Many people get confused by food allergies vs. food sensitivities and intolerances. An allergic reaction is just one type of reaction to food (or medications, environmental factors, pets, etc.), but there are many different types of reactions due to sensitivities and intolerances as well.
Traditional food allergies create antibodies in the body called immunoglobulin E antibodies (IgE antibodies), but food sensitivities result in IgG antibodies – testing for these two antibodies is different and often confusing. IgE symptoms (“allergic reactions”) are typically quick onset and obvious – hives, rashes, wheezing, sneezing, or more serious anaphylactic-type reactions. IgG (food sensitivity) reactions can be similar to allergies, but may also include behavioral or developmental symptoms, and these reactions are typically slower in their onset – sometimes up to three days after eating a certain food – making them harder to pinpoint.
Food intolerances are not immunoglobulin reactions, though. Food intolerances are issues with digestion of certain foods due to the lack of specific enzymes in the gut, most commonly affecting digestion of proteins from gluten, casein and soy. Celiac gluten intolerance; however, is an auto-immunue response from gluten exposure that damages the intestinal tract.
Intolerances may also include the inability to metabolize a certain component of a food such as phenols and salicylates. For example, lactose intolerances may cause immediate cramping and diarrhea; and gluten/celiac type reactions may be sudden (stomach pain, cramps, diarrhea) or long term reactions like neurological symptoms, fatigue, skin conditions, etc. With phenols and salicylates some reactions could be quick (red ears or face, hives, headaches, hyperactivity) or delayed (dark circles under the eyes, sleep issues, head banging, tics or repetitive movements, just to name a few).
For a more in depth list of food reactions and behaviors view this symptom checklist.
CAUSES OF FOOD REACTIONS
When food begins to digest in the small intestine it breaks down into its smaller components (proteins–>amino acids, fats–>fatty acids, carbohydrates–>simple sugars). Along with nutrients, these smaller components cross the intestinal lining (gut wall) into the blood stream where they travel throughout the body, and even into the brain. This is where the blood/brain barrier and “gut” come into play. The intestinal lining provides a barrier to block foods from entering the blood until they are fully digested and broken down. It’s like a sand sifter, only letting the smallest proteins through once they are broken down, keeping the larger/undigested proteins out. BUT when the gut or intestinal lining is damaged or “leaky,” larger, potentially harmful, food molecules can get through and enter the blood stream.
Many people with Autism, ADHD or auto-immune issues have “leaky gut.” There may not be enough digestive enzymes in the body to break down the food adequately or it may not be released when needed during digestion. Digestive enzymes act to break down protein amino acid chains into individual amino acids. The amino acids are absorbed through the intestinal lining into the body and then reform into peptides and proteins again to be used throughout the body. If the amino acid chains are not completely digested or broken down these peptides can leak through the gut causing the body to recognize them as foreign invaders so to speak.
I’ve heard it described as this…amino acids are like Scrabble letters and peptides are like the words made up of those letters. Depending on how you arrange the amino acids (letters) different peptides (words) are formed. But if the letters don’t form a real word, the body considers it foreign. Once through the gut, these “words” can send signals to the brain that are abnormal and this is where some of the symptoms of Autism and ADHD show up.
When certain peptides (words) get through the gut, and are arranged in a certain way, they can look like opiates and act on the brain in a similar way. Casein and gluten are the most common foods that cause opiate-like reactions on the brains of people with leaky gut. Gluten and casein contain sequences of amino acids, within their own chains, that resemble opiate-like peptides. When gluten and casein are not properly broken down (due to digestive enzyme deficiencies), specific amino acid sequences called gliadorphin and casomorphon can leak through the intestinal lining and go to the brain causing the opiate-like effects.
These opiate-like peptides mimic the effects of opioid drugs on the brain and can cause brain fog, giggling fits, night waking, high pain thresholds and many other symptoms.
*For us, reading this one bit of information triggered the lights to go on! Chase used to wake in the middle of the night uncontrollably laughing, almost as if he were drunk or high. The madder we would get at him, the more he would laugh. It was infuriating and frustrating! He was completely zoned out, didn’t respond to his name hardly at all, and he never seemed to cry in pain whenever he hurt himself. It was as if he didn’t have feeling or pain receptors anywhere. Reading these effects of gluten and dairy were the thing that made us reconsider a GFCFSF diet again. And with time, after removing gluten, casein and soy, all these things went away!
Like I said before, testing for food allergies vs. food sensitivities/intolerances can be tricky. Traditional allergists will test for true food allergies (IgE), with skin or blood testing, looking for immediate and fast-acting immune responses. However, this type of testing is not adequate when testing for IgG sensitivities and reactions related to leaky gut. In our experience, most allergists are not familiar with IgG testing; therefore making it more difficult to do. Most IgG testing is done through blood tests, not often covered by insurance, and typically through integrative or naturopathic practitioners.
For more information on food sensitivities/intolerances and phenols/salicylates click here.