God has gifted us this wonderful world with the dominion of all things on it. We can feast upon the multitude of foodstuff available at our convenience. With this boon comes a small rider. Consuming some of these foodstuffs. gives rise to conditions known broadly as food allergy and food intolerance.
We will first discuss food allergies than food intolerance. To understand food allergies you first need to know what an allergy is. . What you have to remember is that allergy is caused by your body’s own immune system running amok The human body’s own immune system consists of two types of cells B lymphocytes and T lymphocytes. The B lymphocytes produce antibodies which are protein molecules called immunoglobulins. They bind to the cell membrane of the offending invader cell eg bacterial cell, rupturing the cell membrane thus killing the cell. The T lymphocytes produce cells that phagocytose or engulf the invading cell thus destroying it. Now the question arises that from where do these lymphocytes get the information about which cell to attack and which not to. The answer lies in the fact that copies of the cells primed for one class of pathogens are stored as memory or template after an initial attack ready for the next assault.
Likewise, memory cells are formed for the food molecules after the first round of exposure. When there is another round of exposure the memory cells mount an exaggerated response to the food molecule, so much so that the body’s own tissues are attacked. This is the basis for allergic responses.
So in a nutshell it can be said that food allergies are abnormal immune responses against food protein. There are some classic symptoms due to food allergies. It includes angioedema which is soft tissue swelling around the eyes, lips, and tongue. Sometimes the tongue may be so swollen so as to obstruct the upper airway leading to impairment of breathing. Another symptom is hives or small elevated plaques all over the body together with itching of the throat, mouth, eyes, and skin. Nausea, vomiting, and abdominal pain are common, together with abdominal pain, rhinorrhea and wheezing. A severe life-threatening form is an anaphylaxis where severe bronchoconstriction leads to respiratory failure. Ninety percent of food allergies can be attributed to the following substances which are egg, peanut, treenut, seafood, shellfish, soy, wheat, and allergy to milk. The most common food allergies in children are initiated by consuming milk, eggs, treenuts, and peanuts.
These allergies are mediated by the immunoglobulin molecule IgE. Most of these molecules respond to simple anti-allergic medications of pheniramine malleate or administration of steroids. Other more serious cases like anaphylaxis respond to injections of adrenaline.
So much for food allergies. Let us now discuss food intolerance.
Food intolerance differs from food allergy in the fact it is not a true allergy and is not mediated by IgE. If the immune system is involved it is generally by mediation by IgG.molecules.
Food intolerance is a physiological response to foodstuff as it results from the absence of enzymes and chemicals needed to digest or metabolize the food.
Here is a list of the common food intolerances
- Metabolic food reactions result from inborn or acquired defects in the metabolism of nutrients. Examples are diabetes mellitus, where the inability to produce insulin leads to an inability to metabolize glucose. lactase deficiency, phenylketonuria, and favism are other examples In phenylketonuria there is an inability to metabolize the amino acid phenylalanine which accumulates in the urine. Lactase deficiency is the inability to metabolize lactose, a sugar present in milk. whereas favism displays a hemolytic reaction after consumption of broad beans.
- Pharmacological reactions—These are reactions of drug consumption and include common drugs such as salicylates, which is the component of aspirin, and penicillin, the common antibiotic.
- Common food intolerance is an intolerance to a wheat protein called gluten leading to Coeliac disease.
- Body responses to food intolerances include some of the same symptoms found in responses to food allergy, together with some unique responses for specific intolerances.
Therefore it can be seen that food allergies and food intolerances stick like a thorn in our side in our gastronomical sojourn in this world. Some of the results can be irritating at the most, some life-threatening but with a little caution, we can survive.