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The Science behind Allergy

Multiple Chemical Sensitivity

Dr David L. J. Freed, MB, MD, MIBiol


You don’t need extra-sensory perception to know that our environment is heavily polluted with chemicals. Government watchdogs do their best to control the most toxic ones, but with only variable success. The chemicals, some quite poisonous, are building up inexorably year after year, in the air, the water and the food, in our own bodies and even in mothers’ milk. Industrial effluent, household products, and even prescribed medicines all add to the load. Not all of the hundreds of thousands of chemicals in the environment have been studied for toxicity, while their effects in combination have hardly begun to be thought about. The genie is well and truly out of the bottle, and there seems little prospect of pushing it back in (short of a comprehensive global nuclear war, which might create its own difficulties!)

But what’s the problem? Chemicals are good, aren’t they? Without modern chemicals there would be no motor transport, no computers, no aerosol cans, no plastics, no deodorants, no convenience foods (and not much fresh food either, since our farmers use agricultural chemicals to protect the crops from pests). Our whole lifestyle would have to slow down and millions of people would simply starve to death!

Well, all that is true. There are no easy ways out of the predicament. I’m a sinner as much as anyone – I also drive a car and I too use a computer, and when I go overseas I don’t insist on travelling by sailing ship. If you’ve got the money you can still get organic food and clean water, but why should you when most of us seem to be surviving, and indeed living longer and in greater luxury than ever before?

For most of us these concerns about chemical pollution are theoretical and rather distant from real life, but for some people they are immediate and life-ruining. From about the mid-70’s, in allergy practice in Manchester, I started seeing people who claimed to be ill with numerous symptoms affecting most of the body systems (including the mind and emotions), and asserting that their illness was caused by environmental chemical pollutants that the rest of us don’t even notice. Often they claimed to be “allergic” to foods as well. Physical examination and normal laboratory tests revealed few (if any) abnormalities and for many years we allergists didn’t really know what to make of it all. That was when the dreadful media title of “Total Allergy Syndrome” became current (allegedly coined by the Daily Mail). Doctors were in general hostile to the idea and some downright scornful, but there was no doubt in my mind that the patients were real enough, and their suffering was equally real, however subjective.

Allergists in America set up special “environment control units” (ECU’s) built of non-outgassing materials, where the air and water were filtered to remove chemical pollutants, and sufferers could find respite, however temporary, from the constant chemical deluge. Here the concept of the chemical challenge was born, which provided the first real science for this situation. Take a patient who thinks he or she is being made ill by tiny traces of chemicals. Put him/her in the ECU for a few days, consuming nothing except filtered water, until he/she claims to be feeling better. Put him/her into a sealed compartment, still breathing purified air, and place into the air supply of that compartment traces of the suspect chemical for five minutes, at levels that might be found in ordinary street air and too low to be detected by smell. After five minutes remove the chemical and flush the system through with plain purified air. Repeat the process every half-hour or so, not warning the patient when the “challenges” start or stop. Have the patient keep a diary, every five minutes, of what his/her symptoms are (if any), when they start and when they stop, then look to see whether the timing of the symptoms fits with the timing of the challenges (allowing a suitable delay for the effects to begin). Painstaking, time-consuming and expensive though these studies were, and not suitable for everyday use in the clinic, they nevertheless confirmed the existence of sensitivity in some patients to ambient levels of common chemical pollutants such as traffic fumes, domestic gas, pesticides etc. Some patients were genuinely sensitive to numerous chemicals and the term “Multiple Chemical Sensitivity” (MCS) was applied. Not every patient who thinks he/she has MCS has really got it, but in practice, if the history seems plausible, I generally proceed on the basis that it’s true. There was an excellent ECU in Yorkshire for some years, but it was forced out of business by bureaucracy so for the time being chemical challenges (and therefore accurate diagnoses) can only be achieved in the USA.

MCS is sometimes the result of an acute chemical exposure – a car accident perhaps, or a spill of cleaning fluid or sheep-dip, or being caught downwind of a farmer’s crop-spray. In these cases the mechanism seems to be poisoning of enzymes. What enzymes? Well, perhaps surprisingly, our planet was polluted with chemicals - natural chemicals - long before industrial times. Much of our food, especially vegetable foods, contain natural toxins such as alkaloids, lectins and enzyme inhibitors. Even the air we breathe is slowly poisoning us by oxidising our tissues. To stay alive in the toxic brew that we call this world, nature has endowed us with powerful enzymes in the tissues, particularly the lungs, gut and liver (the portals at which most of the toxins enter our bodies). These enzymes detoxify the toxins and allow us to delude ourselves that Nature is benign and that we are in charge of our lives. Those same enzymes (in health) handle artificial chemicals too, though not perhaps as efficiently, and that is how we survive. This has been the lot of all human beings for as long as there have been human beings.

But what if those enzymes are themselves poisoned, overwhelmed by some massive exposure event, or simply by a gradual buildup? That person, now a patient, will now no longer be able to detoxify the toxins, either natural or man-made, in the food, water or air, and will report intolerance (“allergy”) of foods and chemicals. Further chemical assaults will prevent the enzymes from ever recovering. Ashford and Miller termed this “toxin-induced loss of tolerance” (TILT – one of the numerous acronyms that litter the jargon of this condition).

Treatment consists of (a) stopping the relentless build-up of chemicals in the body, (b) ridding the body as far as possible of its toxic load (detox), (c) restoring the detoxifying enzymes to their former strength and if necessary (d) desensitising for any allergies. This is accomplished by lifestyle and dietary changes, optimising of nutritional status, mobilising toxic chemical stores from the body tissues (especially fat depots) by sweating and perhaps neutralisation, removal of amalgam fillings from the teeth etc etc. It is a delicate business because mobilised toxins can make the patient a lot worse in the short term and the process has to handled slowly and with great care. I tend rather to distrust the numerous “detox remedies” that one can buy at health-food shops, though I have no experience of them and some may be effective. Fortunately there are laboratory tests available nowadays to help us monitor the situation.

None of this solves the linked long-term problems of global ecology and global economy, but it offers an escape route (for the time being) for sufferers who can afford it. The whole area unfortunately still resides in what is popularly thought of as “alternative” or “complementary” medicine, especially since some sufferers are also sensitive to microwave and other electromagnetic waves (now there’s a real horror story!) Politicians and doctors – not to mention the industrialists who fund them – are reluctant to acknowledge the scope or even the existence of these problems. This panglossian attitude will of course have to change once the sheer number of sufferers forces the problem onto the international agenda. We can but hope that this will happen before it is too late for us all.

Recommended Reading:

Eaton KK, Anthony HM, Birtwistle S, Downing D, Freed DLJ, McLaren Howard J, Maberly DJ, Mansfield JR, Myhill S, Radcliffe M. Multiple chemical sensitivity: recognition and management. J Nutr Environ Med 2000, 10: 39-84.

Ashford, NA. Miller, CS. Chemical Exposures: Low Levels and High Stakes (2nd ed); Van Norstrand & Reinhold: New York, 1998. ISBN 0-442-02524-6

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