Difference between Allergy and Intolerance

It is common for people to have physical reactions to specific foods like feeling uncomfortable, unpleasant or get sick after eating certain foods. These physical reactions though similar in some ways but are mainly caused by two different conditions: food Intolerance and food allergy. So, people often confuse the food allergy with food intolerance because they cause similar symptoms, but these are different conditions. Let us see how one differs from another!

Food Intolerance:

Food intolerance is also known as non-allergic food hypersensitivity. It is an adverse physical reaction to specific foods which are not properly digested by our body or disturb our digestive system in some way. Food intolerance does not involve the body?s immune system. It occurs when the digestive system does not produce the required enzymes or chemicals required to break down and digest the food.

So, if a person's body lacks specific enzymes necessary to break down a specific food, he or she may suffer from food intolerance after consuming that food. For example, lactose intolerance occurs when a person's body lacks the enzyme required to digest milk. Such people usually feel uncomfortable and unpleasant after consuming dairy products as their digestive system has to struggle to digest the milk.

Food intolerance is not a life-threatening condition as it produces less severe symptoms than food allergy. It can be an immediate response to food or may take hours, days or even weeks to produce symptoms. Food intolerance does not occur if food is consumed in small amount, it usually occurs when one consumes the intolerance-causing food in a large amount.

Common Food Intolerance Symptoms:

Nausea
Gas
Cramps
Abdominal pain
Diarrhea
Headaches
Irritability

Food Allergy:

Food allergy is an adverse immune response to specific foods. It occurs when our body's immune system, which is designed to fight infections, mistakes the food as antigens (infectious agents) and produces antt is baibodies against it. Isically an allergic reaction which starts in our body when we consume specific types of food. In this reaction, chemicals called histamines are released in the body in response to the food consumed by a person. In some cases, it may cause life-threatening symptoms like anaphylaxis. The major foods that cause 90 percent of food allergies include milk, egg, fish, peanuts, tree nuts, shell fish, wheat and soy. If you are allergic to a food, even a small amount of that food can trigger an allergic reaction. Furthermore, it is an immediate response to food, occurs within few seconds, minutes or hours.

Common Food Allergy Symptoms:

Difficult breathing
Throat tightness
Coughing
Vomiting
Abdominal pain
Hives
Chest pain
Low blood pressure

Based on the above information, some of the key differences between Food Intolerance and Food Allergy are as follows:

Food Intolerance	Food Allergy
Body's adverse reaction to a particular food.	Body's allergic reaction or adverse immune response to a specific food.
Digestive system lacks certain enzymes or chemicals required to properly digest a particular food	Immune system treats food proteins as infectious agents and generates antibodies to destroy them
Diagnosis involves hydrogen breath testing, elimination diets, Elisa testing.	Diagnosed by skin prick test, blood test, elimination diet test, oral food challenge test
It is a slow physical reaction as symptoms may take few hours, days or weeks to appear.	It is an immediate response, as symptoms occur within few seconds or hour after consuming the food.
Symptoms are less severe such as nausea, bloating, diarrhea etc.	It may cause severe symptoms such as difficulty breathing, hives, low blood pressure and a life-threatening reaction called anaphylaxis.
It is estimated to affect 2-20% population.	It is estimated to affect 6-8% of children under the age 4 and around 4% of adults.
It is not a life-threatening condition.	It can be a life-threatening condition.
Consuming food in a small amount does not cause food intolerance	It occurs even if one consumes a small amount of allergy-causing food.