Hi Robyn,
 
 
>I have several questions, trying to figure out for myself why
>people may be reacting to various foods, including dairy, and
>if any of my reactions are due to dairy or not.
 
 
I may be able to help with some of your questions.
 
 
>
>1. I have heard that there are basically 3 things people may be
>reacting to in dairies: lactose, casein, whey. Some people
>may be sensitive to some, but not others. E.g. sensitive to
>casein, but not whey. Is this true?
 
I can't give you a complete answer here. I can tell you that to digest
lactose, the sugar in milk, you need intestinal enzymes called "lactaze".
These enzymes will cleave the lactose molecules in such a way that they can
then be safely absorbed into the blood stream.
 
In casein intolerance, your intestine has most likely allowed molecules of
casein into the blood. As these are proteins, the immune system mounts a
response against them, and any further invasions are met with a vigorous
response.
 
>
>2. If the reaction is to proteins - casein, whey - can one take
>protein digesting enzymes to break them up?
 
Because proteins are composed of strings of amino acids, and because the
enzymes only cleave the proteins into several peptide chains (groups of
amino acids strung together) it is still likely that your immune system will
recognize the peptide sequences.
 
 
 I am already taking
>bromelain, there are plenty others out there as well. Or is the
>reaction to specific chains of aminos that are found in milk
>proteins and would not be broken down by these enzymes.
 
The peptide chains would retain the recognizable sequences. There is quite a
lot of evidence that only a tiny sequence is enough to trigger an immune
response.
 
>
>3. If the reaction is to casein (or even whey) why is there
>reaction to other dairies, such as yogurt. I thought that
>bacteria in yogurt use the milk proteins to make the proteins
>they need, therefore the only milk proteins found in yogurt
>would be 'residual' proteins, not yet digested by the bacteria.
>Is this residual amount of milk proteins responsible for the
>reactions?
 
Perhaps, but even if all milk proteins were eliminated the above would
likely still apply.
 
 
>
>4.a. Is it possible that reaction to milk proteins really happens
>due to other reasons. For example, gluten, yeast overgrowth,
>or other problems causing 'leaky gut syndrome' or similar
>problems. So your body now starts absorbing incompletely digested
>milk proteins and then starts developing antibodies to them.
>Has anybody had these kinds of problems? And if yes, has milk
>intolerance improved when those problems were taken care of?
 
This is the dynamic that some researchers are now considering as possible in
the development of autoimmune diseases, and some malignancies.
 
>
>4.b. The reason I am thinking of this is that if the body is
>developing antibodies to milk proteins they must be getting into
>blood steam. The body does not normally develop antibodies to
>things still in the gut, as that will be broken down and there
>is no reason to 'waste' immune system efforts on it. If milk
>particles (proteins, lactose, whatever) are getting into blood
>stream then the problem is with the 'leaky gut'. Does this make
>sense?
 
It makes perfect sense to me. :=)
 
 
 
>
>5. Could the problems with milk (and eggs, etc. for that matter)
>be due to hormones, antibiotics, pesticides, etc that go into
>cows and end up in milk? Anybody switched to organic dairies
>(or eggs, etc.) and found their symptoms improve?
 
We know that NSAIDs, gluten, and other protein intolerances, bacterial
overgrowth, and perhaps yeast infections, can all cause intestinal
permeability. It seems a reasonable possibility that the chemicals and
hormones you mention may also cause the permeability.
 
 
 
>
>6. I have seen a lot of references to paleolythic diets, eating
>only what could be picked in nature/killed with a stick. Dairies
>are usually excluded from that list on the basis that neanderthals
>did not raise cows. But they were still breast fed as infants.
 
Cow's milk is very different from human milk. There is much less sugar
(brain food) in cow's milk, and much more casein. If we want to grow large,
slow-witted cattle, then cow's milk is the answer. I don't think those are
qualities we are trying to perpetuate in the human race.
 
 
>Does anyone know why these diets exclude milk if it's a natural
>part of one's life early on? How is human milk different from
>cows, goats, etc.?
 
My memory is vague on goat's milk, but you would still need the lactaze to
tolerate it.
 
>
>7. I remember seing that casein is similar to another protein
>in another food that people are sensitive to, but can't remember
>which one. Is that gluten? Anybody out there remembers this?
 
It is similar in the sense that the pepsin digests of both proteins can
result in psychoactive peptides with opioid activities.
 
You might have a look at Don Wiss' homepage. He has links to a milk free
page, and to a page of Dr. Reichelt's writing. That would give you much
better information than I can, if you have access to that kind of thing.
 
 
http://www.panix.com/~donwiss
 
I hope that is helpful.
 
Best Wishes,
Ron Hoggan   Calgary, Alberta, Canada