Zero tolerance

    31 May 2014

    There is an epidemic in parts of London that is in danger of engulfing communities, causing misery for schools, restaurateurs and doctors. Rumour has it that the situation started in Notting Hill and has now swept across Chelsea, Chiswick, Hampstead and Mayfair. Shoreditch and Clapham are at risk and early signs have been witnessed in Essex, Cheshire and Surrey. Soon enough the entire country will have been afflicted by food allergy or intolerance — and it’s no laughing matter.

    Allergies and intolerance are hugely complex, and in my 16 years of practice as a nutrition professional, few other topics cause as much impassioned debate and confusion. Yet according to Allergy UK, just 1.8 per cent of the adult population lives with a proven food allergy while food intolerance is thought to affect under 10 per cent of the population. So, given that avoiding foods day in and day out is stressful and fraught with problems, what has happened to make some 20 to 40 per cent of the adult population think that they are food-intolerant?

    In a true allergy, the immune system responds to exposure to the allergen with specific antibodies, immunoglobulin E, or IgE. This can result in swift and powerful inflammatory response typified by itching, vomiting, hives, swelling or anaphylaxis. A blood test will confirm the presence and number of these antibodies. If they are found, then a food allergy can be diagnosed. If they aren’t then it won’t.

    Nothing could be further removed from the robust black-or-white of a food allergy than food intolerance, which is entirely opaque. Instead of IgE, food intolerance involves a different antibody, IgG, which can take 24 to 48 hours to respond and leads to a wide range of symptoms. These can include fatigue, headaches, flatulence, poor memory, dark circles under the eyes or weight gain, all of which are potentially attributable elsewhere. To complicate things further, there is widespread disagreement about IgG. While some experts believe that an increased level denotes intolerance, just as many believe that levels rises naturally as a consequence of eating a food. In other words, have a chicken sandwich for lunch; draw blood at teatime and the antibodies for chicken and wheat will be raised. Had one eaten a salad niçoise instead then tuna, beans and black olives might be cited as culprits. Could the misreading of test results be linked to the staggering numbers of people who feel that they have, or been told that they have, food intolerance? Aside from blood tests, there are several as yet unproven methods of diagnosis, such as muscle testing or machines that measure ‘cell resonance’ or bioenergetics, all currently considered unreliable.

    In my clinical experience, someone who thinks that they have food intolerance can be very determined when it comes to getting confirmation. They often consult as many health professionals as it takes until they get a diagnosis, only satisfied when their suspicions are confirmed, sometimes via a test bought online, or a blood test taken at the wrong time. It’s big business too, as some labs charge around £300 — and that’s without the associated therapists’ fees. If a patient feels that they have been rebuffed by their GP, who might tell them that no intolerance exists, then you can see how they might be prepared to pay big bucks elsewhere and keep paying until someone says yes.

    It’s this grey area that is causing yet more problems, as trying to get a GP to order more tests when you are the third person that morning who feels they are bloated after eating a croissant is nigh on impossible. How many patients with true food allergies or intolerance are less visible as casual diagnosis outside the doctor’s surgery becomes the norm?

    ‘It’s an allergy’ has become shorthand for not liking or wanting something, but this simply trivialises true cases of intolerance and allergy. Added to this is the fashionable aspect of being food-intolerant. If you doubt this, then why else would such food sensitivities be far more common among celebs sitting on the front row compared with soldiers serving at the front? Until there is a standardised test then of course people will look elsewhere for guidance and keep looking until someone — anyone — will take them seriously and offer them practical help. If that means using quack-like tests and being guided by a well-meaning, yet totally unqualified, therapist from a dodgy doctrine, then so be it.

    The gold standard for managing food intolerance is a period of exclusion coupled with a detailed food diary noting every mouthful and subsequent health issues. This is a tedious exercise — and until there’s a better alternative, it’s almost understandable why claiming an allergy is an easier route.