X”). If you are galactosemic, you cannot convert galactose to glucose. There are three enzymes that can be defective (shown with three red “X” marks).