Galactosemia - nutritional considerations

Alternative names

Inborn errors of metabolism; Fructose intolerance - nutritional considerations; Maple sugar urine disease (MSUD) - nutritional considerations; Phenylketonuria (PKU) - nutritional considerations; Branched chain ketoaciduria - nutritional considerations

Definition

Inborn errors of metabolism are rare genetic disorders in which the body cannot turn food into energy (metabolize food) normally. The disorders are usually caused by defects in the enzymes involved in the biochemical pathways that break down food components.

Side Effects

The food product that is unable to be metabolized (broken down into energy) can build up in your body and cause a wide array of symptoms. Several inborn errors of metabolism cause mental retardation if not controlled. Please see each specific disease for exact symptoms.

Recommendations

Inborn errors of metabolism often demand diet changes. The type and extent of the changes depends on the specific metabolic error. Registered dietitians and physicians can help with the diet modifications needed for each disease.

The following are some examples of inborn errors of metabolism.

Fructose intolerance:

• A genetic disorder in the breakdown of the carbohydrate fructose. It is potentially life threatening but may be treated by diet changes.
  
• Food sources of fructose include fruits, fruit juices, sucrose (all sugars - cane, beet, white, brown, etc), corn syrups, honey, sorbitol, levulose, invert sugar, and some vegetable and starches.
  
• All fructose should be avoided in the diet. The severity of the restriction depends on individual tolerance. Sugar and fructose are found in many foods, making the diet difficult to follow.
  

Galactosemia:

• A genetic disorder in the breakdown of the carbohydrate galactose to glucose. It can result in cataracts, enlarged liver, enlarged spleen and mental retardation. Typically, the disease is found in milk-fed infants shortly after birth. This is because milk contains large amounts of galactose.
  
• Food sources of galactose include mammalian milks, dairy products and foods containing them.
  
• It is recommended that milk and milk products should be avoided, including yogurt, cheese, ice cream. Galactose and lactose free milk substitutes and foods should be used. Other sources of galactose may include sugar beets, gums, seaweed, flaxseed, mucilage, whey, some vegetables, etc. Women who carry the genetic trait should also follow the diet since galactose may cause mental retardation to the fetus. Contact a Registered Dietitian for complete information on a galactose free diet.