A researcher with the Children's Nutrition Research Center in Houston, Texas, may have an insight on a tragic medical mystery that some pediatricians call "paradoxical re-feeding response." The problem: Some malnourished children die during treatment instead of being revived.

Buford Nichols, a pediatrician at the Houston center, headed a study that suggests prolonged hunger in infants may suppress part of the genetic coding for lactase. This enzyme digests the milk sugar lactose. Nichols' study is the focus of an article just published in the medical journal Gastroenterology.

The Houston center is administered jointly by USDA's Agricultural Research Service and Baylor College of Medicine.

Most starving children and infants respond well to international treatment efforts. But 10 to 20 percent get sicker and die. If Nichols' findings are validated by other similar studies, they may generate discussion among physicians on the value of lactose-free treatments when others don't succeed. This hunger-related intolerance appears fundamentally different from genetically inherited lactose intolerance. The difference appears to occur on the cellular level. The good news: Unlike adult lactose intolerance, this condition is temporary. It abates after the child receives adequate nutrition.

Nichols found the cellular lactase connection by studying 29 infants recovering from malnutrition at a clinic at the University of Sao Paulo in Brazil. The infants had not responded well to re-feeding formulas, but intestinal biopsies ruled out diseases that might have affected recovery.

Nichols compared tissue samples from the malnourished infants to those of 10 well-fed infants hospitalized for a life-saving surgery that required removal of some intestinal tissue. The comparison led Nichols to his conclusions.

Lactose can come in many forms -- from human breast milk to some nations' international food- relief products. USDA's Farm Service Agency, on the other hand, provides lactose-free corn-soy or wheat-soy blends for U.S. relief efforts overseas.

Scientific contact: Buford Nichols, ARS Children's Nutrition Research Center at Baylor College of Medicine, Houston, Texas, phone (713) 798-7018, fax (713) 798-7057, bnichols@bcm.tmc.edu.