The terms food intolerance and food allergies are often confused. Food allergies occur when the body has strong, immediate reactions to a food. The immune system is directly involved with a food allergy. With a food intolerance, though, the body has an unpleasant reaction to the food or additives.

Since not all reactions can be covered by the term food allergy, doctors use the term food intolerance to describe those unfavorable reactions that don't involve the immune response system. Allergy tests are used to detect allergens. Sometimes food intolerance is just the result of too much of the same thing over a long period.

Non-immune responses are also possible with some foods. You should be familiar with generic toxicity. This would be the body's reaction to known poisons such as arsenic, lead, and mercury. These poisons can occur naturally and show up in food when you least expect them to.

This can result in a number of health risks. Indeed, in the worst case, one can grow ill or even die due to ingested impurities. A second group is those who carry mutations for specific digestive enzymes. The problems they regularly encounter are less apparent than those who have more violent food allergies.

Lactose intolerance is a familiar instance. There are those people whose bodies cannot digest milk because they lack the enzyme called lactose, which is needed to absorb the sugar lactose in milk. Most of us have levels high in this enzyme so we can tolerate milk and not have unpleasant side effects.

An alternative type of food intolerance comes from a negative reaction to chemicals found in food. These substances may be of natural or artificial origin. The symptoms are often the same as common food allergies, so physicians must be particularly careful when diagnosing an individual showing some or all of these troubles.

There are various things which come under the food additives category. They include substances like preservatives, flavoring agents, coloring agents etc. Some familiar examples include tartrazine, MSG or monosodium glutamate, sulphur dioxide as well as benzoates. When chemical reactions are involved with respect to food or food additives, they are not actually allergic reactions since here the body's immune system is not involved.