过敏是一种免疫反应改变状态。当你的免疫系统过度对通常无害的过敏原反应时，过敏就会发作。你的身体释放出许多化学物质，其中一种叫做组胺。组胺是最丰富释放的化学物质，它可以引起过敏症状。有很多原因可以引起过敏，某些人的体质和代谢能力跟是否易产生过敏及其相关。一个人过敏有遗传倾向，而不是特定的过敏。 因此，对遗传的外来物质过敏是一种趋势。 过敏性疾病有很多原因，导致医治困惑。由于没有单一的原因，过敏症状往往被忽视，或归因于精神或情绪压力。

免疫系统是炎症开始的地方。只要被称为抗原的有害物质进入你的身体，你的免疫系统就会采取行动。一些常见的抗原是病毒，寄生虫和细菌。每一种抗原都有相对应的一种抗体或免疫球蛋白。有五种类型的抗体：lgA，lgE，lgG，lgM，lgD，而与过敏有紧密相关的三个重要抗体是：

•免疫球蛋白A（IgA）是覆盖粘膜内层的免疫蛋白，包括消化道，鼻窦，眼泪，肠液，母乳和呼吸道。他们沐浴身体表面并防止病原体进入。
•免疫球蛋白G（IgG）是血浆中免疫蛋白的主要和最丰富的抗体。他们可以穿过胎盘。
•免疫球蛋白E（IgE）是过敏反应的主要反应者，并且参与对寄生虫的反应。

有两种常见的过敏类型：空气传播过敏和食物过敏。空气过敏是指当一种不熟悉的物质，如花粉，灰尘和霉菌，首次进入人体时，身体开始制造一种特别的物质叫抗体lgE。这些lgE抗体将在下一次遇到过敏原物质时准备采取行动制造过敏反应。同时，lgE抗体将自己附属于免疫系统的肥大细胞之上，使每个肥大细胞都涂有数十万个IgE抗体。当过敏原再次进入人体并暴露于这些涂有IgE的肥大细胞时，发生过敏反应释放炎性物质并引发一系列过敏症状，如眼睛流涕，流鼻涕，鼻窦充血和疼痛，瘙痒皮疹，气喘。

摄取食物过敏原时不会产生IgE抗体，但会产生分泌型IgA的自由浮动抗体释放到消化道中。 lgA将侵入食物的颗粒从胃中进入小肠。当食物过敏原和分泌型IgA抗体结合时，它会刺激肠粘膜内层，分泌出厚厚的保护性粘液涂层。然后，由于过敏食物与对其特异的肥大细胞抗体发生化学反应，一种强力化学物质突然释放，便产生过敏反应。食物过敏在身体中遵循不同的途径，并使用与空气反应不同的化学物质。

然而，食物过敏原反应比环境空气反应更阴险。鉴于空气反应是相当局部的，即眼睛，鼻子，鼻窦，空气通道，而食物过敏反应具有更厉害的后果。例如，释放的炎性前列腺素会导致胃分泌更少的胃酸。胃酸可以刺激胃蛋白酶原的产生，胃蛋白酶原是一种蛋白质消化酶。没有足够的胃蛋白酶原，蛋白质不能正常消化。若减少了胃酸的产生，也导致食物缺少胃酸混合就进入了小肠。如果没有足够的胃酸，胰腺不能产生足够的碳酸氢盐来碱化食物，因为它依赖于胃酸来刺激才能产生足够量。碳酸氢盐较少时，胰腺也不会被刺激产生并释放必需的消化酶以完成消化。由于食物未碱化，原来的低酸性食物现在在小肠中保持相对过酸状态，小肠不能正常的完成消化，吸收和同化过程，人也就得不应有的营养， 导致免疫力下降。

健康的肠道不仅仅是消化食物，它是一种免疫屏障，可以保护身体免受外来侵略者的侵害。一个健康的肠道内壁只允许正常消化的脂肪，蛋白质和淀粉通过，以便它们可以同化。同时它也提供了阻挡不需要的消化分子，细菌产物和其他外来物质的障碍。在肠细胞之间通常是紧密配合的连接点，其不允许大分子通过。然而，当这个区域变得受刺激敏感或发炎时，细胞之间的这些连接变松动，并允许更大的分子通过。免疫系统将这些大分子解释为外来入侵者，这刺激了抗体反应。一些可能穿过受损的肠内膜的物质是细菌和真菌，有毒分子包括由消化过程产生的有毒分子和未消化的食物颗粒，这些可能直接通过弱化的连接点进入血液流动全身。

随着年龄的增长，过敏反应似乎会增加。人老了，由于免疫系统的衰弱，器官退化分阶段，以及有毒物质的累积，毒素往往会随着人的年龄增长而增加。因为随着时间的推移，人的饮食习惯不同，毒素会逐渐累积越多。

情绪紧张的情况会导致免疫系统功能下降。身体压力会增加营养需求，若不及时补充营养，会导致营养缺乏，营养素缺乏进一步伤害免疫系统。不良饮食会影响人体对抗疾病的能力，它使身体不受保护。由于一个器官或身体系统受到压力，失去了动态平衡，只要有一个器官或系统不能正常发挥其功能，它会影响其他器官和系统的功能。这些其它器官和系统必将做更多的工作来补偿那些受到压力的器官和系统。随着营养不良的继续，这些器官和系统变得紧张，失去了发挥最佳功能的能力。身体只要有一处受损，它不可能不影响身体的其它部分。

Allergy is a state of altered immune reactivity. Allergies kick in when your immune system overreacts to normally harmless substances called allergens. Your body releases many chemicals, one of which is called histamine. Histamine is the most abundantly released chemical and is responsible for causing most of your symptoms. Certain body patterns and metabolic states have been associated with production of allergic symptoms. A person inherits the predisposition to allergy, rather than the specific allergy. Therefore it is the tendency to become allergic to a foreign substance, that is inherited. The fact that allergic disease is has many causes, has led to medical confusion. Since no single cause can be found, allergic symptoms are often ignored or attributed to mental or emotional stress.

 Immune system is where inflammation begins. Your immune system kicks into action whenever a harmful substance known as an antigen enters your body. Some common antigens are viruses, parasites and bacteria. Every antigen has a specific corresponding anti-body or immunoglobulin, which is like the first responders at an accident. There are five types of immunoglobins: lgA, lgE, lgG, lgM, lgD. However, the three important ones related to allergies are:

• Immunoglobin E (lgE) is the main responder in allergic reactions and involved in reactions to parasites.
• Immunoglobin A (lgA) is the immune protein that covers the mucous membrane linings including the digestive tract, sinuses, tears, gut juices, mother’s milk, and breathing passages. They bathe the body surface and prevent pathogen entry.
• Immunoglobin G (lgG) is the main and most abundant antibody of immune proteins in plasma. They can cross the placenta.

 There are two common types of allergies: airborne allergy and food allergy. Airborne allergy is about when an unfamiliar substance, such as pollens, dust, and molds, enters the body for the first time, the body begins the process of manufacturing antibodies specific to that substance. These lgE antibodies will be ready to act the next time the substance is encountered. Meanwhile, they attach themselves to mast cells of the immune system. Each mast cell is coated with hundreds of thousands of lgE antibodies. When the allergen again enters the body and is exposed to these lgE coated mast cells, an allergic reaction occurs releasing inflammatory substances and triggering a cascade of allergic symptoms such as watering eyes, runny nose, sinus congestion and pain, itching rash, wheezing.

 Instead of lgE antibody being produced when a food allergen is ingested, a free-floating antibody called secretory lgA is released into the digestive tract. The lgA coats the particles of the offending food entering the small intestine from the stomach. When a food allergen and the secretory lgA antibody combine, it stimulates the secretion of a thick, protective mucus coating along the mucosal lining of the intestine. Then, as the allergic food chemically bonds with the mast-cell antibodies specific to it, powerful chemicals are suddenly released, occurring an allergic reaction. Food allergy has followed a different pathway in the body and used different chemicals than the airborne reaction.

 However, the food allergen reaction is more insidious than the airorne reaction. Whereas the airborne reaction is fairly local (eyes, nose, sinuses, air passages), the food allergen reaction has far-reaching consequences. For example, the released inflammatory prostaglandins cause the stomach to secrete less hydrochloric acid. Hydrochloric acid is necessary to stimulate the production of pepsinogen, a protein-digesting enzyme. Without sufficient pepsinogen, protein cannot be properly digested. This lessened production of hydrochloric acid also causes the food to enter the small intestine in an under acid state. Without sufficient acid, the pancreas under produces the bicarbonate necessary to alkalinize the food since it depends on the acid to stimulate this production. With less bicarbonate, the pancreas is also not stimulated to produce and release the necessary digestive enzymes to complete digestion. Because the food is not alkalinized, the original under-acidic food now remains in a relative over-acidic state in the small intestine.

A healthy intestine does more than just digest food. It is an immune barrier that protects the body from foreign invaders. A healthy intestinal lining allows only properly digested fats, proteins and starches to pass through so that they can be assimilated. At the same time it also provides a barrier to keep out unwanted, indigested molecules, bacterial products, and other foreign substances. In between the cells of the intestine are normally tight fitting junctions, which do not allow large molecules to pass through. However, when this area becomes irritated or inflamed, these junctions between the cells loosen up and permit larger molecules to pass through. The immune system interprets these large molecules as foreign invaders and this stimulates an antibody reaction. Some of the substances that may pass through a damaged intestinal lining are bacteria and fungus, toxic molecules including those produced by the process of digestion, and undigested food particles. These may pass directly though the weakened junctions and into the bloodstream. The small intestine cannot normally complete digestion, absorption and assimilation processes if humans have unfavorable nutrients, leading to decreased immunity.

 Allergy appears to increase with advancing age. As a person ages, he tends to have weekend resistance due to a weakened immune system, various stages of organ degeneration, and having had more time accumulate toxic substances often increase as a person ages since they accumulate over time from the person’s eating patterns.

Emotionally stressful situations can lead to diminished immune system function. Physical stress can increase nutrient requirements, leading to deficiency. Nutrient-deficiency further stresses the immune system. Poor diet affects the body’s ability to fight disease. It leaves the body unprotected. As one organ or body system loses its ability to function at peak performance, it affects other organs and systems. These other organs and systems must now do more work to compensate for the one that is stressed. As malnutrition continues, these accommodating organs and systems become stressed and lose their ability to function optimally. You cannot affect one part of the body without affecting other parts.

Reference:

1. Allergies Disease in Disguise by Carolee Bateson-Koch, DC ND
2. Nutrition & Healing by Dr. Glenn S. Rothefeld, MD