Breast-Feeding May Cut Obesity In Childhood

By Marc Kaufman
Washington Post Staff Writer
Wednesday, May 16, 2001; Page A01

Babies who are breast-fed are less likely to become severely overweight as they grow through childhood, according to a major study released yesterday.

The study of more than 15,000 pre-adolescents found that those who were formula-fed as infants were 22 percent more likely than breast-fed babies to be obese or overweight by the time they reached ages 9 to 14. The study, conducted by Harvard University researchers, also found that the longer an infant was breast-fed, the less likely he or she would be overweight.

A second study of 2,685 younger children ages 3 to 5 by researchers at the National Institutes of Health also found that breast-feeding might help reduce the risk that children would become overweight but concluded the effect was minor.

Nevertheless, taken together, the two studies offer compelling evidence that breast-feeding helps protect against weight problems later in life, other researchers said.

"These studies offer another good reason to breast-feed -- it reduces the risk of overweight in the child," said William Dietz of the federal Centers for Disease Control and Prevention, who wrote an editorial accompanying the studies in today's Journal of the American Medical Association.

"The effect may not be terribly large," he said. "But we don't have many good strategies to combat the epidemic of obesity we're seeing, and breast-feeding seems to offer some benefit."

Medical and public health officials have long advocated breast-feeding because of its proven health benefits for children, and possibly mothers, too. These two studies -- among the largest every undertaken on the subject -- are the first in the United States to find a connection between breast-feeding and protection against becoming overweight.

The prevalence of breast-feeding has increased in the past decade and almost 65 percent of mothers nurse their infants during the first week of life.

But federal statistics show that only 29 percent of infants are still breast-fed at 6 months -- the minimum amount recommended by the American Academy of Pediatrics.

While Dietz of the CDC hailed the studies as indicating that "breast-feeding has a protective effect against obesity," the lead researchers of the two studies disagreed over the implications of their findings.

Matthew W. Gilman of the Harvard Medical School said that the results showed that breast-feeding, even for a short time, had a positive impact on the child's later weight. He said the fact that the children in his study were already pre-adolescents gave him greater confidence that the connection was scientifically sound.

But Mary Hediger of the National Institute of Child Health and Human Development at the NIH said her research did not show a strong link between formula-feeding and the heaviest children. In addition, she did not find that length of breast-feeding had an impact on later weight. The most important factor in determining whether a child will be overweight is the weight of the mother, she found.

"In terms of policy implications, promoting breast-feeding as an obesity prevention activity will probably be less effective than developing programs to teach families how to raise a healthy child," she said. "If mothers think they can let their kids sit in front of the TV and eat McDonald's because they were breast-fed when they were babies, they're wrong."

Excessive weight in children has become an increasingly important public health issue because rates of excess weight and obesity have skyrocketed. While 4 percent of children aged 6 to 11 were overweight in the mid-1970s, the CDC recently announced that 13 percent of that age group was overweight in 1999. Similar increases have been found worldwide.

Being overweight in childhood has been associated with an increased risk of diabetes, heart problems and lower self-esteem. Research has also found that once a child becomes overweight, it is very hard lose those extra pounds.

It remains unclear exactly how breast-feeding might protect against becoming overweight. But mothers who breast-feed may be better able to tell when their babies are full, researchers said. The nursing relationship might then lead to less overfeeding and better self-regulation by the growing child.

In addition, previous research has suggested that breast-fed babies have lower levels of insulin -- a hormone that promotes fat storage -- than formula-fed children.

The infant formula industry agrees that breast milk is the best food for babies, and a spokeswoman said yesterday that the new studies indicate that breast-feeding "might help to reduce the risk of having overweight children."

But Mardi Mountford, executive director of the International Formula Council, which represents most formula makers, said the studies were somewhat contradictory and not conclusive. "I think it's very important to keep in mind that while breast-feeding might help, there are many other factors in the home environment that contribute to childhood overweight," she said.

Deitz said that other research has shown that many mothers stop breast-feeding because they are returning to a work, where nursing is not encouraged or comfortable. In his editorial, he wrote that removing barriers to continued breast-feeding at work "may represent one of the policy shifts necessary to help address the obesity epidemic."

© 2001 The Washington Post Company

 

 

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