Parents in the study received standard nutrition counselling. ((Mel Evans/Associated Press))

Pediatricians can help parents wean their babies off feeding from a bottle sooner, a new Canadian study suggests.

Prolonged bottle feeding beyond 15 months to two years of age has been linked to excessive milk intake and iron deficiency.

Children who are iron deficient are more likely to show behavioural problems, less likely to do well in school, more likely to have tooth decay and — in rare cases — more likely to have a stroke as a child, said the study's lead author, pediatrician Dr. Jonathon Maguire of St. Michael's Hospital in Toronto.

In Monday's issue of the journal Pediatrics, Maguire and colleagues at Toronto's Hospital for Sick Children reported children were half as likely to be using a bottle to drink milk and juice at two years of age if their parents were introduced to a week-long weaning protocol.

"We took five minutes out of the nine-month well-child visit and we told parents essentially to stop using the bottle because it was bad for their children," Maguire said. "The parents did it. It worked."

Limit drinks

In the randomized controlled trial, 201 children were monitored up to two years of age. Between January 2006 and 2007 when the infants were nine months old, they were randomly assigned to either an intervention group or a control group.

Parents in the intervention group were given a "sippy cup," instructions on using the cup to wean, and education about the risks of continued bottle use. Unlike with a bottle, it's harder for babies to drink too much milk or juice from a sippy cup, Maguire said.

Parents in the control group received standard nutrition counselling, such as when to start feeding solids and avoiding nuts, honey, shellfish, egg whites and foods that are difficult to swallow, to prevent allergies and choking.

Children in the intervention group started using a cup three months earlier on average, the researchers found.

The study's authors initially expected that the children in the intervention group would show a decrease in iron depletion at two years of age, but there was no significant decrease in levels of iron deficiency between the two groups.

Iron-deficiency levels may not have changed because the parents in the intervention group were in a well-educated population, where 12 per cent of the children showed iron deficiency, compared with about 30 per cent of toddlers in Ontario, McGuire said.

About 86 per cent of parents whose children were still using the bottle after age two said it was because the child preferred the bottle over the sippy cup. There seems to be a window when it's easier to change a child's behaviour. As they get older, it becomes harder, the researchers said.

Maximizing time with doctor

The findings are important for both parents and doctors, McGuire said, noting parents get about eight minutes of time with a pediatrician during an office visit.

"Of those eight minutes, its important to know what things you should be told, and doctors want to know what things they should tell you. So studies like this that demonstrate whether a piece of advice works or not is very important to be able to maximize the use of that time," he said.

In the study, research assistants performed the "placebo counselling" sessions so that neither the pediatricians nor parents would know who was involved in the intervention and prevent bias in interpreting the results.

The unexpectedly low prevalence of iron depletion in the control group, 17 per cent, might have resulted from the positive effect of placebo counselling on the importance of iron, the study's authors suggested.

The American Academy of Pediatrics recommends complete bottle weaning for healthy children by 15 months of age, but many parents choose to feed their children by bottle for longer. There is no official Canadian guideline, and Canadian and U.S. surveys of pediatricians have found a wide variety of recommendations.

The research was funded by a grant-in-aid from the Danone Institute of Canada, the Hospital for Sick Children and the Canadian Institutes for Health Research.