Dear Lactnetters, So good to be on line once again!!
My eyes caught the post about chylothorax and your questions about the fat
in mothers milk.  There is actually a simple explanation I think.

First you have to remember that there are 2 different types of fat: long
and medium chain triglycerides (LCT and MCT).
Next you need to keep in mind that the 2 types of fat are absorbed via 2
different pathways:
        -  Long chain: enter the bowel mucosa then are "emulsified" and go
to the lymphatic vessels (best described as slits in tissue where clear
fluid circulates).  In simple the fluid not picked up by vein goes back
that way along with stuff like LCT.

        - Medium chain: go straight through the bowel into the portal
circulation and the inferior vena cava via the liver without going through
the lymphatics.

OK ?  are you guys following so far??

Now that you have the normal stuff down you also need to know that the
lymphatics have a system of their own and converge together kind of like
veins to end up in the "thoracic duct" with goes directly into the heart.

People who have a chylothorax have chyle (or lymph) in the chest cavity
around the lungs.  It can be occuring after an operation such as heart
surgery which severed lymphatic ducts in the chest. Or because of high
pressure in parts of the heart making it difficult for the chyle to drain
in the heart.  Or because of congenital malformations.

Ok?  now what does this have to do with the type of fat you eat?
Well, very simple.... When you eat the LCTs you have to use the
lymphatics, right?  yeap !  so that increases the flow through
thelymphatics and if there is a problem somewhere such as a leak, it's
going to make it worse and the chest is going to fill with more chyle.

MCT is commercially available either by itself or within formulas.
(Portagen has about 90% and Pregestimil about 50% of fat as MCT).  Plus,
stuff like chylothorax usually fixes itself with time if you can decrease
the pressure in the lymphatics and consuming MCT instead of LCT is one way
to do that.  So it makes sense to me to want to feed this baby MCT rather
than LCT.  To keep this baby breastfeeding, the only way I would do it is
to skim mom's milk which is made mostly of LCT and replace the fat with
MCT and give the new mixture to the baby.  One would leave a little LCT
either in each feed or by letting the baby take regular milk about 10% of
the time to give the baby the essential fatty acids not provided by MCT.


Hope this all makes sense to  you all and will help you understand what
they meant by mom's milk was "too rich".. Not exactly, just the wrong type
of fat for the present condition.

By the way, I still follow lactnet pretty closely but limit my responses
to gi interests.  I love the new system, Kathy and Kathy because I can
look at 1 post without scrolling through the whole thing.  If you have
messages for which you would like the imput of a pedi gastroenterologist
who knows a little about breastfeeding, make sure you make it clear in the
subject!!!!

Good talking to you all

Maryelle,
You faithful pedigi who's daughters are now 5.5years and 14 month and
still both nursing strong!!!!