It is usually not necessary to eliminate dairy foods from the diets of lactose-intolerant children and adolescents, and doing so may compromise their long-term skeletal health.
Most of these patients still can consume enough dairy every day to meet their calcium and vitamin D needs, especially if they drink lactose-reduced milk and eat yogurt with live cultures and/or aged cheeses, like cheddar or Swiss, according to the American Academy of Pediatrics' new guidelines on lactose intolerance.
If dairy products are eliminated from the diet of these children, the AAP strongly recommends regular calcium supplements. However, the guidelines said, supplemental calcium is not as bioavailable as that contained in mammalian milk.
The report also noted that, although the gastrointestinal distress of true lactose intolerance is unpleasant, is not harmful. However, when such symptoms occur in newborns or children who are younger than 3 years old, they should be immediately investigated as they may signal a serious, even life-threatening, digestive disorder.
The document is the first AAP lactose guideline update since 1990 (Pediatrics 2006;118:1279–86).
A statement from the American Dairy Council hailed the AAP guidelines as a common sense approach to a problem that sometimes prevents children from getting milk's unique nutritional package of protein, vitamins, and minerals.
“Although calcium-fortified beverages and other foods can provide an alternative source of calcium, the report reinforces that they do not provide an equivalent nutrient package to dairy foods like milk, cheese, and yogurt,” Ann Marie Krautheim, a registered dietitian and an official on the council, said in a statement.
“We hope this report will further educate parents on how to continue to include dairy in the diets of children sensitive to lactose and also help improve their nutrient intake.”
Symptoms of lactose intolerance usually emerge slowly over several years and are most common among Asians and Native Americans, followed by blacks and Hispanics. The incidence is very low in whites, whose northern European heritage seems to be protective, according the guidelines. Among white children, symptoms typically don't develop until after age 4 or 5 years; they may manifest earlier in other groups.
Newborns who develop intractable diarrhea after consuming any mammalian milk product, including human milk, may have congenital lactase deficiency, a life-threatening inability to digest lactose. A biopsy of the small intestine will show normal histology but low or absent lactase concentrations. Unless this disorder is recognized and treated immediately, fatal dehydration from diarrhea is possible. Treatment is simple—feed the child a commercial lactose-free formula, the guidelines said.
When lactose-intolerance symptoms appear, the most common reaction is to remove dairy foods from the diet completely. However, that may be a mistake, the guidelines noted.
“The avoidance of milk products to control symptoms may be problematic for optimal bone mineralization. Children who avoid milk have been documented to ingest less than the recommended amounts of calcium needed for normal bone calcium accretion and bone mineralization.”
Most lactose-intolerant children can tolerate varying amounts of dairy, depending on their individual symptoms: One glass of milk may be fine, but two may provoke diarrhea.
Parents should be encouraged to feed children lactose-free or lactose-reduced milk, and to encourage them to enjoy cheese and yogurt with live bacterial cultures, according to the guidelines. Yogurt and cheese may be especially valuable for very sensitive children, since the firmer textures of these foods delay gastric emptying and intestinal transit time, which results in fewer symptoms.
The guidelines also pointed out that all mammalian milks contain lactose, so there is no advantage in switching from cow milk to goat milk.
In addition, they said, rice and soy milks are not good substitutes, because they are lacking in nutrients that are needed for bone growth.