Overview: Basic Information about Food Sensitivity

Updated: May 2003

Article Summary

Food sensitivity results when a food in the diet causes an increased level of a body chemical. Food allergies are an immune system reaction to a food. Food intolerance is usually caused by low levels of enzymes that break food down. Skin, digestion and respiratory problems are the most common symptoms of food sensitivity.

What is food sensitivity?

The body is made of many different chemicals. Each chemical has a specific function in the body. When levels of certain chemicals get too high, unpleasant side effects may occur.

Food sensitivity results when a food in the diet causes an increase in the level of a body chemical. Food sensitivity can be classified as food allergy or food intolerance.

What is food allergy?

Food allergy results when the immune system reacts to a food. The immune system thinks that the food is harmful and launches a chemical attack when the food enters the body. The allergic symptoms are caused by the chemicals released during the immune system reaction.

What is food Intolerance?

Food intolerance is a reaction to a food that does not involve the immune system. In other words, you feel sick when you consume the food, but your immune system is not causing the symptoms. Food intolerance is usually caused by low levels of enzymes. This decreases the body’s ability to break down the chemicals in the food.

What are the symptoms of food sensitivity?

The most common symptoms of food sensitivity are:

	Digestion problems (example: diarrhea, bloating, stomach pains)
	Skin problems (example: hives, eczema, itchy skin)
	Breathing problems (example: asthma)
	The role of food sensitivity in many other symptoms is controversial. These symptoms include, but are not limited to:
	Behavioural problems
	Fibromyalgia
	Chronic fatigue syndrome

Some people have reported significant benefit from following a restricted diet. Unfortunately, research studies have not been able to verify the benefit of diet changes for many of these symptoms.

Food sensitivity may be the single cause or just one of several contributing factors to a symptom. For example, eczema is a common skin rash that can be caused by many factors. Food allergy is only one of these factors. In severe food allergy, such as peanut allergy, food is usually the single cause of the reaction.

You should always see your medical doctor if you suspect a food sensitivity. The symptoms described above may be related to many factors, not just food sensitivity. It is very important to have your symptoms properly diagnosed. If you do not discuss your symptoms with your medical doctor, the best treatment may be delayed.

What foods are troublesome?

Common foods that cause sensitivities are:

	egg whites
	chocolate
	fish
	gluten (found in wheat, rye, oats and barley)
	milk
	nuts
	soy bean
	shellfish
	strawberries
	tomatoes

However, any food can cause sensitivity. Food allergies result from an immune response to the protein in a food. Food intolerances usually result from the body’s decreased ability to break down a component of the food.