Life Extension Magazine®

What's Really Making You Sick?

Do you suffer from chronic “mystery” symptoms—headaches, digestive problems, or more severe conditions your doctor can’t explain? You’re not alone. An estimated 60% of all undiagnosed ailments are the result of food sensitivities. A cutting-edge blood test may now help you identify and eliminate the dietary factors behind your symptoms.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in August 2023. Written by: Lauren Russel, ND, and Jonathan V. Wright, MD.

What’s Really Making You Sick?

Do you regularly suffer from headaches, insomnia, stomach upset, constipation, or diarrhea—but can’t seem to get lasting relief? Have you gone from one doctor to another for nagging or painful “mystery” symptoms—only to find that none of them has been able to tell you exactly what’s wrong, much less come up with an effective treatment?

You’re not alone. It is estimated that anywhere from 45-60% of the general population struggles with an extraordinary range of symptoms whose causes can’t be readily identified.1, 2 You may be one of them.

Before you give up altogether, though, take heart: your health “problem” may not be the problem at all. In reality, your symptoms may be signs that something in your diet is making you feel sick.

Unfortunately, identifying which of the many foods you regularly consume may be causing your symptoms, or the specific natural or artificial compound contained in any of those foods, can be like trying to find a needle in a haystack. There are as many food allergies and sensitivities as there are symptoms. And until recently, the available detection methods have been rudimentary at best.

The good news is that advances in individualized blood testing now enable you and your doctor to zero in on the compounds causing your problem. With the results in hand, you can methodically and definitively eliminate them from your diet.

In this article, you will discover the multitude of health conditions that food sensitivities can cause. You will learn about the underlying mechanisms at the core of your body’s response to certain foods. You will also find out how a cutting-edge diagnostic test can help you uncover the cause (or causes) of nagging symptoms or painful conditions—and possibly make them disappear.

Food Sensitivities and Food Allergies: A Widely Overlooked Problem

Food allergies and sensitivities account for approximately 60% of all undiagnosed conditions, by some estimates.2,3 Any system of the body can be affected, resulting in one or many of the following health conditions:

  • Asthma
  • Bedwetting (enuresis)
  • Recurrent bladder infections
  • Recurrent bronchitis
  • Bursitis
  • Canker sores
  • Celiac disease
  • Chronic low back pain
  • Depression
  • Diarrhea
  • Childhood ear infection
  • Fatigue
  • Gas
  • Gastritis
  • Headache
  • Hives
  • Irritable bowel syndrome (IBS)
  • Itching
  • Learning disabilities
  • Personality changes
  • Recurrent infection (various)
  • Joint pain and swelling
  • Skin rash
  • Ulcerative colitis

And this is just a short list.

So it’s worth your while to step back and take a look at the foods you’re eating in order to improve your health and quality of life. As with pollen, dust, or pollutants, natural or introduced chemical compounds contained in foods can trigger an allergic response. We’ve all heard of someone who had to be rushed to the hospital because a restaurant used peanut oil in preparing certain dishes without informing its patrons.

Food Sensitivities and Food Allergies: A Widely Overlooked Problem

These are properly defined food allergies, and they manifest immediately. They may pose a more immediate health threat, but are relatively easy to detect and treat. Food sensitivities, on the other hand, are triggered by a distinct underlying mechanism. They can take a long time to develop, making them difficult to identify as the culprits behind a given set of secondary symptoms. The problem is they can wreak just as much havoc on your body over the long-term. Think of them as a food allergy in slow motion.

Here’s the difference between food allergies and sensitivities: once your immune system detects a substance it considers foreign, a chain reaction is set in motion to repel the perceived “invader.” This defensive mechanism is launched by lymphocytes, white blood cells capable of producing specific antibodies to target and neutralize the threat.

They release five different types of antibodies: IgA, IgD, IgE, IgG, and IgM. It is the IgE and IgG antibodies that are mobilized when lymphocytes come in contact with allergenic food proteins.4,5 We don’t know precisely what causes some people’s immune systems to consider foods to be “foreign,” while other people’s immune systems consider food to be—well, just food! However, in the process of trying to rid the body of something it believes shouldn’t be there, a vital and normal process goes very wrong, subjecting us to “symptom attacks” triggered by the foods we depend on every day for life.

Again, these types of intense reactions—anaphylactic reactions—occur within minutes after eating or being exposed to a food or other substance6 and are usually associated with “IgE” antibodies. IgE-mediated food allergies are most common in infants and children; we tend to lose sensitivity to many of these common food allergens as we age.7,8

“IgG”-mediated food sensitivities tend to be “masked” or hidden, since IgG antibody-related symptoms tend to occur many hours to days after exposure to offending foods.3 Considerable controversy exists about these types of food allergies and sensitivities, precisely because of the delayed onset of symptoms and the difficulty this presents in making a clinical correlation between symptoms and food triggers.

This is where accurate and reliable allergy testing has the most to contribute to diagnosis. The best support comes from research and from actual patients showing that, when foods suspected of causing adverse reactions are eliminated from the diet based upon sensitivity testing, symptoms improve. If the food is then added back into the diet, patients often report a return of symptoms, a pattern that suggests a strong correlation between the ingestion of the food and your body’s reaction.9

Sickness... Or Food Sensitivity?

A surprisingly broad array of health “problems” are in reality the result of these undetected food sensitivities. Perhaps the most well-known example of this is the widespread number of health problems produced by gluten (or gliadin, one of its constituents), proteins found in products made with wheat, rye, barley, and spelt (in fact, most grains except corn and rice). Though oats are not a gluten-containing grain, they tend to be included in this group because they are often processed on the same equipment as wheat and may be contaminated by it.

What You Need to Know: Food Sensitivities and Blood Diagnostics
  • Food Sensitivities and Blood Diagnostics
    An estimated 45-60% of the general population suffers from serious symptoms and health conditions whose causes cannot be readily identified.
  • Many of these “mystery” symptoms are attributable to an underlying food sensitivity, including headaches and migraines, insomnia, digestive disorders, and a multitude of stubborn health problems.
  • There are as many problematic foods as there are symptoms, and until recently, the available detection methodologies have been rudimentary at best.
  • An advanced, convenient, low-cost diagnostic technology called the FoodSafe™ test now enables you and your doctor to zero in on the potential food-related cause of your health problems and methodically eliminate them, providing optimal health and lifelong relief from your “mystery” symptoms.

The most serious form of gluten sensitivity, known as celiac disease, may affect as many as 1 out of every 133 people.10 If undetected and untreated, gluten sensitivity can cause a weakening of the villi of the small intestines. These minute, finger-like protuberances are vital to nutrient absorption; their atrophy may lead to a host of chronic ailments.11 Those who are sensitive to gluten can, at its worst, experience severe weight loss, fatigue, and malnutrition, all caused by nutritional malabsorption related to gluten. Of course, many if not most of these adverse effects can be prevented or reversed when gluten sensitivity is detected early and products containing gluten are eliminated from the diet.12-14

Though many theories have been proposed for its cause, irritable bowel syndrome (IBS) is another condition that may have its origins in food sensitivity.15,16 At any given time, 12-20% of adults complain of symptoms consistent with a diagnosis of IBS, making it one of the most common gastrointestinal disorders in the United States.17-19 The symptoms characteristic of IBS include gastrointestinal discomfort and pain accompanied by intermittent diarrhea and constipation. More women than men are affected. When patients are assessed for food sensitivity and those foods identified by testing are eliminated from the diet, many report significant improvement in their symptoms.16,20-25 In one study, improvement after specific food elimination was sustained a minimum of one year later for most participants.9

Migraine headache is another condition long associated with food sensitivity.26 Among the foodborne triggers most frequently associated with migraine are nitrates, a type of preservative found in certain types of processed meats; tyramines, which are found in red wine, cheese, and soy sauce; and phenylethylamine, found in chocolate.27 Caffeine, citrus, vinegar, and alcohol may also be migraine triggers. People suffering from migraines have been shown to improve significantly once they remove offending migraine “trigger foods” from their diet.3,28

IgG-mediated food sensitivities tend to be masked or hidden, since IgG antibody-related symptoms tend to occur many hours to days after exposure to offending foods.
Inconvenient and Expensive Test Methods

Inconvenient and Expensive Test Methods

Diagnosis of a food sensitivity depends on many things, including your previous medical history, comprehensive physical examination, oral food challenges, and results of laboratory testing.7,29,30 There are several types of laboratory tests designed to detect food allergies and sensitivities. One of the best known allergy tests measures for food-specific IgE antibodies using a skin prick test, in which the patient is exposed to a variety of foods scratched into the skin and observed for a local allergic reaction. Although fairly accurate for inhalant allergies, the positive predictive accuracy of skin prick tests for food allergens is less than 50% compared to double-blind, placebo-controlled food challenges.31

There are two types of skin testing that may be far more accurate, but they take considerably more time. Performed almost exclusively by physician-members of the American Academy of Environmental Medicine (, they’re termed “provocation-neutralization” and “serial dilution titration.” In addition to accurate testing, these techniques can help you identify and resolve your food sensitivity issues.

The “radioallergosorbent” test (RAST) and its successor, the “enzyme-linked immunoassay” (ELISA) are both blood tests used to detect food-specific IgE and/or IgG responses. Most commonly, food sensitivities are assessed using the ELISA test to detect IgG4 antibodies to food antigens, a subclass of IgG antibodies. Between 45 and 95 separate foods are measured. Accurate testing requires the patient to eat a wide range of foods within 3 weeks of assessment for IgG4 exposure to be present.

A Cutting-Edge Detection Method

Fortunately, an advance in diagnostic technology is now available that uses a very small amount of your blood to assess your sensitivity to 45 of the most common food antigens. Instead of requiring blood to be drawn from a vein, a small lancet is used to prick the finger so that a few drops of blood can be placed on a blood spot collection card. After the card is allowed to air dry, it is returned to the laboratory for assessment of IgG4 antibodies to food.

Known as the FoodSafe™ test, this is a simple and effective way for you and your doctor to detect the foods your body can’t handle. Each test report comes with a personalized profile showing how you tested against 45 foods most commonly associated with food sensitivities. The report indicates whether the levels of antibodies to the various foods suggest they are “safe” to eat, best to eat in moderation, or foods you should avoid entirely. Results are ranked and reported to you and your doctor as either safe or not safe.

After reviewing your test results, you may wonder what’s left for you to eat, since it’s not uncommon for many of the foods causing you the most trouble to be your favorite foods. Although each person’s plan may vary, more than likely your doctor will ask you to avoid the foods that are considered “unsafe” on your test results. Generally, this means going on an elimination diet for up to 30 days, during which time you avoid the foods that you are most reactive to in your profile. It’s a good idea to also avoid foods that are from the same “family” as those foods you are reactive to. For example, sensitivity to one kind of shellfish may mean that you should avoid other types of shellfish for a certain length of time. For this reason, your doctor may prescribe a diet that contains foods less likely to trigger reactions and allows your body and gastrointestinal tract time to recover from the continuous assault it has unknowingly experienced.

A Cutting-Edge Detection Method

Does this mean you will never be able to eat these foods again? The answer depends on your problem foods and your symptoms. Obviously, if your allergic reaction is life-threatening, you’ll be advised to permanently avoid that food. There are other reasons for life-long avoidance, too, such as gluten intolerance, which makes absorption of many nutrients difficult and good health impossible.

In other cases, you may be able to add a food back into your diet after a period of avoidance, as long as you eat it less frequently. One approach is to avoid the “reactive” foods for a period of time specified by your physician, typically 2 to 4 weeks, and then re-introduce these foods back into your diet to see if you respond to them.32

When avoiding foods during trial periods, eliminate even very small amounts! Reading food labels and understanding the many ways foods are listed as ingredients is important. By avoiding foods for this length of time, your body and immune system have time to recover, and you’ll have a more accurate idea about whether the food can be re-introduced or not, and if so, how often.

During the “challenge” (re-introduction) phase of the elimination diet trial, your doctor may ask you to re-introduce one food that you were reactive to once every 4 days to see if symptoms recur. If you don’t develop symptoms, then it may be possible to include the food in your diet, but less frequently. If symptoms do recur, then you may have to avoid the food for 6 months or longer.

Rotation diets have been shown to be very effective for treating food sensitivities in some people.33 On the rotation diet, a food is only eaten once every 4 days, allowing the body to clear it between exposures. The rotation diet helps you avoid too much exposure to any one food and gives you a better idea what foods are contributing to your symptoms, in case they recur. If you are more sensitive to certain foods or clear them more slowly from the body, you may need to eat them no more frequently than once every 7-10 days.

Your plan may also include taking omega-3 fatty acids to lessen inflammation, probiotics to replenish gastrointestinal flora, and other products like glutamine that promote intestinal healing.9,34-36 One of the primary benefits of food sensitivity testing is that your doctor can more easily customize your approach based upon your history and test results.


An estimated 45-60% of the general population suffers from serious symptoms and health conditions whose causes cannot be identified. Many of them have no idea that various forms of food sensitivity may be to blame. Reactions to food are the hidden cause behind an extraordinary array of health problems, including headaches and migraines, insomnia, and digestive disorders. An advanced, convenient diagnostic blood test technology called the FoodSafe™ test now enables you and your doctor to zero in on the potential foods behind your health problems and methodically eliminate them—for lifelong relief and optimal health.

If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.


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