Download Starchy foods may put children at risk of fatty livers

Starchy foods may put children at risk of fatty livers
Seeing It In 5-Year-Olds
Sharon Kirkey, CanWest News Service
Published: National Post, Monday, September 24, 2007
A generation of children is at risk of fatty liver disease because they eat too many starchy
foods, new research suggests.
Rapidly digested carbohydrates found in foods from white bread and potatoes to instant
oatmeal cause fat to accumulate in the liver, Boston researchers have found. It is these
same types of foods that are force-fed to geese in order to make foie gras.
If confirmed in humans, the mouse study suggests fast-burning carbs could be driving
what is rapidly becoming a major public health worry, says Dr. David Ludwig, director
of the Optimal Weight for Life program at Children's Hospital Boston, and lead author of
a study published in this month's issue of the journal Obesity.
Non-alcoholic fatty liver disease, where five per cent or more of the liver cells are gorged
with fat, is showing up in increasingly younger children.
"I do not want children to grow up with liver disease because we forgot to tell them how
to eat," says Dr. Eve Roberts, an adjunct scientist at Toronto's Hospital for Sick Children.
In 2000, Dr. Roberts reported the first child with cirrhosis of the liver caused by fatty
liver disease. That girl was 10 years old.
Dr. Ludwig is now seeing it in five-to seven-year olds. The youngest child reported with
fatty liver was two. Once unheard of in children, it now affects as many as one in three
obese kids, he says.
The condition can lead to hepatitis, fibrosis, cirrhosis and liver failure.
Rapidly digested carbohydrates, known as high-glycemic-index foods, increase blood
sugar, which triggers an outpouring of insulin by the pancreas. After the pancreas has
dealt with the blood sugar, it discharges an extra burst of insulin toward the liver. This
may cause the liver to mop up more carbohydrates and store them as fat.
Dr. Ludwig's research team fed two groups of mice identical diets except for the starch.
One group got a diet high in rapidly absorbed, high-glycemic-index carbs, the others
were fed slowly absorbed, low-glycemic-index carbs. After six months, the animals
gained the same amount of weight. But the high-glycemic group had substantially more
total body fat, meaning they had less lean tissue. They also had more fat in their blood
and about twice as much fat in the liver.
"Just raising blood sugar after a meal and the associated surge in insulin seems to be
enough to dramatically alter the course of this disease," Dr. Ludwig says.
The startling rise in fatty liver disease has been caused not just by a growing prevalence
of obesity, but also by the rising glycemic load of the North American diet, the researcher
says. Ironically, these are all the foods people turned to as they tried to remove fat from
their diets -- white bread, white rice, potato products, prepared breakfast cereals, low-fat
snacks, chips, popcorn -- "tens of thousands of primarily processed carbohydrate foods
that come in packages," Dr. Ludwig says.
Those foods can raise blood sugar and insulin levels as much as (or even more than) an
equivalent amount of table sugar. Dr. Ludwig says that overfeeding ducks and geese
high-glycemic grains makes foie gras, or "fatty liver."
Dr. Ludwig's group is now testing whether a low-glycemic index diet can reverse fatty
liver in overweight children. Such a diet includes almost all non-starchy vegetables and
fruits -- especially apples, pears, peach and berries (as opposed to tropical fruits like
bananas and melons) -- and almost all beans. Pasta, even if it's made from white flour, is
also digested slowly because it has such a tight food structure.
But Dr. Ludwig cautions because something might say "whole grain" or have oats as an
ingredient doesn't mean it has a lower glycemic index. The key is the processing of the
grain. For example, stone-ground bread is better than highly refined white bread. Oldfashioned oatmeal that's cooked slowly beats instant oatmeal, and brown rice is better
than white.