Allergies

About (not) consuming fresh raw fish and fresh raw egg yolks
panacea
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Allergies

Postby panacea » Tue 22 Feb 2011 07:01

http://foodallergies.about.com/od/fooda ... ght_fa.htm

Among the big 8 allergies, there is fish and eggs.

This is odd because supposedly fish & eggs are healthy for us (raw).
So why are so many people allergic to proteins in these foods?
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RRM
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Re: Allergies

Postby RRM » Tue 22 Feb 2011 10:26

There are a lot of different theories about this.
One theory is that we 'are locked up' in our houses nowadays, overexposed to dust and mites,
which may derail our immune system when we are young.
Another theory is that we are underexposed to bacteria in raw foods, with the same effects.
Yet another theory says that allergies are just part of evolutionary tactics, and that they are on the rise
because due to modern health care people survive such allergies, and reproduce.
etc etc
Also, an allergy may not be a real allergy, or a conditional one.
We had many people on this forum supposedly allergic to eggs, who appeared not to be allergic to raw egg yolk.
In general, people allergic to eggs respond immunologically to the albumin and ovomucoid in egg whites.
Ovomucoid is also an antinutrient, as is avidin, also present in egg whites.
Ovomucoid is relatively protected against heat-induced naturation, but not so much resistant to enzymatic degradation.
Ovalbumin is relatively protected against enzymatic degradation Martos G, but not when cooked.Takagi K
People allergic to fish may actually be allergic for specific amines, which may also be conditional.
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Re: Allergies

Postby RRM » Tue 24 Feb 2015 12:20

In healthy adults, about 2% of undigested dietary protein is absorbed from the intestinal tract.Husby S et al Exposure to dietary antigens may, or may not potentiate immune responses. Full Free Text In (90% of Husby S et al) healthy adults undegraded dietary antigens are absorbed after a meal, and circulate regularly in minute amounts as native protein and as immune complexes. This includes large proteins such as ovalbumin from egg whites Husby S et al. Ovalbumin is made up of 385 amino acids.

The uptake route strongly influences immune responsiveness (allergic reaction, or not). In non-sensitized individuals there is systemic immunological tolerance (“oral tolerance”), as opposed to sensitized individuals, such as with celiac disease or food allergies.Full Free Text Food allergens must cross the intestinal epithelial barrier before they can activate cells that trigger an allergic reaction. Alternatively, they may be absorbed by chylomicrons, bypassing allergic effector cells (basophils) and avoiding T-cells.
Heating reduces epithelial transport and triggering of reactions (immune responses; the sensitizing effect). Due to extensive heating, more ovalbumin is fragmentized (into peptides) by digestive enzymes, but there is no appreciable decrease in binding to immunoglobulins, and yet it does not trigger allergic reactions in the majority (55% Urisu A et al, 68% Lemon-Mulé H et al) of egg-allergic people. Heating of ovalbumin prevents its transport across intestinal epithelial cells in a form capable of triggering basophil activation or T cell activation.Full Free Text
Food-specific antibodies in circulation are commonly found despite a state of clinical tolerance to that particular food.Husby S et al

Uptake of proteins from egg whites (and peanuts and milk) is increased by the presence of long-chain triglycerides (in those foods), as they promote intestinal uptake transport by chylomicrons.Full Free Text
Another factor that strongly influences whether proteins evoke an allergic reaction, is whether the eggs are heated in combination with other ingredients, such as wheat (or soy), resulting in insoluble aggregates Full Free Text, slowing down its degradation.

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