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[Supertraining] Eating to Keep Diabetes in Check carruthersjam Fri Jul 11 18:26:48 2008

The below may be of interest:

Eating to Keep Diabetes in Check

http://health.nytimes.com/ref/health/healthguide/esn-diabetesdiet-
ess.html

*One in four people born today are expected to develop Type 2
diabetes during their lifetimes.

*Shedding excess weight and exercising more can cut Type 2 diabetes
risk by 58 percent.

*Favoring foods in their unrefined state -- brown rice and whole
grains, for instance -- can help keep blood sugar levels from spiking.

*Exercise improves blood sugar control by increasing insulin
sensitivity.

As rates of Type 2 diabetes continue to rise around the world,
experts say we mostly have ourselves to blame. Genes certainly play a
role in determining risk. But the surge of new cases of this
debilitating disease is caused mostly by poor diets and lack of
physical activity.

By all rights, the prescription should be simple: lose weight if you
are overweight, and get more exercise.

Easy? Of course not. Experts have yet to come up with anything close
to a surefire approach to help people shed pounds. And dietary
recommendations to prevent or slow diabetes have often been
contradictory and confusing. Nearly 30 years after the American
Diabetes Association recommended a low-fat, high-carbohydrate diet to
control diabetes, overturning the high-fat, low-carbohydrate approach
of earlier decades, controversy still swirls around the amount and
types of carbohydrates to eat.

Much of the debate focuses on the glycemic index, a measure of how
carbohydrate-rich foods affect blood sugar, and whether these effects
play a significant role in the progression of Type 2 diabetes. Foods
high on the glycemic index, like sugared beverages, cake and white
rice, are known to send blood sugar levels up sharply after a meal.
Foods low on the index, like broccoli, lettuce, brown rice and whole
grains, on the other hand, take longer to digest and hence keep blood
sugar levels on a more even keel.

The American Diabetes Association has decided that patients should
not be counseled to take the glycemic index into account when
choosing foods. "Although it is clear that carbohydrates do have
differing glycemic responses," its policy statement declares, "the
data reveal no clear trend in outcome benefits."

That's a mistake, says Dr. David Ludwig, an endocrinologist at
Children's Hospital in Boston and an associate professor at Harvard
Medical School. "High-glycemic foods like refined grains raise blood
sugar levels two to three times higher than unprocessed foods with a
low glycemic index," he said. When blood sugar levels spike, the body
must churn out insulin to move glucose out of the bloodstream and
into cells, where it is used for energy.

"If you're eating high-glycemic foods meal after meal, snack after
snack, day after day, that's going to put a lot of stress on the
system that produces insulin," Dr. Ludwig said. "If the system is
already compromised due to a family history of diabetes, those rapid
swings of blood sugar could make a difference between remaining
healthy or decompensating into Type 2 diabetes."

Dr. Ludwig cites a study he conducted in which rats fed foods high on
the glycemic index lost lean muscle mass, gained body fat and began
to lose their ability to control blood sugar.

"A high percentage of insulin-producing cells in the high-glycemic
rats were undergoing a process of destruction, disruptions in their
architecture and scarring," Dr. Ludwig said. The same thing, he
suspects, happens in people.

But so far, evidence from human studies has been sketchy. In one
recent Canadian study, there were no differences in blood sugar
control among 162 volunteers assigned to one of three very different
diets for a year: a low-carbohydrate regimen; a high-carbohydrate,
low-glycemic-index diet; or foods high on the glycemic scale. Fasting
glucose, a test widely used to monitor diabetes risk, actually rose
in the group eating the low-glycemic foods.

A second study of 1,898 people found that risk of Type 2 diabetes was
the same whether people reported eating foods high or low on the
glycemic index.

"The notion that glycemic index matters makes intuitive sense," said
Dr. John M. Miles, a diabetes expert at the Mayo Clinic. "A lot of
people have strong feelings on the subject. But the evidence just
isn't there."

Dr. Xavier Pi-Sunyer, an endocrinologist and diabetes expert at St
Luke's-Roosevelt Hospital in New York, agreed. Given the new
findings, "It seems unwise at this point to burden Type 2 diabetes
patients with trying to pick and choose among different high- and low-
glycemic-index foods," he wrote in a recent review of the evidence.

But Dr. Thomas Wolever, a University of Toronto researcher who led
the Canadian trial, noted that those who ate low-glycemic-index foods
showed improvements in blood sugar control after meals, which may be
a more important measure of glucose control than the fasting glucose
test. They also had reductions in levels of C-reactive protein, a
marker for inflammation that also appears to be linked to diabetes
risk.

Low-glycemic diets may have another crucial advantage, Dr. Wolever
suggested: they help some people shed pounds. "I've had people tell
me it's the only way they've been able to lose weight," he said.

While no single diet works for everyone, losing weight may be the
single most effective way to lower Type 2 diabetes risk. Evidence for
that comes from a major trial sponsored by the National Institutes of
Health, in which a randomly assigned group of overweight volunteers
with early signs of diabetes were encouraged to lose about 7 percent
of their body weight and engage in 150 minutes of moderate exercise
weekly.

Over the next three years, only 5 percent of the lifestyle
intervention group went on to develop diabetes each year, compared
with 11 percent of volunteers in a control group. Weight loss and
exercise proved more effective than a leading diabetes medication in
preventing Type 2 diabetes.

"There's no question that if we can get people to lose 5 or 10
pounds, we'll be doing them a world of good," Dr. Wolever said. The
confounding question remains how.

================
Jamie Carruthers
Wakefield, UK