By Wendy Hodsdon, ND

A food allergy, in the broadest sense, is an adverse reaction to food. The reaction can be the body's inappropriate immune response to a food or its reaction to a protein, starch, or food additive, such as the colorings or preservatives in food.

Common food allergy triggers

The body can react to any food in theory, but there are some commonly observed foods to which many people have an allergic reaction. The most common food allergens include:

• Alcohol
• Caffeine
• Cane sugar
• Citrus
• Dairy wheat
• Eggs
• Gluten corn
• Peanuts
• Potatoes
• Soy
• Tree nuts
• Yeast

When a person eats any of these foods multiple times per day, the risk of developing a reaction to that food is higher. Since many of these foods are common ingredients in processed foods, exposure for some can be more frequent.

Food allergy symptoms

Food allergy symptoms are associated with many common diseases and can affect any system in the body. Symptoms of food allergies can range from being mildly uncomfortable to debilitating. Diseases caused by food allergens include celiac disease (from gluten intolerance), some types of arthritis, and chronic infection. General symptoms of food allergies include fatigue, headaches, low blood sugar, edema, irregular heart beats, depression, anxiety, and chronic fatigue. A person's symptoms depend on the part of their immune system that is activated by the allergen, as well as the points of weakness in their individual body. Often the weak organ system manifests symptoms first because it responds first to signs of inflammation. Here is a list of common food allergy symptoms by body system:

• Skin. The body sometimes tries to eliminate through the skin what it can not digest easily. When it does, the following symptoms may result: acne, eczema, hives, itching, and skin rash.

• Digestion. If digestion is weak, chronic diarrhea, ulcers, irritation of the stomach lining, canker sores, irritable bowel syndrome, celiac disease, and ulcerative colitis may appear.
• Mental/Emotional. If the nervous system is weak, mental /emotional symptoms often result, such as: anxiety, depression, hyperactivity, inability to concentrate, insomnia, irritability, mental confusion, fatigue and even seizures.
• Respiratory. If the lungs are weak asthma, chronic bronchitis and wheezing may result.
• Musculoskeletal. If the muscles and bones are weak, joint pain, back pain, arthritis, and bursitis may become worse up to three days after eating a food to which the body has an allergic reaction. The joints in the body are affected by the toxins present from poorly digested foods.
• Urinary Tract. If the urinary tract is weak chronic bladder infections, irritation of the kidneys, and bed wetting may occur.
• Immune System. Frequent infections, including ear infections, sinusitis and post-nasal drip, as well as itchy nose or throat and watery eyes, can result if the immune system is involved. Immune system over-reaction is the source of many of the symptoms of food allergies, and when the body is busy reacting to an allergen, it has a harder time fighting infection.

Other food allergy indicators

Some other things to watch for that may indicate food allergies include dark circles under the eyes, puffiness around the eyes and horizontal creases in the lower eyelid, chronic fluid retention, and chronically swollen glands. While learning to change one's diet can be difficult, the results can greatly improve health. Many people find they lose weight, have less nasal congestion, fewer seasonal allergy symptoms, less pain, and more energy once they identify and eliminate foods to which they are allergic from their diet.

For further general information on food allergies see the following article from TheDietChannel: Food Allergies: General Info.