Food: Perspectives and Perceptions
When you think of “food”, a series of images can flash through your mind; these are primarily perceptions of what food may mean to you. These perceptions could be based on our experiences with different kinds of food. There are always some foods we relish while a few others which our individual systems do not easily accept. Each one of us is definitely uncomfortable with consuming certain food items; these may differ from person to person. You may feel uneasy upon eating prawns or peas; while it may spell out “delicacy” for someone else. On this note, now let’s drive the discussion specifically to conditions wherein we become either “allergic” or “intolerant” to certain food products.
The demarcation between Food Allergy and Food Intolerance
Before we delve deeper into this subject; it is critical to understand the difference between the terms food allergy and intolerance. Food allergy is a less commonly occurring but more reported phenomenon, seen in around 2% of all individuals and mainly in the young and in infants. It occurs almost immediately after consumption of food containing the allergen and occurs through an immune response brought about by IgE class of antibodies. In sharp contrast to this, of late it is becoming clear that intolerance to food occurs much more frequently in about 10 — 25% of the population, any age group can be affected, and the response is mediated through IgG class of antibodies. Intolerance takes a long time to develop and manifest as is the case with most IgG mediated immune response, unlike allergy which shows up pretty soon after exposure.
Again, food allergy manifests as discernible conditions like severe abdominal cramps, rashes etc; whereas intolerance leads to delayed manifestations ranging from vague abdominal discomfort, constipation or loose motion, to headache, mood swings or irritability. In children afflicted with chronic bowel diseases like celiac or inflammatory bowel disease (IBD) food intolerance is quite commonly seen. Recent research has shown that autistic children often have intolerance to several food items. In adult patients of IBD and irritable bowel syndrome, occurrence of food intolerance is a oft-reported phenomenon.
The “Food Detect” and “Food Intolerance” tests
Repeated episodes of rapid development of discomfort or abnormal symptoms upon consuming certain food products should initially raise a suspicion of a probable allergy. In this case, it is recommended to undergo in vitro testing for the suspected allergen. This test will measure IgE antibody levels against the suspected causative allergen. If in vitro allergy testing does not yield any positive findings and yet episodes of discomfort recur or the symptoms do not match that of conventional allergy presentations, further investigations can be done to check for food intolerance. In this regard, it is relevant to mention two blood tests called “Food Detect” and “Food Intolerance”. Both these tests are indicated in food intolerance cases; while Food Detect is a semi-quantitative screening tool which tests your blood sample for 53 known India specific food items, the Food Intolerance assay is a quantitative test which checks for around 220 internationally recognized intolerant food substances.
The Food Intolerance test puts forth a quantitative result by measuring the IgG levels in an individual’s blood against a food substance and based on these IgG values the foods are categorized into normal, borderline or intolerance levels for a particular patient. Food Detect being a screening assay is performed by a simple technique called Immunochromatography and the test report can be available to the patient on the same day of testing. Food Intolerance testing is done by an advanced diagnostic method called protein microarray and the patient receives the test result in 2 days.
SRL Diagnostics’ retrospective study on results of the Food Intolerance test: A quick snapshot
At this point, it would be interesting to have a look at a retrospective research study that was conducted at R&D of SRL Diagnostics. The objective of this study was to determine the most common substances associated with food intolerance in select Indian population. In a study sample of 200 symptomatic individuals who got the Food Intolerance test done at SRL, a total of 20 such frequently intolerance-triggering food substances were identified during this data analysis. These have been diagrammatically presented in the pie chart below:
From the data presented in the pie chart above, a notably high percentage of the study population was found to be intolerant to pea, cola nut, yeast, cow’s milk, bean and egg white. It is noteworthy here that these food items are very commonly consumed in our everyday diet and a high occurrence of intolerance to such common food types; like pea, milk and egg white; is a matter of concern. If you have a more closer look at the statistics and food items in the pie chart, it seems alarming that more than 40% and 50% of the study population showed intolerance towards cereals like rice and wheat respectively. These cereals form a part of the daily staple Indian diet and a high intolerance level towards these warrants our medical attention. Based on this data, we believe that further large scale, multicentric pan India studies should be done to better elicit the patterns of food intolerance in India.
Food: Make it fodder for health, not for disease
Food is fuel for health. However, when food becomes the cause of a health problem, the situation becomes dicey and warrants your attention. On the occasion of World Food Day, 16th October; we reiterate the importance of consuming the right foodstuffs, being aware of the food products that make you uncomfortable upon consumption, testing yourself for such suspected food allergies and intolerance and guarding yourself from the causative triggers. The ancient Greek physician Hippocrates, who is regarded as one of the most revered figures in medicine even today, centuries ago, doled out precious medical advice about the importance of good and appropriate food consumption. He said, “Let food be thy medicine and medicine be thy food” – a theme that needs to be re-inforced this World Food Day.