Food Intolerance Testing
An increasing number of tests are appearing on the market that claim to be able to identify food intolerance problems. Inevitably these tests cost large amounts of money. Do they work?
The simple answer is sometimes.
This article looks at the complexity of food intolerance and explains why many forms of testing are inadequate.
Food Intolerance
In respect of food intolerance it is essential to remember that you can be intolerant of any of the following:
- A complete food such as milk, soya, apple, egg, pork, wheat, mushroom, chicken, lettuce.
- A naturally occurring chemical such as Salicylate in many herbs, fruit and vegetables, Tyramine in aged meat, cheeses and wine, Purines in protein foods, amines in cooked foods, Solanine in vegetables, or naturally occurring MSG (monosodium glutamate).
- An added ingredient that does not occur naturally in the food - such as a preservative, colouring, flavour or antioxidant.
- In a complex food, i.e. any processed food, you could be sensitive to one of the ingredients. For example, in bread it is possible to react to wheat, preservatives, yeast, or bleaching agents.
Do any of the currently available tests check for all of these? NO.
Testing
Most commercial food intolerance testing focuses on a limited number of foods (ranging between 30 and 250). Some test for IgG antibodies in the blood which sounds very scientific but unlike the IgE testing for allergies which has been scientifically proved there is no such evidence to support the accuracy of IgG testing.
Other methods such as the Vega test, the Leucocytotoxic test, Hair analysis and Applied Kinesiology use different methods but, once again, none of these have been proved to be effective.
The end result of many of these tests is a list of foods to avoid which will inevitably lead to a restricted diet. I am very uneasy about these lists and would always recommend that each of the foods is checked individually by eliminating it from the diet and then testing it. If you don't do this you will not know for definite that all of the foods are actually causing you problems and you may restrict your diet unnecessarily.
My other concern about long lists of suspect foods is that it is actually rare for an individual to be intolerant of a whole range of foods. If many foods are implicated the problem is most often one to do with food chemicals (such as salicylates or amines) rather than with individual foods. These tests are unlikely to ever identify these problems for you.
An excellent study by Joneja identifies the difficulties in testing for food allergy and especially for food intolerance. She concludes that no single method of testing can identify all problem foods or the constituents within the food because the immunological, physiological and biochemical reactions that effect food sensitivity are so diverse. Elimination and challenge testing often provide the most accurate results.
Not a Quick Fix
The only accurate and, in my opinion, safe method of testing for food intolerance is to eliminate the suspect food (or reduce the amount of suspect food chemical in the diet) and then, after a number of days, to eat some of the food and monitor your reaction. This is by far slower than having a blood test or a consultation in a health store but it will give you accurate results to work from.
Some doctors can supply guidelines on how to do this form of testing and can also carry out challenge testing with food chemicals. A simple guide to this form of elimination testing is outlined in my own seven step plan. It will not give you a quick fix but it will work for you.
Personal Note
I am Salicylate sensitive, have a minor problem with amines, wheat and milk, react to a whole host of additives, and, strangely enough, to lettuce. No form of current testing whether for allergies or food intolerance would have identified my problems. The method that worked for me was changing my diet gradually, testing individual foods and food chemicals and adjusting my diet, and cooking style, accordingly. If I hadn't done this I could have spent hundreds of pounds and still been none the wiser and still been extremely ill.
You can find out about testing for food intolerance in Change Your Diet and Change Your Life.
REFERENCES
Joneja JM. Food Allergy Testing: Problems in Identification of Allergenic Foods. Can J Diet Pract Res 1999;60(4):222-230.