New research suggests that the ubiquitous sugar known as fructose may cause certain fat cells in children to multiply faster, which might play a key role in childhood and adult obesity.
Fructose is a component of high-fructose corn syrup, which is widely used in a variety of foods, including soft drinks, candy and many processed foods.
But although the new studies did use cells taken from children, they were performed only in test tubes and experts called for caution in interpreting the findings.
"You can't draw a conclusion based on a single study, and this study was not done in humans [only human cells]. We need to take that into consideration," said Keri Gans, a spokeswoman for the American Dietetic Association.
Obesity a growing problem
That said, childhood (and adult) obesity is a legitimate and growing concern around the world. This condition ups the risk for heart disease, type 2 diabetes and a host of other diseases. Some of this is already being played out among young people.
"We're seeing more type 2 diabetes in children, and that's due to children being overweight," Gans said. "What's even scarier is that children are increasing their risk for developing heart disease earlier."
Experts have noted a rise in blood pressure and cholesterol levels in overweight children.
"The fear is that this generation might be the first generation that might not outlive their parents," Gans said.
According to the research, high-fructose corn syrup is becoming more prevalent in American foods than sucrose.
The authors, led by doctoral candidate Georgina Coade at the University of Bristol in Britain, extracted pre-adipocytes - the cells that eventually turn into fat cells - from 32 children who were normal weight and were still pre-pubescent.
The cells were both subcutaneous fat cells (those just below the skin) and visceral cells (those deeper in the abdomen).
The cells were soaked in a solution of normal level glucose, high-level glucose or in high fructose and were allowed to mature.
According to the researchers' calculations, fat cells that grew in fructose divided and multiplied more than those soaked in glucose - but this was true only for visceral fat.
On the other hand, both visceral and subcutaneous fat cells exposed to glucose displayed increased insulin resistance, a risk factor and property of diabetes.
Different types of fructose
But Dr James Rippe, a consultant for the Corn Refiners Association, founder and director of Rippe Health Evaluation and chairman of the Centre for Lifestyle Medicine at the University of Central Florida, pointed out that high-fructose corn syrup, which has been implicated in the diabetes and obesity epidemics, is not equivalent to pure fructose.
"It's a very unfortunate and common error. They're not the same thing," he said. "High fructose corn syrup is half fructose and half glucose."
Still, Gans said, "the main message is we're talking about sugar, and the bottom line is too much sugar of any kind is going to give you too many calories, and too many calories lead to weight gain, and that's where the problem lies."
Dr Neslihan Gungor, an associate professor of pediatrics at Texas A&M Health Science Centre College of Medicine and a paediatric endocrinologist at Scott & White Hospital in Temple, Texas, reiterated the importance of remembering that the findings came only from laboratory study.
"We still must see whether or not the findings are observed in the human body," she said. "It wouldn't be fair to take these results and apply them to the whole human organism." - (Amanda Gardner/HealthDay News, June 2010)
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