Wednesday, June 24, 2009

Study finds living near fast food outlet not a weighty problem for kids

A new study by Indiana University-Purdue University Indianapolis (IUPUI) researchers contradicts the conventional wisdom that living near a fast food outlet increases weight in children and that living near supermarkets, which sell fresh fruit and vegetables as well as so called junk food, lowers weight.

The IUPUI investigators in economics, pediatrics, geography and urban planning compared children's weights over time before and after one of these food purveyors moved near the children's residences. Living near a fast food outlet had little effect on weight and living near a supermarket did not lower it.

The IUPUI researchers also report that residing near certain recreational amenities -- fitness areas, kickball diamonds, and volleyball courts -- lowers children's body mass indexes (adjusted for normal childhood growth). The researchers estimated that locating one of these facilities near the home of an overweight eight-year-old boy could lower his weight by three to six pounds. Surprisingly, living in proximity to a track and field facility (typically on the campus of a middle or high school) was associated with weight gain.

Reducing obesity in children is a high priority in health care and public policy, yet its causes and, consequently, what medical interventions might be effective, are not well understood.

"This study contradicts anecdotal information and provides scientifically verified insights into a wide range of variables that we hope will help physicians and public policy makers fight childhood obesity more effectively," said the study's first author Robert Sandy, Ph.D., professor of economics and assistant executive vice president of Indiana University.

The IUPUI research, published in the National Bureau of Economic Research's Economic Aspects of Obesity, utilized electronic medical records of visits over 11 years to pediatric clinics in inner city Indianapolis to determine the effects on body mass of environmental changes, such as the opening or closing of a convenience store or the installation of a playground or opening of a recreational trail.

The researchers looked at data for more than 60,000 children between the ages of 3 and 18. The children were 53 percent African-American, 30 percent Caucasian and 12 percent Hispanic. Most were poor, and publically insured.

The effect of each environmental change, for example the closing of a fast food establishment or installation of a baseball diamond, was studied at 0.10 mile, 0.25 mile, 0.50 mile and 1.00 mile from a child's residence.

Earlier studies typically have looked at one moment in time, the so-called snapshot approach, not a decade-long expanse of data. "Previous studies did not benefit from the wide range of information we acquired such as details of both sick and well doctor visits, changes in a child's address, annual food service establishment inspection data, aerial photographs of neighborhoods and crime statistics over time. And other studies have not taken into account, as we did, families self-selecting their locations - for example families who value exercise may be more likely to live near a park," said Dr. Sandy.


'No proof' for filling baby teeth

Filling rotten baby teeth may be an unnecessary trial for children to endure, experts say. Some 40% of five-year-olds in the UK have tooth decay and at least one in 10 of these are treated with fillings. But anecdotal evidence from 50 dentists gathered by Manchester University researchers suggests filling baby teeth may not offer significant benefits. Advisers to the NHS are now beginning a study on treatment options to provide dentists with clear guidelines.

Experts already know there is wide variation in care which means that a young child with signs of tooth decay could have no treatment, a filling or the tooth pulled out depending on which dentist they attend. Without any clear guidelines, dentists currently have to rely on their experience and judgement to decide whether or not to intervene. If the child is in severe pain and having sleepless nights, and the parent is confident that their child will cope with and benefit from the treatment, then the choice may be clear.

But when the decay is not causing symptoms, it can be difficult to decide what is in the child's best interests given that their tooth will ultimately fall out by the time they are 11 anyway. Indeed, anecdotal evidence gathered from the case notes of 50 dentists suggests filling baby teeth may achieve nothing but expose children to the discomfort of an injection and the sound of the drill.

Professor Martin Tickle, of the University of Manchester, found no difference in the numbers of extractions for pain or infection whether baby teeth had been filled or not. And when he surveyed the parents of all five-year-olds living in Ellesmere Port and Chester in 2003, he found only 6% would want their child to have a filling if they had symptomless decay in a baby tooth. In comparison, a third would want the dentist to monitor the tooth but provide no treatment.

Experts working for the Health Technology Assessment Programme plan to recruit over 1,000 children from across the UK to take part a study that will compare the outcomes of three treatment options. They are conventional drilling and filling, no fillings or a painless paint-on tooth treatment that merely seals and contains the decay.

Lead investigator Dr Gail Topping, of the University of Dundee, said: "This is a really big question to answer. "At the moment there is no clear winner and we do not know which is best to recommend. There is no guidance or mandate. "At the moment, dentists are doing what they believe is the right option for the child on a case by case basis." She said dentists would welcome evidence-based guidelines because the treatment decision can be a difficult one to make.

Kamini Shah, dentist and honorary secretary of the British Association for the Study of Community Dentistry, said: "There are two schools of thought, one being that baby teeth can cause pain and sleepless nights and so dentists should fill. "The other is that actually the evidence around filling baby teeth is questionable. "Sometimes you need to adopt a pragmatic approach rather than go in with all guns blazing. "If a child is very uncooperative but has a mouthful of non-symptomatic holes you might decide to apply a fluoride varnish to stabilise the disease rather than to do conventional fillings." Painted on with a small brush, the banana-flavoured varnish is totally painless and can slow or even stop the decay if applied often enough.

Dr Shah said: "That way you gain the child's confidence and can work on prevention. You do not want to upset the child and make them phobic of future treatments. "The problem arises when children come in aged three or four and it is their first experience of the dentist and it is because they are in pain. "In that scenario you can well imagine that they might not be most cooperative."

She said in extreme cases, and when the decay was so bad it necessitated treatment, a child might be referred for anxiety management or have the teeth removed under general anaesthetic.

Recently, an eight-year-old girl starved to death because of an apparently severe dental phobia. Sophie Waller, from St Dennis in Cornwall, is thought to have been so traumatised by her phobia that she refused to open her mouth after having eight teeth removed under general anaesthetic.

The full trial will run for four years from 2011 across England, Scotland and Wales, with a feasibility study starting in the coming months.


No comments: