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Food allergies get all the press – but food intolerances tend to fly beneath our health radar, compromising quality of life.

On any given day, a health practitioner might see patients suffering from a variety of different and seemingly unrelated symptoms, such as fatigue, skin breakouts, bloating, sinus congestion, weight gain, headaches and digestive problems. Interestingly, this diverse range of health issues may in fact have just one key cause – food intolerances.

Most people are aware of the dramatic and sometimes life-threatening symptoms of food allergies, but few of us understand the potential health impact of food intolerances. Like food allergies, food intolerances are becoming increasingly common; however, the thing that makes food intolerances more problematic is that symptoms can often take days to appear, long after the food has been eaten. This makes it incredibly difficult to pinpoint reactive foods, which is why most sufferers don't realise that their symptoms are actually caused by food intolerance.

Intolerance or allergy?

Although both reactions can be caused by the immune system, food intolerances are very different from food allergies. According to the World Allergy Organisation, an estimated 220-250 million people around the world suffer from food allergies. Food allergy reactions are caused by the activation of IgE antibodies, which are predominantly found on the skin and in the lining of the nose, mouth, airways, and lungs. Common allergens include peanuts, eggs, tree nuts (Brazil and cashew nuts), and shellfish. Symptoms of food allergies develop rapidly and may lead to anaphylactic shock, becoming life-threatening.

Food intolerances, on the other hand, have several different causes, including a genetic lack of enzymes needed to break down particular foods (as in the case of lactose intolerance) or the body’s inability to absorb certain food constituents (in the case of fructose malabsorption). People may also react to other food constituents, such as amines (found in chocolate, cheese and red wine) or salicylates (found in some fruits and vegetables). Intolerance to food additives such as artificial colours and flavours is very common and is associated with behavioural problems in children.

The immune system can play an important role in food intolerances. Both IgG and IgA reactions are common causes of food intolerances; these immune-mediated reactions can lead to a slow onset of diverse symptoms, making it very difficult to identify reactive foods. Both food allergies and immune-mediated (IgG and IgA) food intolerances rely on the activation of specialised antibodies, which are produced by white blood cells in response to foreign bodies entering our system. These symptoms are basically our body’s way of trying to neutralise an invader.

Common culprits

Interestingly, the two main factors governing the development of immune-mediated food intolerances are the amount of a particular food eaten and its ability to stimulate an antibody reaction. As with food allergies, the most common culprits are wheat, gluten, cow’s milk, eggs, and yeast. These foods are extremely common in the Western diet and can be difficult to avoid if you eat any processed or pre-packaged foods. (Note that gluten intolerance is very different from coeliac disease, which is an autoimmune disorder.) One of the many benefits of identifying these common irritant and reactive foods is that, in order to avoid them, sufferers switch to a wholefoods diet to avoid processed foods. Not only do they find relief from the intolerance symptoms, but their overall nutrition improves.

There are two main approaches to identifying reactive foods: an elimination diet and immune-mediated food intolerance testing. An elimination diet can be a very effective strategy, but it may take several months to complete and can be testing for even the most disciplined person. Reactions to certain foods can also be delayed and rely on the amount of food eaten, so it can be difficult to clearly identify reactive foods. People can also react to individual compounds found in a broad range of foods, not just one food, which further clouds the picture.

Pathology testing, on the other hand, investigates your immune system’s reaction to common foods via a simple blood test. The benefit of this approach is that you are screened for a broad range of foods and receive a clear understanding of which ones you are reacting to. Your health practitioner can prescribe pathology testing through companies such as Healthscope Pathology. The only downside of this approach is that it can’t measure food intolerances associated with other causes. The fastest and most accurate approach is probably a combination of the two methods. Immune-mediated food intolerance testing clearly identifies which foods you are reacting to, and, if you continue to have symptoms after an elimination diet period of three months, you can experiment with eliminating other commonly reactive foods that don’t fall into the immune-mediated category, like food additives and amines.

The ‘leaky gut’ connection

‘Leaky gut’ is used to describe a state of hyper-permeability of the delicate mucous membranes of the digestive tract. Several factors contribute to this condition, including stress, poor diet, nutritional deficiencies, and some medications. Leaky gut is also associated with dysbiosis, which is an imbalance of the normal bacteria found in the digestive tract where chemicals given off by gut bacteria irritate the digestive tract lining, contributing to increased permeability.

The immune system acts as the body’s border patrol, waiting just outside the gut wall and guarding against invading pathogens. However, in the case of leaky gut, food particles pass through hyper-permeable mucous membranes before they are properly broken down, causing the immune system to launch an attack to rid the body of a foreign invader. Not only does this immune attack cause symptoms associated with food intolerance but it also increases gut wall permeability. Over time, the immune system becomes programmed to react every time it comes into contact with that food.

As leaky gut and food intolerances go hand in hand, both must be addressed at the same time. Ideally, once reactive foods have been identified they need to be eliminated from the diet for a period of time. Foods that cause a strong reaction on IgG testing need to be avoided for at least three to six months before a reintroduction can be trialled. This needs to be done carefully: foods are reintroduced one at a time and symptoms are recorded in a food diary. If no symptoms are present after four days the next food can be reintroduced. In some cases, strongly reactive foods may need to be avoided for even longer.

During the elimination period the leaky gut and dysbiosis must also be addressed. This usually involves treatment with antimicrobial herbs such as Chinese wormwood, barberry and black walnut, followed by reinoculation of the gut with healthy probiotic bacteria and nutrients like glutamine and zinc to support gut repair. Your naturopath or nutritionist will be able to help you get the best results.

Case study: Stuart Cooke

Father of three and owner of online health and wellness company 180nutrition, Stuart Cooke, 41, has always been passionate about health and nutrition. But when he started experiencing a range of seemingly unrelated problems, including bloating, sinus congestion, skin breakouts and difficulty sleeping, he was at a loss to understand why. A friend suggested that food might be the problem, so he went to see his naturopath who ordered an IgG food intolerance test*. The result came as a complete surprise: his body was reacting to a range of foods, including gluten, dairy, eggs, and some nuts.

“I had always suspected that wheat and dairy were a problem for me, so I had avoided them anyway. However, the real surprise for me was eggs,” says Cooke. “I had always prioritised good quality lean protein in my diet to help support muscle development, and eggs were a big part of that. However, I then cut them out completely. Since eliminating eggs and the other reactive foods I have noticed a significant difference in my health. My sinuses are clearer, my skin is better and I have had improvements in my health all round.” Cooke has been working with his naturopath to improve his gut function and will start reintroducing foods in time.

* If you are interested in food intolerance testing, your healthcare practitioner will be able to organise testing and advise you on an elimination diet.

Are you intolerant?

If you think food intolerances are signalled by an upset tummy or bloating, think again: in fact, all of these symptoms can be due to a food-mediated reaction.
* Anxiety
* Arthritis
* Asthma
* Bloating
* Chronic fatigue syndrome
* Constipation
* Depression
* Diarrhoea
* Difficulty concentrating
* Fatigue
* Fibromyalgia
* Fluid retention
* Gastritis
* Headaches
* Indigestion
* Inflammatory bowel disease
* Insomnia
* Irritable bowel syndrome
* Lethargy
* Malabsorption
* Migraines
* Mood swings
* Sinus congestion/post nasal drip
* Sleep disturbances
* Skin conditions, e.g. acne, rashes, eczema
* Weight control problems

Tania Flack is a leading naturopath and nutritionist with a special interest in hormonal and reproductive health and immune system support. www.taniaflack.com