Dr Nigel Abraham Ph.D, MSc, FIBMS

Interview with the Director of Science and Laboratory Research at Cambridge Nutritional Sciences


Food intolerances: the hidden epidemic of modern times

We live in a time when we commonly encounter sick people or people who are tired, without energy and have various problems. What does this have to dowith and does it need to be addressed? I think that broken health is an essential reason why we should try to find out the cause of our problems and constantly educate ourselves. Because if a person lacks knowledge, many times he cannot help or make his life easier. Many doctors or experts already know that we can look for the cause of most diseases in our digestion. If you suffer from leaky gut syndrome, migraines, digestive problems, or suspect an overgrowth of Candida in your body, pay attention to the following lines. The hidden cause of a range of adverse symptoms may be food intolerances. I asked Dr Nigel Abraham, one of the UK's most experienced and well-known experts in functional medicine, who lectures on food allergy and intolerance, salivary hormones, digestive tract pathology and microbiology, about the difference between allergy and intolerance, the reasons for the condition and the experience of everyday people with the FoodPrint® test, which can detect food intolerances in humans.

Dr. Abraham, I would like to start by thanking you for taking the time to introduce our readers to the issue of food intolerances and to bring us more information about the FoodPrint® test for diagnosing food intolerances. So my first question is, who invented the FoodPrint® test and when was it introduced into medical practice?

Diagnosis of intolerant foods by the IgG specific antibody test was established more than 20 years ago and millions of tests have been performed by laboratories around the world since then. This test uses a technology known as ELISA (Enzyme Linked Immunosorbent Assay), which is a standard laboratory technique for measuring antibodies in the blood. The FoodPrint® test is a unique variation of this technique, created by Cambridge Nutritional Sciences using Microarray technology in 2011.

In your opinion, can it be considered reliable in the management of health problems and should it be part of routine investigative procedures?

There are many potential causes of food intolerance, some not involving the immune system per se, such as lactose intolerance, which is caused by a deficiency of the enzyme lactase needed to break down the lactose in dairy products, or histamine intolerance, for example, where the problem is a lack of activity of the enzyme diaminoxidase (DAO) needed to break down histamine, causing allergic manifestations.

Other types of food intolerance can be the result of the body reacting badly to certain foods. Those foods that are often part of our diet, or those foods that we crave, can cause us problems. Research has shown that these types of food intolerance may be related to the presence of specific IgG antibodies produced after eating the 'problem' foods. Normally these antibodies have no adverse effects, but if the immune or digestive system is not working optimally, their presence can cause a wide range of symptoms.

These types of latent (IgG) food reactions are often referred to as 'food intolerances' and are primarily the result of lifestyle and dietary habits, estimated to affect around 20-40% of adults at some time in their lives, often leading to delayed reactions that appear after a few days. This is why it is so difficult to spot a problem food.

This type of testing is not routinely available in public health facilities because these types of reactions are relatively mild compared to food allergy and rarely threaten the life of the patient, but can have a significant impact on the lives and health of many people.

Could you briefly explain the principle on which testing works and what the results are in practice?

FoodPrint® is a laboratory-developed system, founded by Cambridge Nutritional Sciences, that uses innovative microchip-based ELISA colorimetric technology to measure the amount of specific IgG antibodies in human serum or plasma. Blood is drawn from the finger. Food extracts are printed on intracellulose slides on the microscope slide along with calibration standards and controls.

The blood sample provided by the patient is diluted and split on each printed microarray. If specific IgG antibodies are present in the blood, they are bound to the food extracts and the results are measured with a high-resolution scanner before calibration against standards using FoodPrint® reporting software to obtain quantitative results.

The software then prints the result of the final amount of IgG antibodies against each food being monitored. Due to the innovative microarray format, it only takes a small drop of blood to test over 220 different food components in duplicate to ensure the accuracy of the results.

The results are intended as reports on reactive foods. With these results, professionals can work with patients to eliminate food intolerances and create a plan to eliminate problem foods, offer healthy alternatives, as well as provide guidance on how to incorporate problem foods back into the diet. In most cases, the recommended diet will be suggested to the patient for a period of approximately three months to allow symptoms to subside and the body time to recover.

How does the Food Print® test differ from other food hypersensitivity tests (such as the ImmunoCAP ISAC® test) used by most allergists and immunologists in Slovakia or the Czech Republic?

The most important thing to say is that the ImmunoCAP ISAC® test is based on microchips and is used to identify true allergies by measuring the levels of different antibodies called IgE. A food allergy is very different from a food intolerance and the results of the two tests should not and cannot be compared. In the case of a food allergy, the IgE antibodies produced can lead to the development of severe or even fatal reactions in a different way to that of a food intolerance. IgE food allergies are relatively rare, affecting an estimated 5% of children and 2% of adults, are largely influenced by genetic factors and manifest themselves immediately. Importantly, if symptoms indicate a potential food allergy, it is necessary to undergo this test to identify allergenic foods that should be avoided for the rest of one's life. If this test is negative and symptoms are more delayed, a blood test that measures IgG antibodies to the food should be considered.

Characteristics of reactions to food caused by the presence of IgE and IgG

Allergy caused by the presence of IgE

Intolerance caused by the presence of IgG

the incidence is relatively low

the incidence is relatively high

due to infrequent exposure

as a result of frequent exposure

common in children, rare in adults

the most common form of reaction in food intolerance in both children and adults

very predictable short-term symptoms

chronic, variable symptoms

problem foods are usually obvious

the problem food is often difficult to identify

reactions induced by basophilic granulocytes/ mast cells

immune complex trigger

histamine/leukotriene release

inflammatory reaction

the patient is aware of problem foods

the patient is rarely aware of problem foods

antibodies are present for years

the amount of antibodies decreases over several months

in vitro testing of specific IgE antibodies in the blood

in vitro testing of specific IgG antibodies in the blood demonstrates problem foods and the degree of intestinal permeability

lifelong avoidance of problem foods & immunotherapy

eliminate and later replace foods, heal the intestines, improve digestion

Food intolerances are not food allergies, rather they are conditions that can cause symptoms lasting for a long period of time. The slow development of food sensitivities often means that there is no obvious link between the foods eaten and the symptoms, making it very difficult or impossible to identify the foods that are causing the person problems. This makes food intolerances very different from food allergies, where reactions are usually immediately apparent and easily diagnosed. By the same token, a person may have an allergy to a food, but since different antibodies are measured for food intolerances, this does not mean that the allergy will show up in a food intolerance test. This is another reason why the two tests cannot be compared.

What do you think causes people to develop food intolerances over the course of their lives?

Normally, the gut and immune system are in balance and our body produces low amounts of specific IgG antibodies when we eat foods, which we call tolerance. Several factors have been identified that can upset this delicate balance, leading to a temporary loss of tolerance, including:

  • antibiotics
  • medicines
  • Candida overgrowth
  • parasites
  • inflammation of the intestine
  • vitamin D deficiency
  • glutamine deficiency
  • alcohol
  • poorly varied diet
  • stress
  • low stomach acid
  • low amount of pancreatic enzymes

The presence of these factors can lead to increased permeability of the lining of the intestine, which is often referred to as leaky gut syndrome.

Under normal circumstances (see Figure 1), the cells lining the walls of the intestine are tightly packed together, protecting against the penetration of potential pathogens, toxins and food molecules into the blood, which can lead to abnormal immune responses.


Figure 1. Normal intestinal permeability

When these tight junctions open under the influence of even small amounts of these factors, partially digested food particles can penetrate them, resulting in the activation of the immune system, leading to low-grade inflammation (see Figure 2).


Figure 2. Abnormal intestinal permeability

This condition involves the production of high levels of specific IgG antibodies against foods and the formation of immune complexes, which are highly inflammatory molecules that the human body is unable to neutralize (see Figure 3).


Figure 3. Damaged tissue shedding inflammatory cells

These immune complexes enter the bloodstream and lodge in tissues and organs, leading to symptoms associated with this type of intolerance, such as bloating, diarrhoea/constipation, intestinal pain, migraine and fatigue.

Under what medical conditions or symptoms would you suggest this type of testing to a patient?

I would recommend it to those people who exhibit any of the following chronic adverse symptoms:

  • irritable bowel syndrome
  • constipation
  • diarrhoea
  • bloating
  • stomach cramps, abdominal pain
  • migraine
  • headaches
  • fatigue and lack of energy

There are many more symptoms reported in published studies that may be related to food sensitivities, but the symptoms above are the most commonly reported.

Do you have experience that after several years of dieting according to the results of the Food Print® test, the patient's health improved? Is there a chance that the patient could return to a normal diet and recover from food intolerances?

The efficacy of a diet based on the results of measuring the specific IgG antibody class for individual food components has been demonstrated for a number of conditions, both in independent studies and in clinical practice. Excellent results have been demonstrated in patients with migraine, irritable bowel syndrome and obesity. A diet based on the results of testing for a specific class of IgG antibodies has been shown to be an alternative and safe treatment for patients with a variety of chronic conditions. Thousands of patients have been tested by the Cambridge Nutritional Science testing laboratory working with nutritionists. The vast majority of patients report positive responses after problem foods are removed from the diet and symptoms are alleviated. Unlike allergies, they don't have to avoid positive foods for life. It is generally recommended to avoid the most positive foods for a period of 3 to 6 months. In many cases, this is enough to regain tolerance and the patient can reintroduce problem foods into the diet under the guidance of a professional.

Could you advise us on how to make up for missing nutrients due to the absence of certain foods and suggest some alternatives? How could one prevent weight loss, nutritional imbalances or poor dietary choices?

It is important that any changes to the diet set according to the test results are made under the guidance of a specialist nutrition advisor, to ensure the correct nutritional balance using healthy alternatives. Reintroducing foods back into the diet should also be done under professional guidance.

Do you have experience with cases of overgrowth of Candida in the body or leaky gut syndrome that could be related to food intolerances? Has changing the diet helped people suffering from these conditions?

If the intestinal microflora becomes imbalanced, Candida albicans can change its form from small dormant spores, which are a normal part of the intestinal microflora, to pathogenic fungal forms that can stick to the intestinal wall. Damage to the intestinal wall allows toxins, including intact food molecules, to enter the bloodstream. This condition is called leaky gut syndrome. This leads to further inflammation of the intestinal wall, causing symptoms associated with food sensitivities. For patients who want to achieve long-term health, it is essential to identify food intolerances if they suspect an overgrowth of Candida in the body. A diet aimed at destroying Candida with low refined sugars has been shown to be more effective in alleviating symptoms. Antifungal treatment with the drug Nystatin is then recommended.

What about casein intolerance? Is it a valid indicator that one should avoid milk for life? Or will people be able to consume milk again after a break of several years?

Adverse reactions to dairy can be caused by different types of reactions and different tests would be needed to identify them.

Primarily, this could be due to lactose intolerance caused by a lack of the enzyme lactase, which leads to an inability to break down milk sugars effectively. This condition can be confirmed or refuted by genetic tests or breath tests, which look for the presence of excess hydrogen and methane in the patient's breath after consuming lactose. Although there are examples of acquired lactose intolerance due to damage to the gut, it is generally a hereditary condition and dairy products would have to be excluded or the use of enzyme supplements would be required.

Secondly, it could be due to a milk allergy, in which case tests for the presence of antibodies to cow's milk proteins of the IgE type or skin tests would be required. This is a long-term condition that requires strict avoidance of milk and milk-containing products.

Finally, it could be due to milk intolerance or milk sensitivity, which is indicated by high levels of IgG antibodies to milk and milk products. Since it is possible to regain tolerance after 3 to 6 months of milk avoidance, milk can be reintroduced into the diet in most cases.

What do you think about wheat or rye intolerance? Could it be related to current wheat processing or pesticide use?

There is evidence that 'modern' wheat may be more reactive than its older forms. For example, durum wheat has 28 chromosomes in contrast to other forms of industrial wheat, which have 42 chromosomes. It therefore has a very different composition to conventional wheat and contains different proteins. Our experience has shown that it is possible to react to wheat and not to durum wheat, and vice versa, but we recommend avoiding the consumption of durum wheat or consuming it with caution if a person shows increased sensitivity to durum wheat. The food allergens we prepare for testing are thoroughly purified. Any pesticide residues should not be present in the final result, which means that if there were any reactions due to the presence of chemicals on the surface of the wheat, they would not cause any reaction in our test. Although there is published evidence to suggest that some pesticides found in our food chain may have harmful effects on humans, there is little evidence to suggest that they may have an effect on food intolerances.

I have heard of cases of people who have been diagnosed with intolerances to more than half of the food ingredients tested by this test. What advice would you give to these people?

When the intestine is partially damaged or inflamed, it is possible that positive reactions to many foods will be noted. In this case, it is not advisable or possible to avoid all of these foods. It is advisable to concentrate on the most reactive foods. We recommend that the patient try to completely avoid the 4 or 5 foods that show the highest antibody concentrations, and then reduce and/or rotate out the remaining foods showing moderate antibody concentrations, while working with the practitioner to promote the health of his/her gut.

What does it mean for a person to have food intolerances? Does he or she have to avoid the foods in question, or is it enough to take the missing enzymes? Please explain the terms "sensitivity" and "intolerance".

The terms 'food allergy', 'food intolerance' and 'food sensitivity' are often used interchangeably and are confusing, but basically they all mean an abnormal reaction to certain foods, which can manifest itself in different ways. It may be the result of mechanisms that involve activation of the immune system and subsequent production of antibodies, or it may be a reaction that is not caused by an immune disorder.

In the case of immune deficiency, it is recommended to avoid the most positive foods for a period of 3-6 months, and then in most cases they can be reintroduced into the diet.

Food intolerance resulting from enzyme deficiencies will require either avoidance of the intolerant food group or the use of dietary supplements containing enzymes.





-IgE Antibodies
-IgG Antibodies

-Lack of enzymes
-Chemical effect
-Pharmacological effect


Who would you recommend the Food Print® test to and what would you like to say to our readers?

The FoodPrint® test is an important part of investigating the possible cause of a range of symptoms. If other medical tests, such as those for food allergies and other forms of intolerance, prove negative, using an IgG test to identify reactive foods in order to create a personalised diet for the patient is a highly effective and safe method to alleviate unwanted symptoms in many people.

Published studies have also shown an association between the presence of high levels of IgG antibodies to food and the development of low-grade inflammation. This type of inflammation is a proven risk factor for the development of cardiovascular disease and type 2 diabetes, and requires further research to determine how we can support the health and well-being of the patient, even when they have no obvious signs and symptoms.

The author of the article is Lucia Bartková