galya
Guest
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 Posted: Sat Nov 15, 2003 12:02 am Post subject: Glyoxylate Cycle in humans??? |
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The study>s results aside (not yet on Medline), the following
paragraph suggests an explanation that is OUT of what is known about
the glyoxylate cycle. Is there any literature to support such
speculation?
Thanks,
galya
<<Kokavec added that these findings also support their previously
published theory that alcohol may activate a new energy system that
was thought, until recently, to exist only in plants and other
organisms that do not require oxygen. "The glyoxylate cycle is an
energy system that can convert fat into carbohydrate," she said. "The
glyoxylate cycle does not require thiamine, utilizes acetate as an
energy source, and can be switched off by glucose.>>
Public release date: 13-Nov-2003
[ Print This Article | Close This Window ]
Contact: Anna Kokavec, Ph.D.
akokavec@planet.net.au
61-3-5261-7172 (Australia)
La Trobe University
Alcoholism: Clinical & Experimental Research
Moderate alcohol consumption after meals can decrease levels of
insulin
Insulin is a hormone that allows blood glucose to provide energy to
most of the body>s cells.
A lack of insulin can effectively cause some cells to "starve,"
leading to serious health consequences such as diabetes.
New research shows that drinking a moderate amount of white wine on
its own after a meal can cause levels of insulin to drop almost
immediately.
Insulin is a hormone that allows blood glucose to provide energy to
most of the body>s cells. New research published in the November issue
of Alcoholism: Clinical & Experimental Research shows that drinking a
moderate amount of white wine on its own after a meal can cause levels
of insulin to drop almost immediately.
"A small to moderate amount of alcohol is accepted and indeed often
recommended as beneficial to one>s cardiac health," said Anna Kokavec,
a research psychologist affiliated with La Trobe University in
Bundoora, Australia and first author of the study. "However, only a
limited number of studies have assessed the effect of consuming
readily available alcoholic products on major processes in the human
body."
Eating foods high in carbohydrates will normally increase
blood-glucose levels for several hours, which in turn, encourages
insulin production by the pancreas. Insulin enables glucose, the
body>s chief source of energy, to gain entry into most of the body>s
cells located outside of the brain. A lack of insulin can effectively
cause some cells to "starve," leading to serious health consequences
such as diabetes.
"We know that drinking alcohol can affect the body>s production of
insulin," said Kokavec. "However, researchers in the past have
obtained mixed results and it is only now becoming clear that the
effect of alcohol on insulin may depend on the presence or absence of
food. Given the discrepancy in the insulin data, the association
between food and insulin production, and the important role of insulin
in energy production and usage, we felt that the effect of drinking a
popular alcoholic beverage such as white wine on insulin production
under variable nutritional conditions warranted investigation."
Researchers examined eight non-diabetic males between the ages of 19
and 22 years. All were required to consume pizza and a soft drink for
45 minutes, and then slowly drink three standard units of white wine
(10 grams of alcohol each; 30 grams total) during a 90-minute period
following their meal. Plasma glucose and plasma insulin levels were
assessed during and following the alcohol-consumption period.
"Our results showed that drinking a moderate amount of white wine on
its own after a meal can cause the level of insulin to drop almost
immediately," said Kokavec. "This was accompanied by a similar
lowering of the blood-glucose level and, in some individuals, to a
very dangerously low level. The level of insulin after little more
than one glass of white wine was similar to the level of insulin
usually seen before a meal. When this is considered together with the
blood-glucose finding, it suggests that drinking white wine on its own
may promote a pseudo-diabetic condition, changing the way the body
produces and uses glucose. This could have serious consequences
because some of the cells in the body could be starved of energy,
which could ultimately lead to disease."
Kokavec added that these findings also support their previously
published theory that alcohol may activate a new energy system that
was thought, until recently, to exist only in plants and other
organisms that do not require oxygen.
"The glyoxylate cycle is an energy system that can convert fat into
carbohydrate," she said. "The glyoxylate cycle does not require
thiamine, utilizes acetate as an energy source, and can be switched
off by glucose. If alcohol does indeed activate the glyoxylate cycle
in the human liver, then this could offer an explanation for
alcohol-related fatty liver, thiamine deficiency, alteration in energy
metabolism under fasting conditions, and lack of appetite for
carbohydrates [that are] found in alcoholics, the reasons for which
have baffled researchers for years."
Furthermore, said Kokavec, "present results highlight the need to
strictly control for nutritional factors when designing alcohol
research as nutritional status may be a confounding factor that is
contributing to variability in the alcohol literature. In addition,
given the possibility that alcohol may activate the glyoxylate cycle,
an energy pathway that can be switched off by glucose, it may be
important for scientists to specifically control for the presence of
carbohydrates when investigating the effect of alcohol." |
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