Wednesday, March 5, 2014

Food Intolerance, What is Real and What is Not

It seems like everyone is gluten free these days. Is gluten bad for us? What about wheat and other grains? I’ve heard of food sensitivity blood tests…should I get tested? Every day I have 1 or 2 patients ask me these same questions. It is time to set the record straight…

Food intolerance is real. Foods that irritate your body and cannot be properly digested are a food intolerance. They range from person to person, with symptoms mild to severe. Nausea, stomach pain, diarrhea, vomiting, gas, bloating, cramps, heartburn, headache, irritability, and nervousness are the most common signs someone has a food insensitivity/intolerance.

Food allergies are not as common but symptoms can be similar. The largest difference is that food allergies involve the immune system and are life threatening. The body produces immunoglobulin E (IgE) which circulates throughout the blood and releases histamines once exposed to an allergen. People with allergies may begin to feel itchy, experience gi distress, or even have difficulty breathing. If you have a true food allergy, having a blood test will reveal IgE antibodies. It is very important for people with food allergies to avoid foods that they are allergic to.

Food intolerance does not involve the immune system and are not life threatening. People with food intolerance may need to avoid trigger food to prevent the unwanted symptoms they experience. There are many different food substances that cause intolerance; the most common are lactose, preservatives and additives, tyramine, and gluten. In recent years food sensitivity blood tests have surfaced claiming to identify food intolerance and help you avoid your trigger foods. 

Are food sensitivity blood tests valid?

Food sensitivity/intolerance tests seek out the presence of IgG and IgA antibodies to identify reactions to various foods. Some people who receive test results and eliminate identified foods do believe the test helped them. The American Academy of Allergy, Asthma, and Immunology’s position is that the tests do not have clinical relevance, are not validated, lack sufficient quality control, and should not be performed. These blood tests produce an unacceptably high false positive rate and are not accurate enough to diagnose food intolerance. Also the presence of IgG antibodies to foods may not necessarily mean intolerance but could be related to foods you eat often or ate recently. Research also shows elevated IgG antibodies have been related to childhood allergies that were outgrown as a child becomes an adult (such as an egg allergy), indicating increased tolerance to the food not an increased intolerance.

At this time the best method of identifying food intolerance is through an elimination diet. This diet removes foods and slowly reintroduces them one at a time over several weeks while keeping close track of your symptoms. A dietitian can help assist you with an elimination diet to help ensure your success.

The bottom line is food sensitivity testing may have worked for some people, but the evidence-based research backing up the findings are not there. If you have received test results and have eliminated foods based solely on this recommendation, you may try slowly adding back in these foods and see if you experience any side effects. If you are currently suffering from food intolerance and you do not know which foods are causing you distress, working with an allergist and dietitian and trying an elimination diet may help bring you relief.

What about gluten?  

Gluten is a protein found in wheat, rye, and barley responsible for triggering an immune response in about 1% of the American population who suffers from a condition called Celiac Disease. Symptoms include diarrhea, anemia, pain, skin rash, and malabsorption. People with Celiac Disease must avoid gluten to prevent nutritional deficiencies. Some people may suffer from an intolerance to gluten, which does not trigger an immune response, and avoiding foods with gluten may help them feel better.

Gluten is deemed safe to consume and there is no reason to avoid it unless you experience symptoms and avoiding gluten resolves your discomfort. Currently gluten-free products are booming and many people perceive a gluten-free lifestyle to be healthier-this is not always the case. Many whole grains that contain gluten are rich in vitamins, minerals, and fiber that gluten free products may be lacking. Also gluten free products may be higher in fat, sugar, and salt to improve taste. The bottom line is avoiding gluten does not make you any healthier than eating gluten. The majority of people tolerate gluten and it is safe to eat. Some people may experience intolerance and avoiding gluten helps relieve their symptoms. 

What about wheat and other grains?

Wheat is one of the most common allergies among children. It involves an immune response and production of antibodies after exposure to several different proteins found in wheat. With Celiac Disease only one protein, gluten, causes an immune response. Avoiding wheat is essential for people with wheat allergies, particularly hidden sources of wheat such as in condiments and beer. Intolerance to wheat and other grains does exist, and just like other intolerance's it does not trigger an immune response. Starting an elimination diet to pinpoint what specifically is causing your symptoms is the most effective way to manage food intolerance.

Food allergies and food intolerance can be difficult to manage. Working with your registered dietitian to find a well balanced diet that works for you can help. Grains are an excellent source of nutrients and energy; they belong in every healthy diet in moderation.

No comments:

Post a Comment