Food allergies have become more common in past few decades. Data from CDC say 4 in 100 children have food allergy and the numbers increased almost 20% during the ten year period of 1997-2006. Globally, as many as 10% children under the age of 18 might have some form of food allergy.
Experts believe there are multiple reasons behind the rise in food allergies and sensitivities. Industrialization of food processing, cross-contamination from an increase in variety of foods available, and an increase in hygiene and germ-free life—which compromises the immune system—all contribute to the rising numbers.
A dramatic immune response to peanuts is a well-known food allergy.
Symptoms in such a case include immediate swelling, skin rashes, red eyes, and difficulty in breathing. They require immediate medical attention and can be life threatening. The immunoglobulin E (IgE) antibodies spike within minutes of eating such foods.
Not all reactions are due to immune response. In some cases, the body may not have the enzymes responsible for digestion, causing intolerance to certain foods.
Many chronic problems of gut and digestion have been attributed to food intolerance, e.g., leaky gut, IBS, and indigestion.
Symptoms of food intolerance are rather mild. These include discomfort, mild stomachache, itchy skin, rashes, and headache. The symptoms take several days to appear and might be attributed to various other conditions. This makes diagnosis of intolerance to a given food very difficult. Because our diets include a wide variety of foods today, and they are resourced from around the world, pinpointing specific food to the problem can be extremely challenging.
While a food allergy test checks for IgE antibodies, food intolerance tests check for IgG and IgA antibodies.
In a standard test, antibodies produced against 96 common foods in our diets are reported. However, for thorough checkup, a comprehensive food sensitivity test might be necessary. With 208 foods, such a test covers almost everything in American diets including dairy, nuts, fish, poultry, fruits, vegetables, herbs, coffee and tea. Checking immunoglobulin G (IgG) levels is generally sufficient unless testing for IgA is necessary.
The critics of IgG food sensitivity test say the results can be compounded by other ongoing conditions. Therefore, our labs run the test in duplicate to ensure the results are repeatable and any outliers are cross-examined.
A diet rotation plan, that is designed based on the IgG food sensitivity test, is an excellent way to isolate suspect foods from your diet. The test makes recommendations on eating certain foods over a period of few days, and then repeat a few times. This approach is a popular way to confirm the results and to isolate the culprit foods in a diet.
Although eggs and dairy are some of the most commonly known suspect foods, people sometimes find trace amounts of herbs, nuts, seafoods, and other exotic ingredients as the root cause of their troubles. A diet rotation plan, based on a food sensitivity test, can be a great way to achieve the desired results.
Celiac, on the other hand, is almost entirely a genetic problem. The body often produces antibodies against gluten in people who carry the DQ2 and DQ8 genes.
Gluten is commonly found in wheat, barley, and rye—and in rare cases—a hybrid of wheat and rye called triticale.
In celiac disease, the immune system reacts to gluten, by producing antibodies against it. On prolonged exposure, the nutrient absorbing lining of small intestine is damaged. A biopsy to check this damage is one of the surest ways to confirm celiac disease. The low surface area from this damage to the intestinal lining, and subsequent lack of nutrient absorption, are the reasons behind indigestion and malnutrition in celiac patients.
Celiac is a global problem, although very few cases are fully diagnosed.
After reviewing the symptoms, next step in diagnosis is a celiac genetic test to confirm the presence of celiac genes. Although close to forty genes are now known, mainly DQ2 and DQ8 appear in confirmed cases.
A positive result is no guarantee to have celiac. Only about 4 in 100 people with the genes eventually test positive for the disease. It is not yet understood why most many positive cases show no signs of the disease and live a normal healthy life.
A negative result is very useful, because it is extremely rare to have gluten intolerance without the DQ2 and DQ8 genes.
As part of the five step serological testing, next step is a blood test to confirm the presence of antibodies. The celiac antibody test checks for enzyme tTG (tissue transglutaminase) and antibodies specific to DGP (deamidated gliadin peptide). A simple finger prick with few drops of blood might be sufficient for testing.
For those testing positive, biopsy of small intestine is important to confirm the diagnosis.
There is no cure for celiac. However, a careful regimen that strictly excludes gluten is the only way to live a normal healthy life. In recent years, such gluten-free diets have gained popularity. Increasing awareness is forcing suppliers to follow stricter controls to avoid contamination of common food items.
Contamination is much more prevalent than one would expect. For example, contamination of oats during processing is common and has given a common perception that oats also carry gluten. This is not true in a strict sense, although they are advised in limited amounts for celiac patients.
We might not be able to control what’s in our diets, but by carefully checking our sensitivities, it is possible to plan our diets around them to live a normal happy lifestyle.
Celiac – FAQs - key facts about gluten intolerance.
What is Celiac? History, Present and Genetic Risk - a detailed look at celiac.
Celiac Disease and Genetic Risk - a comprehensive review of the underlying genes.
A Brief History of Celiac Disease - a two thousand year old history.
A Brief History of Gluten-free Diet - from banana diet to today's popular GF diets.
Sensitivity to Food – Allergy, Intolerance, and Celiac Disease - a comprehensive review.
Food and Health: Allergies, Sensitivities, and Intolerances - learn the differences.
Food Allergies vs Food Sensitivities: What’s the Difference? - a few simple steps to differentiate.
Food Allergies and Gluten Intolerance - ways in which food can adversely affect us.