You may have experienced abnormal reactions to food at some point in your life. Diarrhoea, bloating and swelling of the throat are just some of the symptoms of adverse reactions to food. However, understanding the difference between food intolerance and food allergies is crucial to helping make the right changes in your diet and effectively managing your symptoms.
Food allergies are more straightforward. They are reactions to specific foods that can be severe enough to cause asphyxiation or even death. Foods like peanuts or seafood commonly cause allergic reactions. Usually, someone who suffers from allergies will experience a fairly quick reaction to what they just consumed.
There are two tests performed by allergists to diagnose food allergies: IgE blood test and a skin test – both of which have been proven via scientific research. Still, professionals will often conduct a food test in the office for a more accurate diagnosis.
Food intolerance, also known as non-IgE mediated food hypersensitivity or non-allergic food hypersensitivity, refers to difficulty in digesting certain foods. It is a more complex problem and still leaves even doctors with many questions. Symptoms of food intolerance tend to take longer to appear than symptoms of allergies.
Sometimes, it is not the food itself, but a substance within foods that can increase the frequency and severity of symptoms like migraine headaches, hives, rashes or stomach upset. Diagnosis can be made even more complicated by coincidences – as we spend many of our waking hours eating or drinking, other factors may come into play that seem to cause a food intolerance reaction, while masking the real problem itself.
Food intolerance has a cumulative effect of upsetting your immune system and causing inflammation in the body. If you have an autoimmune disease, food intolerances will make your symptoms much worse. Because food intolerance takes up to 72 hours to manifest its symptoms, an elimination diet is usually the path recommended to identify the triggers. The main causes of food intolerance include the following:
• Lack of enzymes – Specific enzymes are needed to digest foods fully, and almost all foods require an enzyme to enable proper digestion.
According to experts, enzyme deficiencies are a common reason for food intolerance. For example, people who are lactose intolerant most likely do not produce enough lactase, an enzyme that breaks down milk sugar (lactose) into smaller molecules for absorption. If lactose stays in the digestive tract for too long, it causes bloating and diarrhoea.
• Chemical causes – Some of us are more intolerant of certain chemicals that are found in our food and drink, like amines in some cheeses, and caffeine in coffee or tea. It is best to avoid certain foods, or try to find alternatives without the chemicals that you might be intolerant of.
• Food poisoning –Some foods have naturally-occurring chemicals that can cause diarrhoea, nausea and vomiting.
For example, aflatoxins (toxins produced by certain types of fungi) can cause extremely unpleasant digestive problems. It is poisonous, has high carcinogenic potential and are found in foods like peanuts, beans and corn.
• Histamine in some foods – Foods that are not properly stored, like fish, can have an accumulation of histamine as they begin to decay. You might be sensitive to this naturally-occurring histamine, and develop skin rashes and food poisoning symptoms.
• Salicylates present in many foods – Salicylate intolerance is a reaction to normal amounts of ingested salicylate, which is derived from salicylic acid.
It occurs naturally in plants as a defence mechanism against harmful bacteria, fungi, insects and diseases. Most of the time, we are consuming some amount of foods with salicylate without experiencing adverse effects, but intolerant individuals should avoid foods that contain high levels.
Salicylates occur in most plant-sourced foods, including many fruits and vegetables, spices, herbs and tea. Processed foods with flavour additives are usually high in salicylates.
Leaky gut and food intolerance
Food intolerances are often caused by intestinal permeability (aka leaky gut). Our intestinal lining is vital to our health. It’s designed to let needed nutrients into our bloodsteam, while keeping out everything that’s harmful to our health. Here’s the problem: a leaky gut and the autoimmune system go hand in hand. You rarely find one without the other.
With a leaky gut, our intestinal lining becomes too permeable, letting things into our bloodstream that don’t belong there. Amino acids are a nutrient meant to be allowed through. They are the building blocks of proteins in our food, and the building blocks of cells in our bodies. They’re tiny and wonderful, and we need them.
With a leaky gut, our bodies let proteins through before they’ve been completely broken down into amino acids. We’re not talking big chunks of food – just molecules bigger than they should be, in a form our body can’t recognise as food.
So, the body mounts a defence by activating the immune system and ramping up inflammation. Not a good situation for someone with autoimmune disease.
Diagnosing food intolerance
A food diary is the best way to track any pattern of food intolerance. Keep a small book with you to jot down the foods you eat. Note any symptoms you experience when they occur. Your diary information may help a dietitian advise you on the foods that are causing problems, and steps to take that may alleviate problems.
Intolerances to certain substances can determine coeliac disease or lactose intolerance, but apart from that, there is no accurate test to determine food intolerance. Most people go on an exclusion diet, also known as an elimination or diagnostic diet. It takes time to see results, but is effective in determining the culprit foods.
In a typical exclusion diet, a suspected food is removed from your diet, usually between two to three weeks. You will notice if the reactions subside during this time; and if they return when you bring the food back into your diet, then it is likely that this food is causing you trouble.
Testing for food intolerance
Research has shown that food intolerance tests can be linked to Ig antibodies raised by your immune system. Your doctor may ask you to do a blood test to measure specific IgG antibodies in your blood. Blood is taken and the IgG antibodies are measured. It eliminates the guesswork as to which are the trigger foods that are causing the food intolerance.
However, do not forget your nutritional balance during the elimination period, as a restricted diet can diminish adequate nutrition, especially in children. The best current treatment for food intolerance is to undergo an elimination diets with the supervision of your doctor to either avoid certain foods, or eat them less often and in smaller amounts, as well as taking supplements that may help digestion.
By Datuk Dr Nor Ashikin Mokhtar
By Published in Star Newspaper, December 11, 2016
