|
|
[Article based on a reply to a question on the SAH-AP email list. I am not a medical professional but have tried to put into plain English what I have learnt, as a person with allergies and mother of allergic children.]
The theory of delaying solids is basically because in a younger baby, the gut is more porous, so proteins (which are the components of food that actually cause allergies) leak into the bloodstream. These protein molecules are picked up by the baby's immune system and react as if the food protein was a germ. Henceforth, whenever the baby eats that particular food, his body is already primed and ready to "attack" it - the immune system reacts as if that food is an infection. This is what we call an "allergic reaction". "Growing Out" of Food Allergies?As a baby grows older, the gut becomes a more efficient filter and therefore the proteins don't "leak" into the bloodstream so easily. Instead of leaking through, the proteins are broken down by the enzymes in the gut and denatured. Then they are no longer recognisable to the baby's immune system and cannot be mistaken for germs any more. This is why baby's usually "grow out" of food allergies. Delaying the introduction of solids allows the gut to mature so that this leaking doesn't occur so much, and therefore the protein never gets into the blood stream to trigger an allergic reaction. Secondly, delaying the introduction of solids allows a baby's immune system to mature so that it is better at detecting the difference between a food protein and a genuine germ. Even though I said that most babies grow out of food allergies due to the "leaking gut" effect decreasing, once the baby's immune system is triggered to a food protein, mistaking it for a germ, that baby's immune system will always be less efficient. The immune system will continue to make mistakes, so that even though food proteins are no longer getting into the bloodstream to cause allergic reactions, pollen or house dust in the lungs or nose, or soap on the skin will also be mistaken for germs and cause nasal allergies, asthma or eczema ie what starts out as food allergies becomes allergic dermititis/eczema and asthma in reaction to enviromental allergies. At least that is the theory. The earlier an allergy is triggered, the worse this effect tends to be - that one bottle of formula given in the hospital nursery could have devastating effects because it could trigger an allergy in a baby at the most vulnerable time of it's life (which is what happened to me as a baby). I read time and time again of women annoyed because their baby was given a bottle of formula in the nursery - I wouldn't be annoyed if this happened to me, I would be homicidal! In fact, my last birthplan stated that if this happened to me, and my baby subsequently suffered food allergies, I would sue! Lifelong Allergies?Interestingly enough, I have read that allergies that come to a breastfed baby via the breastmilk (such as dairy proteins in the mothers diet that cause colic in the baby) don't seem to cause a lifelong allergy in most cases (peanuts being a possible exception to this). This is thought to be caused by the damping-down effect of the other immune- system factors in the breastmilk. It is thought that breastmilk can "train" the baby's immune system to better distinguish genuine germs from other proteins. I mentioned peanuts as an exception. This is probably due to the fact that peanut proteins are particularly tiny and can leak through the gut exceptionally easily, and also get into breastmilk very easily; also, some peanut proteins are very, very similar to human proteins and are particularly obvious to the immune system, thus causing a major reaction. If you want to read up on this subject, I can recommend books by Maureen Minchin, who is an Australian Lactation Consultant and expert on allergies. One of her theories is that if three successive generations breastfeed exclusively for 6 months and are careful in introducing solids, then allergies may disappear from that family. It may also work in reverse - that the more generations formula feed, introduce allergenic solids early etc., the worse allergies will become. This might explain a figure I came across of 60% of children attending a clinic for severe food allergies were not from allergic families. Makes you think, eh? For further suggestions on introducing solids to avoid allergies, please see my schedule Avoiding Allergies When Weaning Breastfeeding Links
Compiled by Anna
Hayward (c) 1997. |
There
is research to show that avoiding/delaying the introduction of
foods to a baby until the second half of the first year of life
does reduce the incidence and/or severity of allergies in the
child, not just food allergies, but other allergies such as asthma
or eczema. The allergies tend to appear later, be more mild and
children tend to grow out of them earlier. So even if you don't
totally avoid allergies, you have probably made them significantly
milder than they would have been.