I have seen an increasing number of patients over the past few years with food related health problems. Many of my patients have tried various types of elimination or similar diets; for example, gluten or dairy free, high or low protein, grain free, or raw/vegan with varying levels of success. Often, these patients end up in my office still wondering whether the food they’re eating is causing their health problem and not quite sure what to do about it.
In reality, most food problems people have are not actually allergies, even though we think of them that way. In truth, classic food allergy has very distinct symptoms—an immediate, severe type of response that can include swelling, shortness of breath and/or fainting and can potentially be fatal. It is also not that common—recent medical guidelines placed the incidence of true food allergies at only 2% of adults and 8% of children in Western countries.
On the other hand, food sensitivities or intolerances are more varied; they might appear within 30 minutes to an hour after eating a food or may take several hours or days to appear. Some of these food-related symptoms may in fact mimic conditions more commonly associated with environmental allergies; sinus congestion, headaches or asthma. They might be purely digestive: patients may complain of nausea, abdominal cramps and diarrhea. Further complicating the picture, one common characteristic is that symptoms may be triggered by a food at one occasion, but not consistently.
With food sensitivities, the food is often a commonly consumed part of the patient’s diet; here in North America frequently symptoms are triggered by gluten, eggs, dairy or soy. The initial triggering event may occur following a gastrointestinal (GI) infection, or a course of antibiotics, or by processes we don’t yet understand. Microscopically, what is happening is that the digestive immune system begins to recognize that food as an invader. Once that process begins, the food molecule is now ‘tagged’ with antibodies, which can travel through the bloodstream and be deposited into small vessels in the gut, lungs, nasal passages or other areas of the body, causing distressing symptoms or contributing to chronic health concerns.
With food intolerances, on the other hand, the problem is usually that the person lacks a digestive enzyme or microbe that can break down the larger food particles into the constituent fat, starch or protein molecules that can be absorbed into the bloodstream. The result is that on most occasions that food is eaten, the patient will experience gas, or bloating, reflux, or similar symptoms, usually about thirty minutes to two hours after eating that food.
We do lab testing frequently in our office for food sensitivities. This helps guide elimination diets, which in turn help us decide if food issues are involved in that patient’s health condition(s). Depending on which foods show up as positive, and how many foods show up as positive, it also gives us a better idea of how well the immune system recognizes food proteins as harmless, and not ‘tag’ commonly eaten foods as invaders.
If there is a known trigger food that doesn’t show up on testing, there could likely be an enzyme problem or intolerance. This is especially true if a parent or other family member has the same problem, or if the patient is undergoing a period of significant stress. That being said, sometimes people with what appear to be clear symptoms have negative test results that are not related to enzyme problems.
This is where we rely on good clinical history and symptom patterns to eliminate foods that might be ‘likely suspects’. A few weeks of elimination and then a controlled challenge of the food—giving a reasonable quantity over a few days and watching for symptoms—will often clarify the picture for us.
With most adverse food reactions, however, an important point to remember is that eliminating foods often does not completely solve the health problem. The reason for this is that many food reactions are in fact a messenger for the breakdown of proper immune balance and tolerance. As research is increasingly telling us, the real problem is a combination of inflammation, poor immunity and loss of microbial diversity.
At this point, many people might be thinking—‘what do microbes have to do with digestion and our immune system’? As far back as infancy, we learn to tolerate foods as our digestive and immune systems develop and mature. This process is supported by gradually increasing numbers of friendly bacteria that line our digestive tract from top to bottom—what is known collectively as our microbiota. We inherit many of these microbes from our mothers: during pregnancy and childbirth, via breastfeeding, and from touch. Others we gain from coming into contact with these friendly bacteria in food, water and people in our surroundings. Collectively, our immune system develops along with this ecosystem of microbes as it has for thousands of years.
What has been happening since the era of antibiotics in the mid 20th century, however, is that we are exposed to repeated courses of these medicines, and also in our meat, dairy and poultry. This has lead to a situation were we are losing the diversity of microbial species along our digestive tract and on our skin. As a result, while we have far less infectious disease in developed countries, we also have increasing incidence of chronic illnesses such as eczema, hay fever, asthma, autism, diabetes, celiac and Crohn’s disease. Scientists and many doctors are starting to make the connection between this loss of microbial diversity, food adverse reactions, and the incidence of these allergic-type illnesses, suggesting that there is a link between healthy gut microbiota, orderly digestion of our food, and a balanced immune system.
The current generation of children is now the grandchildren—or the great grand children—of the children who were given the first antibiotics in the 1940s and 50s.While various theories have been put forward to explain this, recent studies are now telling us that delaying food introductions, or exposing children to backyard soils or pets–basically the hygiene hypothesis–doesn’t stop or even slow down the increased incidence of allergic and immune conditions. Instead, what children appear to need is more of their own ‘friendly’ bacteria; from breast milk, high fiber and fermented foods. Frequently I suggest adding a good, high quality probiotic to tip the balance in the right direction. Just as important, however, is to stay away from sanitizers and antibiotics for routine colds and flus, and consider natural alternatives for symptom relief.
After understanding these relationships, it seems clearer that foods themselves, if grown without pesticides or genetic modification, and eaten in moderation, are not the cause of food-related symptoms per se. The problem is instead a loss of balance in the immune system, where the system begins to overreact to food proteins, instead of to invading bacteria and viruses. Our goal in elimination diets then, should be to eventually restore a healthy and varied diet by restoring a full spectrum of gut microbes, and healing the damage that losing this varied microbial ecosystem has caused.
For more information see:
Blaser, M. Missing Microbes: how the overuse of antibiotics is fueling our modern plagues. Harper Collins, 2014.
Waltner-Toews D. Food, Sex and Salmonella: Why Our Food Is Making Us Sick. Greystone Books, 2008.
Zutavern A et al. Timing of Solid Food Introduction in Relation to Eczema, Asthma, Allergic Rhinitis, and Food and Inhalant Sensitization at the Age of 6 Years: Results From the Prospective Birth Cohort Study LISA Pediatrics Vol 121, no1 Jan 2008.
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