The Health Writer’s Little Book of Food Facts... EverythingEverything youyou everever neededneeded to knowknow about dietary allergies and intolerance Amanda Bradbury Contents Pages 3 and 4 Foreword Page 5 What is food intolerance? Page 7 Food intolerance checklist Page 9 Main causes of food intolerance Page 15 Conditions caused by food intolerance Page 19 Tests for food intolerance Page 24 Food intolerance Q and As Page 29 What is food allergy? Page 30 How do GPs handle suspected cases? Page 31 Hospital tests for food allergies Page 32 Allergy key facts Page 33 Testing Q and As Page 35 Preventing food allergies in children Page 36 Controversial tests for food allergies Page 37 Hypersensitivity disease Page 39 Useful contacts Page 41 Clinical papers Muriel Simmons Foreword by Chief executive of the medical awareness charity, Allergy UK “Potentially millions of British men, women and children go through life with imperfect health because their dietary choices are causing symptoms they simply donʼt – or canʼt - connect with the food on their plate. While immediate onset food allergies are starting to be better understood, the delayed symptoms characterising food intolerance remain more mysterious, under-reported by the media, and dismissed, even within the medical profession itself. Yet experts believe that while true food allergy is still relatively rare (although showing a worrying increase) – food intolerance is more common and proving to have quite an impact on daily life. Often due to a lack of knowledge or time from healthcare professionals, sufferers frequently donʼt receive the treatment they need to manage their condition. Inevitably this forces the sufferer to turn to one of the host of alternative practitioners who all claim to treat and in some cases, ”cure” food intolerances. In my opinion, many of these treatments are questionable, and in a number of instances, simply do not work.” 3 Amanda Bradbury FForewordoreword by Ex-health and beauty editor of the Mirror M magazine “I reckon the average health editorʼs postbag would be practically empty if doctors had an answer for these fi ve problems: cravings, headaches, bloating, fatigue and weight gain – often blamed wholesale on ʻfood intoleranceʼ. But the challenge when any journalist writes about any these Big Five is not only saying something new, but also dealing with our own cynicism. Are these just trendy diseases of the worried well, an excuse perhaps to cut out dairy, just like your favourite popstar? Rewarding our readers with scientifi c facts that donʼt contradict something you wrote last month seems an impossible task sometimes. Yet for most of the medical profession the delayed symptoms of food allergy is unproven and mostly all in the mind. With this confusing background, no wonder many sufferers try their own versions of elimination diets and hope for the best. They are convinced that itʼs food that is causing their health problems, and new research shows that many of them are probably right. In this booklet, I have tried to outline accepted - and controversial - thinking on food intolerance and defi ne the difference between it and food allergy. Weʼll also discover why adverse reactions to foods are increasing and what are scientifi cally proven tests and treatments and which have not yet been clinically assessed but appear to give good results. I also give contact details for the leading British help groups and US, Euro and UK experts on this fi eld. There are clearly defi ned differences between types of reactions to food. In this booklet, I will use the term food allergy to describe the so-called “type one true allergy” involving immediate onset symptoms; and food intolerance for any other symptoms. These terms are used interchangeably by others – adding to the confusion!” 4 What is Food Intolerance? What is... food sensitivity/intolerance? A fi fth of us think we have food intolerance. A whopping 21% of British adults and children nationally complain of problems caused only by certain foods, according to a study published in The Lancet (A population study of food intolerance, Young E, Stoneham MD, Petruckevitch A, Barton J, Rona R, May 7 1994). In a further study published in the BMJ in 1999 (Psychological effects of starvation interpreted as food allergy in an English town, BMJ, July 31 1999) it was shown that of these, only around 1% of adult and 4% of child patients complaining of a food allergy tested positive for the IgE-type antibodies carried in blood - the calling card of a true allergy. The study group – all from High Wycombe - were tested using a double blind food challenge test where they swallowed opaque capsules of the suspect food hidden among other samples while researchers watched for a reaction. Later, blood samples are taken and tested for antibodies to allergens. This supposedly proved that in most cases, there was no immunological reason for the symptoms the patients interpreted as food intolerance. The authors dismissed these peopleʼs fears out of hand. They were being led on by the press (of course) and complementary practitioners to take matters into their own hands when there was really nothing wrong with them. But what if these people had been tested for a delayed, rather than immediate immune reaction? 5 Intolerance? What is Food New research, by the University Hospital of South Manchester, shows that symptoms of food intolerance could involve an immune reaction – but it is delayed for up to several days and therefore is unlikely to be picked up by a food challenge test. So could some or all of the study subjects, reporting symptoms like diarrhoea, sickness, bloating and tiredness, have been imagining their food intolerance? According to James Braly, senior medical editor of Food Allergy & Nutrition Update, the American immunology expert who introduced licensed allergy tests there in the 80s, food intolerance is “rarely accurately self-diagnosed”, but that scientifi cally based testing and professional advice specifi cally for the delayed symptoms of food intolerance is vital to resolve symptoms. 6 What’s the difference between food intolerance and allergy? James Braly pinpoints severalseveral keykey differencesdifferences betweenbetween allergyallergy and intolerance – including: • Immediate food allergy involves rarely eaten foods • Food intolerance is usually experienced with every day foods • Immediate reactions primarily affect the skin, airways and digestive tract (all organs of elimination) • In food intolerance, any tissue, organ or part of the body can be affected. In his book “Food Allergy Relief”, £7.99 (available from www.yorktest.com), Dr Braly says “Delayed onset food intolerance is linked to over one hundred medical conditions involving every part of the body”. Nutritional advisor Liz Tucker, author of “When you want to say yes and your body says no”, (£9.99, HarperCollins) also points out that one of the biggest pointers that someone may suffer from food intolerance is when they suffer from a chronic condition which appears to be untreatable. “These can be as diverse as cystitis, endometrial pain and depression. “Food intolerance involves a more delayed immune response than those involved in immediate allergies which usually requires continuing irritation (by eating the food often) to develop into symptoms.” 7 Allergy or intolerance? Intolerance Allergy It’s getting worse as I get older It comes on after less than an hour If I’m careful I can have a bit of the food I’m sensitive to It always makes me ill even if I don’t know I am eating it 8 Why does... food intolerance happen in some people and not in others? There are four main reasons why food intolerance can developdevelop – thethe fi rstrst is ... 1. Food intolerance can result if we don’t digest food properly It can be caused by the lack of or inadequate production of a specifi c digestive enzyme. The two most commonly problematic foods affected by enzymes are: Lactose is a natural sugar found in all milk from mammals and the enzyme humans make to digest it is called, confusingly, ʻlactase”. Insuffi cient quantities of lactase can result in people having lactose intolerance. More lactase is produced in humans under the age of two, but white Europeans – except some of Jewish origin - produce it into adulthood. For this reason, lactose intolerance is more common in other ethic groups – around 75% in black Africans and 90% in Asians according to the Food Standards Agency. Symptoms are stomach cramps and bloating and sometimes diarrhoea. But itʼs not known how many people suffer from it because small quantities of dairy products may not affect the sufferer. Casein (cowʼs milk protein) is the main reason why milk allergy is the most common allergen in childhood - up to 7% of British children are affected – though they could also be sensitive to whey in unpasteurised milk. Along with gluten, casein intolerance has been linked by some researchers with autism. A 2002 study by Massachusetts General Hospital and Harvard University in Boston, US, found that 50% of autistic children have problems with digesting particular foods, most commonly casein and gluten. Symptoms are more serious than those of lactose intolerance and include rashes, diarrhoea, stomach cramps and sickness and occasionally anaphylaxis. 9 Less common intolerances affected by digestive enzymes are: Sulphur dioxide and sulphites – preservatives in dried fruit, soft drinks and sprayed fresh fruit often contain traces of sulphur. Sulphur dioxide gas from the stomach results in throat irritation and wheezing. Low levels of sulphite oxidase, the enzyme which helps us process sulphur, is to blame. Fructose (fruit sugar) – the enzyme affecting this is called fructose-1 phosphate aldolase – and a genetic lack of this enzyme will result in sugar collecting in the liver, kidney and small intestine leading to severe stomach pain and vomiting.