Choose Topic
Using 0 of 1024 Possible characters
Home »  Living Healthy »  Food Intolerance Vs Food Allergies: Know The Difference

Food Intolerance Vs Food Allergies: Know The Difference

Food intolerance vs food allergies: A food allergy usually comes on suddenly, even a small quantity of food can trigger it. Food intolerance on the other hand usually comes on gradually.

Food Intolerance Vs Food Allergies: Know The Difference

Food intolerance and food allergy are difficult to differentiate as they may cause similar symptoms


  1. Symptoms of food intolerance usually take a longer time to develop
  2. A food allergy usually comes on suddenly
  3. Patterns in the symptoms can help in diagnosing allergies or intolerance

Nutrition is a vital part of life, the food we consume helps maintain our normal metabolism and improves our overall health. It is interesting to note that it is not only our digestive system but also our immune system plays a role in the way our body reacts to various components of our diet says Dr. Saranya Narayan.

There are broadly two adverse reactions by our immune system towards food

1. Food Allergy- In the case of classical food allergies, there is a hypersensitive immune response towards a food component which leads to excessive production of IgE (Immunoglobulin) causing severe symptoms like coughing, inflammation, skin rashes and even anaphylactic shock. This occurs rarely with an estimated incidence of 1-2% globally


Food allergies can cause rashes on skin and inflammation
Photo Credit: iStock

2. Food intolerance- In contrast, food-induced activation of IgG based innate immunity happens more often, can initially be subtle and become more serious over time this phenomenon is also called "Food-Related Immune Stress". The incidence is unknown and reported a prevalence of varies widely from 3 to 35 percent

Also read: What Is Gluten Allergy And Gluten Intolerance: Types, Causes & Treatment

Food intolerance vs food allergies: What's the difference?

The symptoms of food intolerance usually take a longer time to develop, when compared to food allergies. Its commencement is characteristically felt several hours after consumption of the aberrant food and may stay for a long period of time, sometimes even for several months.

A food allergy usually comes on suddenly, even a small quantity of food can trigger it. It happens every time one eats that particular food, and in some cases, it can be life-threatening.

Food intolerance on the other hand usually comes on gradually. It generally happens when an individual eats a lot of a particular food or eats that particular food very often. The most important aspect to note here is that it is not life-threatening.


Lactose intolerance is a kind of food intolerance and it is not life threatening
Photo Credit: iStock

Also read: Good Bacteria Can Prevent Food Allergy; Best Sources Of Good Bacteria/Probiotics

The range of symptoms associated with food allergy includes itching, eczema, urticaria, angioedema, asthma, rhinitis, intestinal symptoms and headache which are clinically defined. The symptoms of Food intolerance, however, are very non-specific and include headaches, rhinitis, diarrhea, flatulence, indigestion, skin abnormalities, weight problems and joint pains which are not usually considered serious in the clinical context but have adverse effects on the quality of life the affected individual.

It is not easy to determine whether somebody has a food intolerance or allergy because the signs and symptoms often overlap. Certain patterns in the symptoms can help a doctor distinguish between the two. Laboratory investigations can play a crucial role in the diagnosis and management of these cases.

A doctor may suggest a skin test and / or a blood test to measure levels of IgE (immunoglobulin E) antibodies to find or rule out a food allergy and detect the allergen causing the problem.

The gold standard for diagnosing food sensitivity was double-blind placebo controlled food elimination tests. The clinical usefulness of this approach is limited by the fact that it is very expensive, lengthy and requires a high level of patient compliance.

Currently thanks to advances in In vitro diagnostics technology, a single serum sample can be assessed for the presence of multiple food components in a matter of few hours to provide a scientifically validated method to guide nutrition experts and patients develop an elimination diet which is the only management strategy against food sensitivity.

Also read: 7 Most Common Food Intolerances

Over to you

Whether it's food intolerance or allergy, it's always good to take precautions. One needs to consult a doctor in case of a food allergy suspicion. If need be, a diagnostic test such as skin prick test and / or a blood test should be done to dispel any doubts. And last but not the least, it's important to understand which foods, and what quantities, causes the symptoms...and then the art lies in either avoiding those foods or having only as much as one can without triggering symptoms.

(Dr. Saranya Narayan is Technical Director at Chief Microbiologist at Neuberg Diagnostics Private Limited, Tamil Nadu)

Listen to the latest songs, only on

Disclaimer: The opinions expressed within this article are the personal opinions of the author. NDTV is not responsible for the accuracy, completeness, suitability, or validity of any information on this article. All information is provided on an as-is basis. The information, facts or opinions appearing in the article do not reflect the views of NDTV and NDTV does not assume any responsibility or liability for the same.


DoctorNDTV is the one stop site for all your health needs providing the most credible health information, health news and tips with expert advice on healthy living, diet plans, informative videos etc. You can get the most relevant and accurate info you need about health problems like diabetes, cancer, pregnancy, HIV and AIDS, weight loss and many other lifestyle diseases. We have a panel of over 350 experts who help us develop content by giving their valuable inputs and bringing to us the latest in the world of healthcare.

................... Advertisement ...................




Using 0 of 1024 Possible characters
Choose Topic

................... Advertisement ...................

--------------------------------Advertisement---------------------------------- -