ALIMENTS INTOLERANCE: WHEN FOOD ISN’T YOUR FRIEND

 

But what exactly is food intolerance, how does it manifest itself and is it possible to overcome it?

Food intolerance or hypersensitivity is caused by the organism's inability to metabolise or fully exploit certain types of foods. We must differentiate between food intolerance and food allergy. Whilst the latter is caused by a malfunction of the immune system and reacts immediately and violently to certain foods (for example an anaphylactic reaction to nuts in subjects allergic to it) causing illness and in most extreme cases even death, intolerances are less severe and are generally enzymatic reactions (a reaction to certain types of protein) to foods, although in some cases they can be of pharmacological or toxicological nature (hypersensitivity to substances contained in medicines or toxins and additives). Intolerances are milder than allergies and generally present discomfort rather than sudden malaise. The most common ones are lactose intolerance and coeliac disease.

Intolerances can be caused by many different factors. A diet containing too much or too little of a certain type of food, a prolonged course of antibiotics or other medicines, stress and lifestyle are all possible causes. 

It's not easy to establish the presence of food intolerances, mainly because the symptoms (diarrhoea, bloating, constipation headaches and migraines, sore throat, anxiety, depression, mood swings, itching, skin irritation, fainting, low blood pressure, arrhythmia to name a few) are often attributed to other types of illnesses and reactions to specific foods are not instant and violent, unlike in the case of food allergies, making it difficult to pinpoint exactly what the foods the immune system is reacting badly to are. 

Intolerances can present themselves at different stages in life. For example lactose and gluten intolerances are very common in children, but tend to disappear with age. Any type of food can cause intolerance, from nuts, to seafood to herbs. 

According to the World Health Organization 1-3% of adults in the world suffer from food intolerances. However according to many experts the number is far greater than that but since most people don't know that the cause of their ill-health could be related to nutrition, they attribute their malaise to other causes without looking at their diet. 

There are several different tests on the market that can be taken to establish the presence of food intolerance in a subject. I decided to take the Foodscan 113, courtesy of YorkTest Laboratories UK, because they utilise the most reliable one, the ELISA (Enzyme-Linked Immunosorbent Assay), a biochemical method that checks the presence of antibodies and antigens (macromolecules that react with the immune system) in the blood. ELISA is also used in toxicology tests and to determine the presence of antibodies in HIV tests.

The test in itself couldn't be easier: YorkTest sent me a blood test kit. With the small sterile needle included I pricked my thumb and used a pipette to soak up a few drops of my blood. After sealing, I sent my sample back to the lab, where they'd check it against a wide range of aliments. The results are classified on a scale of 0 to 4, where 0 means no reaction and 4 is a high one. A couple of weeks later I received my results back. The foods I'd already suspected being the cause of my symptoms – namely yeast and milk – did indeed come up as aliments I'm intolerant to, however the full list was much longer than expected. Now I was facing the prospect of going for a minimum of three months (the suggested time to follow an elimination regime, where the offending foods are removed from one's diet) without: all dairy products, all products containing yeast (think bread, wine, tofu and standard stock cubes), egg yolk, blackcurrant, pineapple, peanuts, walnuts, chilli, cinnamon, clove, coriander, cumin, dill, nutmeg, peppercorn, parsley, sesame seeds, vanilla, cocoa bean, coffee, sunflower seeds, tea and cola nut. I also had to go without lime, Brazil nuts and mustard seeds. Despite these three foods causing me borderline hypersensitivity (at around the 1-2 mark) it was still important that'd I'd consume less of them than usual and eventually none of them at all.
My first reaction at seeing the test results was almost tears. How could I go without so many foods? I can take or leave egg, blackcurrant, pineapple and milk, but wine, cheese, tofu, coffee, dill and peppercorn? This was going to be hard, but if I wanted to feel better there was only one thing to do: eliminate these foods and see if my health improved. Thankfully YorkTest Laboratories have a team of nutritionists that can help with the elimination diet and advise on food replacements, which helped enormously. As I embarked on my quest for optimum health I decided to ask a few questions to Dr Gillian Hart, biochemist and YorkTest Laboratories UK Scientific Director.

What are the benefits of eliminating foods one's intolerant to from one's diet?

By removing those foods from your diet you give your body a rest. You can remove the problem that causes the intolerance. There is a growing amount of literature – and I've written several review papers and articles about it – and the evidence shows that if people remove the foods they react to from their diet, those people will show improvement to their ill-health symptoms.
Are there foods in particular that are more likely to cause intolerance?

There are some foods that people tend to be more intolerant to, but what we've seen with people who come to YorkTest with symptoms of intolerance is that on average people have combinations of six different foods. What we have found in these studies is the combination of foods that is important, not just individual foods. Quite often when people are doing an elimination diet they are told to start eliminating one food at a time. We found that it's more beneficial to look at the combination of foods.

So there aren't specific combinations of foods that people are allergic to.

Not really. We do find several cases of people reacting to milk or wheat but rarely on their own. If you only remove one type of food, you still react to the other ones you are intolerant to, so you still have ill-health symptoms. It's not like an allergy, where you react to a specific IgE antibody. IgG antibodies instead have a delayed reaction, that's why is very difficult to say exactly what is causing these symptoms.
Do you think that people are more likely to go straight to their GP when they suffer from these symptoms of discomfort, without also looking at their food consumption? Is that changing?

I hope it's changing. We did a survey last year which showed that people are really dissatisfied with the advice they get from their GP because it involves medication. Our survey shows that on average, before people come to YorkTest, they've spent between £350 and £500 on medicines to try and ease their symptoms and they don't feel they are getting the help they need from their GP. In England GPs are not often trained in nutrition, so wouldn't tend to give patients dietary advice. Patients may get prescribed a steroid cream for eczema for example. Diet doesn't really come into the conversation when people go to their GP. 

When I joined YorkTest in 2005 I took the food intolerance test and although I didn't have any ill-health symptoms I knew that when I ate ice-cream I didn't feel very comfortable. (The test showed that) my reaction to milk was huge. I had about 3 or 4 reactions (to other foods) but they weren't strong. With milk it was particularly strong. Since then I've not drunk any cow's milk. Although then I didn't feel that ill actually, I feel so much better now, I feel less tired and less bloated.

I think people look at lots of other aspects if they feel unwell, but rarely at what they eat.

Yes. And also if you have a particularly stressful lifestyle….sometimes intolerance is part of the jigsaw.
75% of your immune system is based in your gut. If you have stress there as well you are going to feel pretty rough.

There are several food intolerance tests around, but yours is based on the very efficient Elisa system.

One of the reasons why our test is endorsed by Allergy UK is because we have clinical evidence to support it. There are other tests on the market but they don't have clinical evidence. At YorkTest we also provide nutritional support as part of the test. We feel responsible towards people removing foods from their diets. You don't want them to suffer from malnutrition.

How long should one do the food elimination diet for?

If you have many food intolerances you should eliminate the highest first. Although I talked about the combinations, you've got to be practical about it. The foods with the highest intolerance scores are more likely to cause symptoms. It's a question of trial and error. We find that if you remove these foods for 3 to 6 months you can then start to re-introduce them into your diet. Allergy is for life but with food intolerance if you eliminate certain foods and let your gut heal – you can help it by taking probiotics – you can tolerate those foods again after 3-6 months of removal. Management is down to the individual as well, everybody is unique.

Lastly, do you think that there has been an increase in food intolerance in the last few years?

Yes I do. It seems that these days people have more intolerances than they did in our grandparents' times. I think there are many factors that contribute to it. Starting with soil for example: over management, intense farming, fertilisers and polluters. Preservatives and additives are key too, like the ones contained in bread. There are so many things that go into the gut now, and then of course a stressful lifestyle. I think there are a lot of factors that contribute to making one's gut weaker and allowing food proteins to leak into it causing intolerance.
After two months of following the elimination diet I can honestly say I feel fantastic. Migraines have gone, bloating, itching and swelling are all in the past. It's not been easy, especially when going around friends' for dinner and I've also had the occasional cup of coffee, but the rewards have been immense. If only I'd done this a few years ago I would have saved myself a lot of discomfort, days off sick and the constant paranoia posed by the question: what's wrong with me? Would I advise anybody to take an intolerance test? Yes, if you are unwell and can't pinpoint why, looking at your diet is a very important place to start. 

Dr Gill Hart has over 20 years experience in diagnostic test product development from concept through to market. After completing a PhD in Biochemistry, Gill worked as Senior Biochemist at Hammersmith Hospital. From 1990 to 1999 Gill worked for Anagen Ltd (Alfa Biotech) in the development of automated immunoassays and was directly responsible for bringing to market 16 different diagnostic test products cleared for sale through the stringent FDA 510k regulatory process. In 1999 Gill set up DP Project Management and Consulting to service the needs of the IVD Medical Devices industry. Gill provided advice to many clients within the diagnostics industry, and the related regulatory environment.

Gill joined YORKTEST in 2005, and has applied her scientific and regulatory knowledge to ensure that all YORKTEST testing services have been fully validated; including putting in measures of ‘self-regulation' in the unregulated ‘diagnostic testing services' industry.

The YorkTest First Step Food Intolerance Test is currently available at the special price of £9.99 (RRP: £20.00) and YorkTest Foodscan113 Food Intolerance Test costs £265 or £245 if upgrading from the YorkTest First Step Food Intolerance Test. Available from www.yorktest.com or by calling 0800 074 6185.

by Stef Bottinelli