Q. How Do I Test Myself For Food Intolerances?
A. Food allergies or intolerances are a common cause of fatigue, water retention, digestive problems, and more. Wheat and dairy are the most common, though other foods can also be involved – check out the foods you eat a lot of.
Food intolerances are mainly caused by enzymatic defects in the digestive system, as is the case with lactose intolerance (sensitivity to dairy products). However, they may also result from pharmacological effects of some proteins present in foods (e.g. Histamine).
Prevention and treatment are based on the avoidance of the culprit food. And hence, diagnosis is made using medical history and laboratory tests. To get a final confirmation, you must perform a Double Blind Controlled Food Challenge.
You can check if some foods are a problem by either having a proper blood test or doing an exclusion diet for at least 10 days. That means absolutely no wheat, dairy or whatever you’re testing. Make sure you replace them with similar foods, such as soya or rice milk for cow’s and follow it up by a pulse test. This is similar to Double Blind Controlled Food Challenge.
Here’s how to do it.
- Take your resting pulse.
- Then eat more than normal of the suspect food.
- Retake your pulse after 10 minutes, then 30, and then 60 minutes. If it rises by more than 10 points your body is reacting to the food. Pay particular attention to the symptoms for the next 72 hours.
- Reintroduce foods one at a time, with at least a few days apart. Do not make any other major changes at the same time.
If you do get symptoms or 10-point pulse changed, it would be best to find alternatives for at least three months. Then you can try reintroducing the food, again using the pulse test. This is because the body can ‘unlearn’ an allergy. Rotating a food, which means eating it every fourth or fifth day, is another way to reduce the likelihood of an allergic response.
One of the easiest and most used blood tests for food intolerances is called an IgG ELISA food intolerance test. You can do this using a ‘home test kit’ which involves a pinprick test. Then send it to the laboratory for further testing.
But as we have found after going through a lot of research papers, is that this test may produce false results too .
Reason being, food-specific IgG4 does not indicate (imminent) food allergy or intolerance, rather your body’s response of the immune system after being exposed to food components. So, testing of IgG4 to foods is considered as irrelevant for the laboratory work-up of food allergy or intolerance. And hence, it should not be performed in case of food-related complaints.
Then, what should one do?
Apart from the exclusion diet test for preliminary screening, you can go for a clinical diagnosis.
Allergists are better at making a correct diagnosis than the non-specialist, but the various diagnostic errors and pitfalls suggest that we should be utilising all the available tests more fully in the best interests of the patient.
References:  YOUNG, E. (1994). A population study of food intolerance The Lancet, 343 (8906), 1127-1130 DOI: 10.1016/S0140-6736(94)90234-8. ^Back to Top^  ALLANBOCK, S., SAMPSON, H., ATKINS, F., ZEIGER, R., LEHRER, S., SACHS, M., BUSH, R., & METCAFE, D. (1988). Double-blind, placebo-controlled food challenge (DBPCFC) as an office procedure: A manual Journal of Allergy and Clinical Immunology, 82 (6), 986-997 DOI: 10.1016/0091-6749(88)90135-2. ^Back to Top^  Stephan, O., & Vieths, S. (2004).Development of a Real-Time PCR and a Sandwich ELISA for Detection of Potentially Allergenic Trace Amounts of Peanut () in Processed Foods Journal of Agricultural and Food Chemistry, 52 (12), 3754-3760 DOI: 10.1021/jf035178u. ^Back to Top^  Stapel, S., Asero, R., Ballmer-Weber, B., Knol, E., Strobel, S., Vieths, S., & Kleine-Tebbe, J. (2008). Testing for IgG4 against foods is not recommended as a diagnostic tool: EAACI Task Force Report* Allergy, 63 (7), 793-796 DOI: 10.1111/j.1398-9995.2008.01705.x. ^Back to Top^  Roberts S (2005). Food challenge tests. Archives of disease in childhood, 90 (11), 1207-8 PMID: 16243895. ^Back to Top^  Roberts S (2005). Challenging times for food allergy tests. Archives of disease in childhood, 90 (6), 564-6 PMID: 15908617. ^Back to Top^
Last Updated: June 30th, 2014
Next Scheduled Update: Aug 30th, 2014