THURSDAY, Sept. 19, 2002 (HealthDayNews) -- Breast-feeding has long been seen as critical to child development, including when it comes to shielding infants from allergies and asthma later in life.
But a new study of children in New Zealand finds that those who nursed were more likely, not less likely, to grow up with allergies and asthma.
"There are many, many reasons why breast-feeding is good. Preventing asthma and allergies can no longer be included in those reasons," said Dr. Malcolm Sears, a lung expert at McMaster University in Ontario and leader of the research effort.
Ten years ago, Sears said, doctors advised parents afraid of allergies in their kids to get rid of their cat when baby made three and to be sure to breast-feed for as long as possible. "Now we're saying own a cat," but that nursing is no longer part of the equation, he said. Still, he said, "there are 101 reasons to breast-feed," and parents shouldn't consider a lack of protection from wheezing sufficient to avoid the practice.
Sears and his colleagues, who report their findings in the Sept. 21 issue of The Lancet, followed more than 1,000 New Zealand residents for up to 23 years. They assessed their allergy and asthma history with questionnaires, skin tests and lung capacity. Roughly half the subjects had been breast-fed for at least four weeks, and for an average of about five months, while the rest had been given infant formula.
Judging from the results of past studies, these children should have had fewer problems with allergies and asthma as they grew up. But the opposite was true.
Between ages 13 and 21, they were more likely to be allergic to cats, dust mites and grass pollen than the formula-fed children, and at ages 9 and 26 they were more prone to asthma.
The effect held no matter how long the children were nursed and regardless of their parental history of allergies and asthma. It also applied in boys, who are more likely girls to suffer asthma early in life -- though that pattern switches in adolescence.
Sears said it's not clear why breast-feeding might be detrimental to allergies. Nursing is key to bolstering a baby's immune system, and allergies are an immune reaction, but the two processes must differ.
Dr. Jaqueline Worth, an ob-gyn at Lenox Hill Hospital in Manhattan, said the latest study won't change her recommendations to women about the value of nursing. "My patients think that breast-feeding is healthy in general for the baby, and I still feel that way," she said.
Breast-feeding promotes bonding between mother and infant, provides an unparalleled source of nutrition, and helps a woman return to her pre-pregnancy weight by burning calories, Worth said. The American Academy of Pediatrics recommends exclusive breast-feeding for the first six months of a baby's life. The group encourages women to nurse for longer if possible.
What To Do
Learn about the breast-feeding from the American Academy of Pediatrics . For more on allergies and asthma, check out the American Academy of Allergy Asthma and Immunology or the Childhood Asthma Research and Education (CARE) Network.
