Food Allergy vs. Intolerance

It’s common for people to have adverse reactions to some types of food.

These reactions are often called by different names – food intolerance, food hypersensitivity, food allergy – and can create a lot of confusion.

To identify which food is responsible for your symptoms, you will need to keep a diary of all perceived or felt reactions to different foods. This can be in form of photographs, written records and saved labels of suspected pre-packaged foods.

Regardless of the similarities, symptoms of a food allergy tend to be more serious than those of a food intolerance, states Mayo Clinic. However, the presence of the clues listed below will help you differentiate an allergy from intolerance. A qualified medical doctor can assist you distinguish the difference.

Food Allergy

A true food allergy reaction develops when the body perceives the consumed food as harmful and produces specific antibodies (known as IgE antibodies) to combat the allergens present in the ingested food.

In the course of such immune reactions, histamine and other naturally-occurring chemicals are secreted. It is the release of these chemicals that triggers the symptoms collectively known as an allergic reaction. Such manifestations include gut-related symptoms (e.g., diarrhea and stomach ache), respiratory and circulation symptoms (e.g., rapid decline in blood pressure, chest pain and breathing difficulties) and skin reactions such as rash and itching.

Common foods known to trigger allergic reactions include eggs, tree nuts (such as almonds), peanuts, fish, sesame, milk and shellfish. You should take care because any food can trigger an allergic reaction and some foods are more likely to trigger allergic reactions in some ethnic or racial groups than in the other.

Food Intolerance

Food intolerance is a condition resulting from sensitivity to certain food additives, celiac disease, recurring stress, poor nutrition intake and/or irritable bowel syndrome.

Some people may lack the enzymes that are vital for breaking food down such as lactase (which helps digest milk). Though food intolerance isn’t life-threatening, it can cause illness and discomfort . Hence, it can negatively affect your social and working life. Moreover, the symptoms associated with food intolerance may have a psychological effect; someone with food intolerances might feel marginalized and may feel as thought they will never recover.

Reactions associated with intolerance do not involve the IgE antibodies as is the case with an allergy. Though the mechanism is unclear, "intolerance reactions" tend to appear several hours after consumption of an offending food. The symptoms include gut symptoms (e.g., diarrhea, bloating and irritable bowel syndrome) and skin complications (e.g., eczema).

Similarities and Differences in Symptoms

Food allergy and intolerance have some mutual symptoms which such as nausea, vomiting, stomach pain and diarrhea. In the same breadth, food allergy and intolerance also have different symptoms. When you ingest food that tends to irritate your stomach or that is unable to be digested by your body, that’s intolerance. Eating such foods triggers symptoms such as heartburn, irritability, bloating and headache.