Allergy - Clash of Cultures – Professor Nick Read

Professor Read is Chair of the IBS Network

How is it that over 50% of people in this country complain of food allergy and intolerance yet medical tests establish the diagnosis in less than a tenth of them. Why are symptoms that seem to be exacerbated by food often labelled as functional or psychosomatic? How can elimination of specific foods such as milk from the diet seem to cure illnesses where there is no objective evidence of allergy or intolerance? Is this some kind of conspiracy? Have doctors just become so immured in their scientific criteria that they are not seeing the broad picture? Are patients now so fearful of food toxicity and contamination that just the thought of it makes them ill?

Food allergy exposes a real clash of cultures. Evidence based medicine insists that doctors have to establish a diagnosis objectively in order to justify specific treatment. Thus allergy is a specific immunological diagnosis and food intolerance requires objective biochemical criteria. Not everybody agrees with this perspective.

Allergy UK, in common with my copy of Chambers Dictionary, defines allergy as ‘an unnatural reaction to a natural substance’. So medically, allergy is a relatively rare condition, but from the perspective of the millions who suffer from food reactions, it is very common. Problems arise when people adopt the broad definition of allergy and then assume that it is supported by immunological evidence or when doctors fail to acknowledge that there are many reactions to food that cannot be validated by immunological tests.

In his article in February’s Inside Story, Dr Harry Morrow Brown states that ‘specialization has created barriers to the holistic approach which is essential for the recognition of the diverse illnesses caused by reactions to food and the environment’. He is, of course, correct. We desperately need to adopt a holistic approach if we are to understand food allergy and intolerance. But, from a holistic perspective, illness is the reaction of the whole person, mind, body and spirit, to his or her environment. It is more than just the body’s reaction to a specific food.

Many studies have indicated that most people suffering from allergy or intolerance have intolerances to a variety of different foods. In fact, a survey Joan Ransley and I carried out on patients with Irritable Bowel Syndrome several years ago, showed that every patient tested was intolerant to at least 5 different foods and 50% were intolerant to 22 of them! So this suggested that food allergy is not so much the cause of Irritable Bowel Syndrome, but that irritable guts are intolerant of food.

Physiological measurements have confirmed that the intestines of people with IBS are significantly more sensitive and reactive than those of healthy people. So just as somebody with sunburn finds it painful to put on his shirt, so somebody with a sensitised gut reacts to the presence of food, especially those foods that normally stimulate peristalsis or are fermented releasing large amounts of gas. The more sensitive intestines of IBS also respond more painfully to distension with a balloon and the sickening or gut wrenching emotions. People with IBS can be, quite literally, gutted. As a result, research in IBS has tended to focus, not on finding the specific food allergy, but on discovering what it is that makes the gut more sensitive.

The accumulated evidence suggests that sensitivity, anywhere in the body, can be caused either by local inflammation, or by the emotional tension induced by anxiety or indeed a combination of the two. We all know how emotional tension can bring on headaches or backaches, cause us to feel the urge to empty our bladder and make the pain of toothache unbearable. And many patients with painful conditions know how their pain can be relieved by relaxation and hypnosis. Sensory signals from the organs of the body are normally damped down in the spinal cord by suppressive nervous influences from the brain, otherwise we might be acutely conscious of the passage of food through the gut.

Most of us are not. Nevertheless the increased vigilance associated with anxiety inhibits that suppression, so that more of the signals reach consciousness as pain and also stimulate gut reactions. So excessive or unnatural reactions to components of our environment can be emotional as well as physiological. In fact, speaking holistically, our emotional responses are part of our personal immune system.

This might suggest that illnesses such as Irritable Bowel Syndrome are either all in the gut or all in the mind, rekindling the ferocious debates of recent years. The dichotomy, however, is a false one, because unnatural reactions to the environment often involve both types of response. Let me give you two examples. The first concerns the observation that in a relatively small percentage of people, an attack of gastroenteritis can be followed by chronic symptoms of IBS.

My research team wanted to know what it was that distinguished these from the patients who recovered completely. We found that those who went on to develop chronic bowel symptoms, were not only more anxious and depressed at the time of their original attack of food poisoning than those who recovered completely, but they had experienced more recent life changes. Thus although the infection had in fact recovered, it seemed as if the symptoms had, in some way, been recruited to express the unresolved emotional tension.

The second example gives some insight into how this might come about. Ellen MacQueen and John Bienenstock, two researchers in Canada made the intestines of rats allergic to a foreign protein by means of subcutaneous injection. Thereafter, whenever the researchers put the protein in the rats feed, they also rang a bell. After a few trials, the rats came to associate the ringing of the bell with the abdominal gripes and diarrhea, so that this reaction ecame ‘conditioned’ to the bell even when it was given without any food or protein.


The invasion of the gut by a foreign substance can stimulate an inflammatory reaction involving local mast cells. Mast cells are like tiny grenades in the gut wall. When stimulated they release a cocktail of highly potent chemical transmitters that trigger gut reactions, such as diarrhea, vomiting and pain in an attempt to get rid of the foreign substance and prevent any more from being eaten. Now when mast cells are stimulated they tend, like the broomsticks in the Sorcerer’s Apprentice, to proliferate into more mast cells setting up a chain reaction. They also tend to make connections with nerves, opening up a channel of communication between mind and gut. In this way the gut reaction, becomes a kind of warning beacon stimulated by anything associated with original infection or allergic response, and keeping the mast cell chain reaction going. So as long as the conditioning stimulus is maintained, the reaction continues.

Now we all know how the memory of particularly traumatic life events can cause our heart to race, make us feel faint, cause us to get a lump in our throat, make us feel sick and many other bodily reactions. What I am suggesting is that if a particular bodily reaction becomes established as the warning beacon by the mechanisms described above, then this illness responds to particular emotive memories and thoughts as well as the foods that may be associated with them. So food allergies may not always be specific immunological or biochemical reactions to particular food components, but reactions to the thought of the food. This might explain why some people with milk allergy react to milk but not to milk products, why medical tests may fail to reveal any objective evidence of infection or allergy, and why blinded experiments carried out in the 1950s showed patients with severe milk intolerance only developed symptoms if they were told that milk was injected into the stomach irrespective of whether that was true or not. The following case synopsis illustrates this in an especially poignant manner.

Amanda had ignored how late Rick was coming home and the increasing number of nights he had to spend out of town. Times were tough for both of them and she knew that Rick was taking on extra jobs so that they could get married and start a family. So when Rick suggested that they go out for a meal because there was something he had to say to her, she felt thrilled and excited. The venue was perfect; a little fish restaurant in a village a few miles away. Rick was attentive as usual but seemed somehow tense and sad. They chose the ‘salmon with prawns and that delicious buttery sauce' She had just finished hers when he blurted out that he had been having an affair with Margaret, who worked in the office. It had been going on for some time. He still loved her but he loved Margaret too, and well - somehow she had got pregnant. Amanda listened with mounting horror and dread. How could this be happening? Suddenly she couldn't stay there any more. She insisted that Rick drive her home, where she was seized with the most violent diarrhoea and vomiting, which continued for three days. Every time she even thought of food she would be sick.

That was three years ago. Rick left and married Margaret, but she lost the baby. Amanda moved to Doncaster, but she continued to be unwell. Subsequent to the attack of gastroenteritis on that fateful evening, she developed an ‘allergy’ to fish so that even the smell of fish made her violently ill. This spread to other foods and even an invitation out made her feel ill.

Amanda's gut reaction to Rick's catastrophic news had been so dramatic that anything that reminded her of that fateful evening made her feel sick. Her gut had been conditioned to the associations - going out on dates, nice meals, and particularly fish made her sick. Her doctor had sent her to a gastroenterologist - all the tests were negative. She had been to an allergist, who carried out tests and advised a very restricted diet. She was still no better, so in desperation, Amanda went to see a therapist and was able for the first time to talk about what had happened. Slowly, her symptoms improved and she gained in self confidence. Although she has remained very wary of eating fish, this no longer rules her life. The last I heard from her, she was married and had had a little boy.

Amanda was lucky. Talking through what had happened with somebody else had allowed the feelings of shame and anger that had been buried for so long to escape, so that they were no longer expressed through her body. So slowly this channel of communication slipped into the background and she was able to get on with her life.

It is not certain whether Amanda’s illness was instigated by a specific toxic reaction to the fish as well as the toxic reaction to her bad news. It may not have been. Such extreme emotional tension in the context of a meal could cause a surge in activity in the sympathetic and parasympathetic branches of the autonomic nervous system, causing the most profound gut reactions of pain, diarrhea and vomiting. It could also cause exaggerated immune responses to otherwise innocuous constituents of food and stimulate the mast cell cascade.

But I do not wish to imply that food allergy is all in the head, but neither can I accept that it is all in the body. Instead, I suggest that people with food intolerances do indeed have allergy in the widest holistic sense of the term – an exaggerated reaction of the whole individual to his or her environment. We are not divided at the neck. Whosoever we are, however we react is influenced by our environment as mediated by the way we think about it. So I would urge both orthodox and complementary practitioners to abandon the Cartesian dichotomy once and for all times and embrace the holistic nature of illness.

Perhaps I am merely restating the obvious. Reading again Dr Harry Morrow Brown’s excellent article, I am struck how many of the cases he described also had some difficulties in their life and I therefore wonder whether they responded as much to his ability to understand them holistically as to the specific elimination of milk.

The conviction that food is the cause of the symptoms is more likely to become consolidated when the emotional connection is difficult, painful and cannot be talked about.

Bringing the emotional link to mind through the medium of psychotherapy allowed one of my patients, Sheila, the opportunity to get rid of the symptoms by exploring the hidden emotional issues, but she was not entirely happy about things.

‘ For years, I was so careful about what I ate because I was convinced that my disease was caused by an allergy to food. At Christmas when I went home, I ate everything and didn't get any problems with my tummy at all. Now I've come back to the stress and problems of my life here, all the symptoms are back again and I'm watching what I eat. I guess it must be due to stress.‘

‘ But you're disappointed.’

‘ Yes, because I have no control over the stress.’


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