[2 emails combined.  BIG]
From Gary Holowicki:
>In medicine the principle translates to advise to people to eat complex
>carbohydrates rather than refined sugars if you have hypoglycemia.
 
Gary,
 
Thank you for the responding to me privately; however, I thought this was
a good discussion for the FML.  I understood what you were saying in your
original posting [2 Sep 1998 to 3 Sep 1998 (#1998-2420)], so the interesting
analogy was probably unnecessary.  As I originally stated in my question to
you on the FML, "I was wondering if you could be more specific about honey
not causing the insulin spike that kayro or other refined sugars causes.  I
wasn't aware that there was much of a difference, could you point me in the
direction of your data." I guess the operative word here is data, not
analogy.
 
In fact, since it had been a little while since my nutrition class and GI
physiology, I thought that I should do a little of my own research on this
topic.  If anyone sees me making a mistake, please point it out as these
are not my best subjects.
 
First of all, as you were prescribing Timmy's Tonic "in water" for a ferret
with insulinoma, the dose of honey is probably not that large.  However, I
would be concerned about the ingestion of any honey for this animal.  In
fact, in Ferrets, Rabbits, and Rodents (Hillyer and Quesenberry, 1997, p.
89), it is recommended that "unless ferrets show signs of hypoglycemia,
instruct owners NOT to give simple sugars such as honey or corn syrup
because these foods can stimulate insulin secretion, precipitating a
hypoglycemic episode soon after."
 
Furthermore, I question the accuracy of your statements about honey vs.
"karo or other refined sugars."  It turns out that honey is mostly made up
of fructose (a monosaccharide, ie. simple sugar), whereas "refined sugars"
(do you mean a table sugar like sucrose?) can mean anything that is
purified (eg. sucrose, fructose, etc.).  If by "refined sugars" you mean
sucrose (a disaccharide), then your "refined sugar" is actually a more
complex sugar than fructose.  In addition, one of Karo syrup's major
ingredients is high fructose corn syrup (ran out to the grocery store to
check).  So in fact, this "refined sugar" is fructose (a simple sugar) and
there should be little or no difference in the absorption of the type of
sugar with karo syrup vs. honey because they are both fructose.  If there
is a difference, it may come with the concentration of sugar or the medium
(ie. what else is in the solution - fats, proteins, etc.) with which the
sugar is ingested.  Either way, I don't have any specific data (other than
what I can infer from F, R, & R (H & Q) and what I have stated above.  In
addition, I am still not sure what you meant in your original posting or
where you got your "data".
 
Now, back to fructose vs. "refined sugar" sucrose (simplified).  It turns
out that fructose and sucrose are both absorbed in the small intestine when
enzymes located in the membranes of the enterocytes (one of the cells that
line the lumen of the intestine) that form the microvilli brush border
(cool descriptive name, huh?) digest them.  Sucrose is broken down by an
enzyme called sucrase into a molecule of glucose and a molecule of fructose
(there is that pesky fructose again).  Now this is where it gets
interesting.  Glucose is actively absorbed into the cell and then diffuses
into the portal blood.  Fructose, in contrast, is absorbed by facilitated
diffusion and then much (not all) of it is converted to glucose by the
enzyme sucrase and then absorbed into the bloodstream.  Because fructose is
not actively absorbed like glucose, it is actually absorbed at about one
half of the rate of glucose.
 
To summarize, we have fructose which is absorbed directly, but then
converted to glucose vs, sucrose which is digested into fructose (see above)
and glucose which is absorbed very rapidly.  So, from this information, it
isn't really clear which glucose (from sucrose or fructose) gets into the
bloodstream fastest.  To complicate things even more, there is some
research presented in The Biology and Diseases of the Ferret, 2nd Edition,
(Fox, 1988, pp. 155-156), that "large amounts of sucrose may result in
measureable urinary sucrose and fructose levels" (ie.  sucrose isn't being
completely absorbed - now I really wonder if there is much of an insulin
spike) and that there is evidence that the ferret may have low intestinal
levels of sucrase and a limited ability to convert fructose to glucose.
This makes sense because the ferret, afterall, is an obligate carnivore
whose diet should be made up of mostly proteins and fats which are
digested, absorbed, and eventually converted into glucose (or glycogen) by
the process of gluconeogenesis in the liver.  So, the ferret doesn't really
need, nor should it really get sugar in its diet.
 
So, since these all of these sugars (as well as proteins and fats) are
mostly converted into glucose and glucose is the "fuel" on which the body
"runs", it is glucose to which the body reacts.  The method by which the
body reacts and secretes insulin doesn't appear necessary to this
discussion based on the previous information, so I will leave it out.
 
Do you have some information that I am leaving out or could you point me to
a reference that would help me understand what you meant?  Thanks.
 
******************************
Sean D. Sawyer V'00
SCAVMA Treasurer
University of Pennsylvania
School of Veterinary Medicine
 
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******************************
[Posted in FML issue 2422]