Breast-Feeding Seems to Protect Against Some Allergies
MONDAY Jan. 7, 2008 -- Atopic disease -- which includes eczema, asthma and food allergies -- may be delayed or even prevented in high-risk infants if they are exclusively breast-fed for at least four months or fed infant formula without cow milk protein.
That's the conclusion of a new clinical report from the American Academy of Pediatrics (AAP) that's published in the January issue of Pediatrics. The report replaces an earlier policy statement from the AAP.
"Basically, it probably does not matter what pregnant or lactating women eat," said Dr. Frank Greer, an author of the report, professor of pediatrics at the University of Wisconsin and chairman of the AAP Committee on Nutrition.
"The best prevention for atopic [allergic] disease is exclusive breast-feeding for four months," he added. "And if your infant comes from a family with significant atopic disease, then weaning from breast milk to a partially or extensively hydrolyzed [hypoallergenic] formula [without cow milk protein] may delay or prevent the onset of atopic disease, especially atopic dermatitis [eczema]."
Greer added that this recommendation would also apply to formula-fed infants who are at risk for atopic disease.
The timing and introduction of solid foods has no protective effect on the prevention of atopic disease, according to the new report.
"With the increase in asthma and food allergies that we've seen recently, we had hoped that maternal diet, breast-feeding and early childhood diet might all have some factor in decreasing incidence," said Dr. Jennifer Wu, an obstetrician/gynecologist at Lenox Hill Hospital in New York City. "Unfortunately, it doesn't seem to significantly impact, according to studies already done. The only one that seems to be impacted is the atopic dermatitis, which is decreased by about one third by breast-feeding. But the studies that have been done so far have not proven that breast-feeding will significantly impact childhood asthma or food allergies."
The incidence of allergic diseases such as asthma, food allergies and various skin conditions has exploded during the past few decades. In children 4 years of age and younger, the incidence of asthma has risen 160 percent, while the incidence of atopic dermatitis has almost tripled. And the incidence of peanut allergy has doubled just during the past decade, according to the report.
While genetics certainly plays a role in the development of these diseases, environmental factors such as diet are also strongly related.
The new report reviewed different evidence on nutrition during pregnancy, breast-feeding and the first year of life that might affect the development of allergic disease. Its major findings are as follows:
- Currently, there is no evidence that what a mother eats during pregnancy or breast-feeding plays a major role in preventing atopic disease in infants. There is some evidence, however, that avoiding certain foods during breast-feeding may help prevent atopic eczema.
- Exclusive breast-feeding for at least four months for infants at high-risk of developing atopic disease decreases the risk of developing eczema and cow milk allergy during the first two years of life.
- In high-risk infants who aren't breast-fed exclusively for four to six months, the use of hydrolyzed infant formula (as opposed to formula containing cow milk) may delay or prevent the onset of atopic dermatitis.
- Exclusive breast-feeding for at least three months protects an infant against wheezing in early life.
- There is no good evidence to support the use of soy-based infant formula to prevent allergies.
- There is no evidence to suggest that delaying the introduction of solid foods before the recommended 4 to 6 months of age will have an effect on the development of atopic disease.
- There is no convincing evidence to suggest that any dietary intervention will prevent atopic disease after 4 to 6 months of age.
"It's a mixed picture," Wu said. "We don't have proven efficacy for breast-feeding. It may mean that we need more robust studies and a longer-term follow-up for kids."
The new report is titled "Effects of Early Nutritional Interventions on the Development of Atopic Disease in Infants and Children: The Role of Maternal Dietary Restriction, Breastfeeding, Timing of Introduction of Complementary Foods, and Hydrolyzed Formulas."
There's more on infant nutrition at the National Institutes of Health.
Posted: January 2008