Nutrition experts blame sugar as a major cause of the rise in obesity in the United States, noting that the rise in overweight children is especially alarming. Some scientists have zeroed in on fructose as a major cause, especially high-fructose corn syrup that is used in soft drinks and processed foods. Manufacturers have staunchly defended their product, saying it is no more a cause of obesity than other foods. New research may prove their critics were right.
A study at the United Kingdom's University of Bristol found that when a child's fat cells mature, if fructose is present, more of the cells mature into fat cells in belly fat. In addition, the cells are less able to respond to insulin in both belly fat and in subcutaneous fat located below the skin.
“Our results suggest that high levels of fructose, which may result from eating a diet high in fructose, throughout childhood may lead to an increase in visceral [abdominal] obesity, which is associated with increased cardiometabolic risk,” lead author Georgina Coade said in a statement. Abdominal obesity, which is defined by a large waistline, raises the risk of cardiovascular disease and Type 2 diabetes.
Early studies had shown that fructose had a negative effect on fat distribution in rats, but people hadn't been studied. Coade studied biopsy specimens from 32 healthy children who had not undergone puberty.
The investigators obtained preadipocytes — the precursors to fat cells that have the potential to differentiate, or mature, into fat-containing adipocytes — from the biopsies. They then allowed the precursor cells to mature for 14 days in a culture media containing one of three substances: normal glucose (the main sugar found in the bloodstream and the principal source of energy in the body), high glucose, or high fructose.
The researchers found that fructose produced different effects than those of glucose and caused the fat cells to differentiate more — that is, to form more mature fat cells — but only in visceral fat. The fructose also decreased the ability of cells to take up glucose from the bloodstream into fat and muscles. Decreased sensitivity to insulin is a characteristic of Type 2 diabetes.
“Fructose alters the behavior of human fat cells if it is present as the fat cells mature," Coade said.
According to data from the National Health and Nutrition Examination Survey, two-thirds of Americans are overweight or obese. Government statistics show that Mississippi has the highest percentage of obese and overweight children — 44.4 percent.
According to HealthyAmericans.org, obesity costs the United States $75 billion each year in direct costs, but the total costs could reach $139 billion.
© 2010 Newsmax. All rights reserved.
