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Allergies and Intolerances – What’s The Difference?

The following extract from entitled Allergies and Intolerances – What’s the Difference? Is from David Reavely’s book, The Big Fat Mystery with kind permission from the publishers, John Blake Publishing – Metro Books; available on Amazon:

Not surprisingly, many people get confused over the difference between allergies and intolerances. Basically, an allergy occurs when the body becomes over-sensitive to a food or other substance. For instance, when we eat a food that we are sensitive to, the body over-reacts to its presence in the body. In simple terms, it is an exaggerated and misguided defensive reaction by the body’s immune system to something that is normally harmless. When this happens, the immune system produces ‘markers’ which identify substances that it doesn’t like. The proper name for these ‘markers’ are antibodies, of which there are several different types, namely, IgE, IgG, IgA, IgM and IgD. The primary antibody relating to so-called classic allergies, is the IgE antibody. When someone who has a classic food allergy ingests the food that they are sensitive to, the immune system responds in the following manner:

The offending food, known as an allergen, is eaten (e.g. wheat)

  1. The immune system is alerted to make IgE antibodies specific to that food.
  2. Millions of these IgE antibodies circulate in the blood and combine themselves to the specific food.
  3. The resulting IgE molecule then combines with mast cells which are embedded in the body’s solid tissues at sites such as the lining of the lungs, nasal passages and the walls of the intestines.
  4. The IgE molecule triggers the mast cell to release histamine and other chemicals that result in classical allergy symptoms such as gastrointestinal upsets, swollen throat, sinusitis, etc

If the allergen enters the body through the lungs (e.g. pollen) or is absorbed through the skin (e.g. printer’s ink) then this may result in the likes of skin rashes, asthma, hay fever, etc.

All of these reactions are immediate inflammatory reactions and are referred to as Type 1 allergic reactions.

In essence, people who experience allergic reactions are often well aware of what upsets them and therefore find it easy to identify the source of the problem.

Food Intolerances

Some reactions to food do not involve IgE antibodies. They are sometimes referred to as intolerances or sensitivities. In contrast to the quick reactions associated with allergies, the affects of an intolerance may manifest themselves a few hours later; or in some cases even a day or two later. This being the case, you can imagine that intolerances are much more difficult to discern compared to allergies. In fact, if you have more than one intolerance in the equation, it can be a bit of a nightmare trying to sort out which food is affecting you and which one isn’t. Some intolerances are the result of the body’s inability to digest the food in question; for instance, some people find it difficult to digest lactose (milk sugar) in milk. This is usually because they lack the lactose-digesting enzyme, lactase. In such a situation, if the lactase deficient person consumes milk, they experience uncomfortable digestive symptoms, such as bloating and indigestion. However, leaving this type of food intolerance aside, it is now thought that some delayed intolerances are associated with another kind of marker known as IgG antibodies. These antibodies also attach themselves to allergens, but only result in symptoms when they reach a certain level in the body. Experience as a Nutritional Practitioner has taught me that there are many people who suffer from environmental and food intolerances, including babies and children. Two of the most common intolerances that I encounter on a daily basis, are dairy and grain intolerances.  With regard to the latter, wheat intolerance is quite common, as is an intolerance to gluten, which is the protein component in wheat, barley, rye and oats. The more clients who tested positive for food intolerances over the years, the more I realised the diverse range of health problems that they can cause. I used to think that food intolerances mainly affected the digestive system resulting in symptoms such as bloating, indigestion, acid reflux, constipation and irritable bowel syndrome. Boy was I in for a big surprise!! It wasn’t very long before I realised that these conditions were just the tip of the ice-burg! For a start, clients didn’t always experience any digestive problems at all. Or if they did, they were also suffering from some other complaint, such as migraines, depression or a skin condition which they didn’t connect with their digestive problems. In essence, the range of conditions often included the following:

  • Eczema
  • Psoriasis
  • Migraines
  • Attention deficit disorder
  • Poor memory
  • Depression
  • Low energy
  • Bedwetting
  • Hay fever
  • Arthritis
  • Muscle aches
  • Menstrual problems
  • Sinus congestion
  • Rhinitis
  • Behavioural problems and hyperactivity in children
  • Mood swings
  • Erratic sleep patterns
  • Mouth ulcers
  • Weight gain

This list is far from exhaustive, and does not include digestive problems, which are sometimes, but not always present. What astounded me was the fact that quite a few of these people were being treated for their conditions with drugs, usually without any long-term success. This was not surprising considering that the underlying cause was not being identified; i.e. an intolerance to food, or more than one food.  Remember, this also included people who had been struggling to control their weight problems, sometimes over several years.

Frequently Asked Questions About Food Intolerances

Over the years I have been asked many questions about food intolerances. I have included some of the most frequently asked questions below:

Question: What is gluten?

Answer: It is a type of protein present in wheat, barley, rye and oats. This protein is made from two components – glutelin and gliadin. It is the gliadin component that people can become sensitive to.

Question: Why are so many people suffering from wheat and gluten intolerance these days?

Answer: I believe this is due to the amount of wheat (which is also highest in gluten) that most people consume in the West. Hence the term, the Western-style of diet. For example, think about the average office worker. He/she might have toast and cereal for breakfast. Mid-morning they might have a biscuit made from wheat. At lunch-time they might grab a sandwich because it’s quick and convenient. Mid-afternoon maybe they will eat another biscuit. During the evening they might eat a pizza, or have a pasta dish. Ok, this is an extreme example; however, it serves to illustrate just how prominent wheat features in the diet in European countries and the USA. It is because of this repeated exposure to wheat that people develop a sensitivity.

Question: I have an intolerance to wheat and diary foods. If I miss them out of my diet for long enough will I be able to re-introduce them in the future?

Answer: There is a greater chance of re-introducing an intolerant food compared to an allergic food. Often, if someone is allergic to a food, they must avoid it for life. For example, a person who is suffering from ceoliac disease (an allergy to gluten). However, food intolerances sometime do fade when you abstain from eating the offending food for long enough.

Question: I am doing well with my wheat-free diet, but I find it difficult when I’m out with my family and friends; especially when we eat out in a restaurant. Will it really matter if I have a little wheat on those occasions?

Answer: It depends upon the individual really. Some people might get away with eating a little wheat on the odd occasion. Nevertheless, if they continue to eat wheat on day two or three, even though it’s a small amount, they may then start to experience uncomfortable symptoms again. Others may react quite quickly after eating the wheat on that just one occasion. The same thing applies to all other foods that you may be intolerant towards.

Question: Why do so many people who suffer from a grain or dairy intolerance experience irritable bowel syndrome?

Answer: Because an intolerance to such foods causes irritation or inflammation to the lining of the digestive system. The body’s way of dealing with the irritant (food) is to evacuate it from the system as quickly as possible in order to minimise the length of time that the body is exposed to the allergen. When the offending food is omitted from the diet for long enough, the digestive system begins to heal and the IBS symptoms often diminish and disappear entirely. I have witnessed this on several occasions.

Question: When someone is tested positive for a food intolerance, is it absolutely necessary to exclude it from the diet 100%.

Answer: The short answer to that question is yes. To give you an example, I once advised someone who tested positive to wheat to exclude it from his diet for an initial period of four weeks so that we could evaluate the results. This person was suffering from bloating and indigestion but he had high hopes of curing his condition. For the first two weeks he noticed some big improvements. His indigestion and bloating disappeared and he lost eight pounds in weight. Needless to say he was delighted. Unfortunately, during the following two weeks he began to experience a return of his symptoms. I asked him to keep a food diary. This revealed that he had been eating the occasional biscuit during his morning break at work. This had been the ‘spanner in the works’ so to speak. He then missed out the biscuits and began to achieve the same positive results he’s experienced at the start of the programme.

Question: Before beginning my gluten-free diet, I was two stones overweight and seriously lacking in energy. I found that I would put on weight very easily and would watch my calorie intake. Despite this I couldn’t shift the extra weight. Since missing out the gluten-grains I have not only lost weight, but I also find that my apatite has improved and that I can eat larger quantities of foods without putting on weight. Why is this?

Answer: In addition to the fact that your body is no longer retaining excess water because you’ve avoided eating gluten; your digestion has become much more efficient since it is no longer hampered by gluten’s damaging effects.

Question: Don’t people who are intolerant to grains lack fibre in their diet?

Answer: Not if they are including the grains that they are allowed in whole grain form. Whole grains contain all of the goodness of the grain with nothing removed. For example brown rice contains lots of fibre compared to white rice which is seriously lacking in fibre. The same can be said of the other gluten-free grains in their whole grain form, such as buckwheat (no relation to wheat despite the name), quinoa (a south American grain), corn and millet. By consuming these grains you will be getting plenty of fibre in your diet.  Also, eating whole grains helps you to regulate your weight. This is because the carbohydrates that they contain are slowly converted to sugar (for energy) due to the presence of the fibre, which slows down the conversion process. The opposite is true with refined grains such as white rice.