Written By Samar Tarabay, Quest Nutritionist

Allergies affect the quality of lives of millions of people around the world and even if you lead a healthy lifestyle allergies may still be unavoidable. Allergies can make you feel tired and sleepy after eating, or can make you suffer from skin problems even though you never eat junk food. They may also give you frequent headaches or periods of depression, and the worse part is not knowing that the allergy actually exists.

We are capable of developing an allergy co hundreds of substances that we came into contact with every day and the symptoms can range from mild to quite severe which may cause harm to the person, both physically and emotionally.

What is an allergy?

The immune system has an immeasurable responsibility. It carries out the process of keeping the body protected from disease and invasion by harmful substances. The immune system has the ability to make a distinction between self and 'a non-self molecule as each individual possesses a certain (issue type. Therefore any 'non-self molecules which enter the blood stream will be attacked and destroyed leaving the 'self molecules free to carry out their normal functions. An allergic reaction is caused when the immune system mistakes a non-toxic substance (such as food) as a non-self molecule, which it then attacks and subsequently causes inflammatory reactions in the body. The substances which bring about an immune reaction are called allergens. When the body encounters allergens, the immune system reacts by producing antibodies or releasing certain chemicals like histamines.

These histamines, along with other substances are released into the system and cause inflammatory reactions which lead to allergy symptoms such as a runny nose and watery eyes. The expression of an allergic reaction will typically occur in the general location where the immune system attacks the allergen.

Common allergies include animal hair, pollen, moulds, dairy products, shellfish, wheat and eggs.

What are the symptoms?

When we think of an allergic reaction what usually comes to mind is a person sneezing, nose running and eyes watering, as a result of coming into contact with something he or she is allergic to, but allergies may result in much more severe reactions than expected such as anaphylactic shock which can be fatal.

Some of the possible symptoms commonly produced include sneezing, itching and watery eyes, runny nose (clear discharge), congested nose, hives, skin rash or irritation, headaches, increased heart beat, arthritis, asthma and depression.

Food Allergy

Adults that Suffer from food allergies are about one percent of the total population and only about three per cent of children have allergic reactions to foods. Many people may react to foods in a certain way but it is important to know if that reaction is a result of food allergy or food intolerance. Food allergies are caused by immunologic reactions to foods. The immune system is not responsible for the symptoms of food intolerance, even though these symptoms are similar to those of a food allergy.

It is extremely important for people who have true food allergies to identify them and eliminate them from their diet because the allergic reactions, can cause devastating illness and, in some cases, be fatal. Many fatalities are caused by peanut allergy which is often described as anaphylactic shock.

During digestion, the macro nutrients (proteins, carbohydrates and fats) are only intended to enter the bloodstream in their usable form. Protein is usable in the form of amino acids, carbohydrates as simple sugars, and fats as fatty acids. Once the body has successfully broken down the macro-nutrients, the resulting substances are generally unable to present an allergy related problem to the body. An allergic reaction occurs when the macronutrients ate not completely broken down before they have the opportunity to be absorbed through the intestinal walls.

However, due to the nature of the immune system, almost all allergic reactions are caused by the absorption of undigested protein. This is because the immune cells have been designed to detect extremely small protein molecules which are released by harmful bacteria once inside the body. If, for example, a protein such as gluten (derived from wheat and other grains) is not adequately digested into the free amino acids and remains as a protein when it is absorbed through the intestinal wall, then a reaction occurs. The while blood cells are accustomed to the entry of amino adds into the bloodstream from the moment of conception, and thus amino acids are not treated as invaders, but large proteins are not intended to gain entry through, the intestinal wall and subsequently into the blood stream. If they somehow force their way through the intestinal wall, they will be attacked by the white blood cells of the immune system.

An allergic reaction involves two features of the human immune response. One is the production of immunoglobulin E (IgE), a type of protein called an antibody that circulates through the blood. The other is the mast cell, a specific cell that occurs in all body tissues but is especially common in areas of the body that are typical sites of allergic reactions, including the nose and throat, lungs, skin, and gastrointestinal tract.

The ability of an individual to form IgE against food has been found to be an inherited predisposition. In other words, if your parents suffer from allergies, then your chance of developing an allergy yourself greatly increases. The allergies suffered by the parents may be different from the allergies which develop in the children, which mean that specific allergies themselves are not passed onto the offspring, but the offspring are more prone to allergies in general.

An allergy to a certain food will only occur once the person has been exposed to that food and therefore begins to produce IgE. This is described as the sensitisation period which basically means that the person is sensitive to that food. Therefore every time the food is ingested in the future, a reaction will occur, if the food is consumed again, it will trigger the release of IgE. IgE then attaches itself to the mast cells which in turn release histamine, and, depending on the area of the body affected, the symptoms will vary.

If the mast cells of the ears, nose or throat are affected, a person may feel an itching in the mouth and may have trouble breathing and swallowing. If the affected mast cells are in the gastrointestinal tract, the person may have abdominal discomfort and diarrhoea.

Nutritional Help

The most effective method against food allergies is to avoid the foods responsible. However, in practice, this is not always possible and it is particularly difficult when eating out.

Many pharmaceutical medications for allergic reactions are designed to possess an antihistamine property. This is because the release of histamine causes the symptoms experienced by allergy sufferers and therefore, if the actions of histamine can be prevented, the severity of the symptoms will lessen.

However, numerous studies have shown that there are many nutrients which also possess anti-histamine actions. One such nutrient is vitamin C, along with certain plant compounds called bioflavonoids. Some studies indicate that vitamin C may have some abilities as an antihistamine and therefore may be useful in decreasing the severity of allergy symptoms. Dietary sources of vitamin C include almost all fruits; however, the vitamin C content of foods may not be sufficient to be effective against allergies, to obtain a high level of vitamin C during the day (1000mg/day) it may be beneficial to consider supplements. The most effective vitamin C supplements would be those with added bioflavonoids to enhance their antihistamine actions.

A study found that quercetin, a bioflavonoid, has antihistamine properties and was able to reduce the release of histamine from mast cells (the process which causes the symptoms of an allergy). In this respect consuming foods high in quercetin, such as most of the berry family, would be beneficial and at least two portions of berries, along with other fruits, should be consumed every day.

Another study found that the compounds in the herb feverfew also have the ability to inhibit the release of histamine from mast cells, and may also be useful to help prevent allergic reactions.

It may also be beneficial to avoid foods which are associated with the production of mucus, such as dairy products, as this may help reduce the quantity of mucus released during a reaction to an allergen.

Allergies affect many people throughout the population causing a variety of symptoms and serious allergies can even be fatal. The most effective way of avoiding such symptoms is to avoid the allergen but when this is not possible, nutritional supplements may be considered.

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