Deutsches Zentrum fuer Diabetesforschung DZD
The global proliferation of overweight and obese people and
people with type 2 diabetes is often associated with the consumption of
saturated fats.
Scientists at the German Diabetes Center (Deutsches
Diabetes-Zentrum, DDZ) and the Helmholtz Center in Munich (HMGU) have found
that even the one-off consumption of a greater amount of palm oil reduces the
body's sensitivity to insulin and causes increased fat deposits as well as
changes in the energy metabolism of the liver.
The results of the study provide information on the earliest
changes in the metabolism of the liver that in the long term lead to fatty
liver disease in overweight persons as well as in those with type 2 diabetes.
In the current issue of the Journal of Clinical Investigation, DZD researchers working at the German Diabetes Center, in conjunction with the Helmholtz Center in Munich and colleagues from Portugal, published a scientific investigation conducted on healthy, slim men, who were given at random a flavored palm oil drink or a glass of clear water in a control experiment.
The palm oil drink contained a similar amount of saturated fat
as two cheeseburgers with bacon and a large portion of French fries or two
salami pizzas.
The scientists showed that this single high-fat meal sufficed to
reduce the insulin action, e.g. cause insulin resistance and increase the fat
content of the liver. In addition, changes in the energy balance of the liver
were proven.
The observed metabolic changes were similar to changes observed
in persons with type 2 diabetes or non-alcoholic fatty liver disease (NAFLD).
NAFLD is the most common liver disease in the industrial nations
and associated with obesity, the so-called "metabolic syndrome," and
is associated with an increased risk in developing type 2 diabetes.
Furthermore, NAFLD in advanced stages can result in severe liver damage.
"The
surprise was that a single dosage of palm oil has such a rapid and direct
impact on the liver of a healthy person and that the amount of fat administered
already triggered insulin resistance," explained Prof. Dr. Michael Roden,
scientist, Managing Director and Chairman at the DDZ and the German Center for
Diabetes Research (Deutsches Zentrum für Diabetesforschung, DZD).
"A special feature of our study is that we monitored the
liver metabolism of people with a predominantly non-invasive technology, e.g.
by magnetic resonance spectroscopy. This allows us to track the storage of
sugar and fat as well as the energy metabolism of the mitochondria (power
plants of the cell)."
Thanks to the new methods of investigation, the scientists were
able to verify that the intake of palm oil affects the metabolic activity of
muscles, liver and fatty tissue.
The induced insulin resistance leads to an increased new
formation of sugar in the liver with a concomitant decreased sugar absorption
in the skeletal muscles -- a mechanism that makes the glucose level rise in
persons afflicted with type 2 diabetes and its pre-stages.
In addition, the insulin resistance of the fatty tissue causes an
increased release of fats into the blood stream, which in turn continues to
foster the insulin resistance.
The increased availability of fat leads to an increased workload
for the mitochondria, which can in the long term overtax these cellular power
plants and contribute to the emergence of a liver disease.
