Allergies and Intolerances to Food  

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Finding a good herbalist

Most of what's written in this article is entirely suitable for a person to work through themselves but, especially if things are quite bad, or you just know that you need further help, then there may be a great deal of benefit to you to go to whatever lengths necessary to find a good herbalist or truly holistic practitioner to guide you on to a safe and strong treatment program. There's a short write-up to suggest how you might go about finding such a person here

Allergy vs. Intolerance

Both allergies and intolerances clearly affect many people and it has often been seen that the turning point in a person's health is when they remove those foods from their diet that were doing them harm.

Firstly, it is important to understand the difference between an allergy and intolerance because, whilst allergy gets almost all the attention in conventional medicine, many chronic health problems are more deeply connected to intolerances.



An ‘allergy’ is what happens when contact with a substance causes large amounts of histamine and other inflammatory chemicals to be quickly, sometimes violently, released.

Allergies manifest so quickly because the immune system thinks there is a toxic invasion taking place and tries to get rid of the substance as quickly as possible. Swelling, coughing, scratching etc. are all attempts to try to push the substance away as quickly as possible.

In extreme allergies, a person can have what is called an ‘anaphylactic reaction’ where their mouth and throat swell to the point that they have trouble breathing. In such emergencies, an adrenaline injection may be needed to prevent catastrophic consequences. Antihistamine drugs are usually recommended for less severe allergies.


'Intolerances' equally involve the immune system, and in many ways are just as much an 'allergic' reaction, but the crucial differences are the cells that are involved and the time factor.

Allergies primarily involve white blood cells called IgE cells, whereas intolerances are primarily mediated through IgG cells.

The activation of IgG cells causes a slower inflammatory process to take place. They are mostly caused by reactions to food and can take many hours to start to show symptoms compared to as little as minutes, or even seconds, for a classical allergy.

Intolerances are also much harder to diagnose than allergies. You may be highly intolerant to milk, or gluten, to use two most common examples, but skin prick tests and conventional IgE blood tests may tell you that you have no allergy to these substances whatsoever.

Intolerances are often a root cause behind both eczema and asthma. They are also often involved in other health problems that involve the immune system or where there is chronic inflammation in the body.


How are allergies & intolerances diagnosed?

The skin-prick method

Many people with health problems that look like they might be caused by 'allergies' will receive a skin prick test. This is very helpful for identifying the immediate, classical IgE allergy type reactions as described above because the skin immediately swells when exposed to a tiny amount of the suspected 'allergen'. The degree of swelling then gives a rough indication as to how strong the allergy is.

Unfortunately, and perhaps because these skin-prick tests usually include some foods along with pollens, dust-mites etc. many people think that if they or their children have had one of these tests then they are all clear and it must be something else that is the problem.

The skin-prick method does not help with diagnosing food intolerances, not at all. They can only tell you what you are allergic to, not what you may be intolerant to.

The elimination and challenge diet

The gold standard method of diagnosing food intolerance is the elimination and challenge diet. This is whereby you completely exclude the suspected food or foods for 7-10 days and then re-introduce the food or foods that have been avoided, nothing changes in your symptoms both off and on the foods.

Dairy products and Gluten-containing foods are the most common sources of food intolerance and, for many people, it will be appropriate and beneficial to trial an elimination and challenge diet with one or both to see what happens. Practical instructions on the 'how-to' of this are linked below.


Testing for allergies & intolerances

There are a number of alternative methods in the health market said to be able to diagnose food allergies and intolerances. They all look authentic and reliable but the truth is that most of them are bad; based on shonky science or no science at all.

Some common examples of this include the ‘blood group diet’, 'saliva-testing', and 'hair-testing' but you simply cannot accurately or scientifically diagnose food allergy or intolerance using hair or saliva samples.

You need to be careful in this area because; aside from losing your time and money, there is a real danger in being wrongly advised because by an inaccurate method. If you do such a test, or follow a diet plan based on something like your blood group, they all inevitably tell you that you are allergic to a number of different foods and this is where some real harm can be done.

What happens in this kind of testing is that everyone shows reactions to dairy or gluten or both and, because at least some of the people getting tested genuinely do have an intolerance to at least one of them, they get some significant improvements from avoiding them and go on to recommend the test to everyone they know with any health troubles. However, in the meanwhile, there are 10 or 20 other perfectly ok foods that have also registered as bad that they feel they must equally avoid.

Not only can this set the stage for a overly restricted diet but it can cause a great deal of long-term stress as it leads to a person struggling to navigate through life with a list of prohibited foods that are in fact perfectly okay for them to eat. In this area, it is crucial to find the truth and not be deceived by pseudo-scientific tests.

Aside from the elimination and challenge diet as described above, the only testing process for food intolerances that have any credibility are blood tests that pick up IgG intolerances.

Unfortunately, most routine blood testing does not include this though you can ask your Doctor if they are able to order IgG tests for you as an increasing number of laboratories do offer this service.

For some years now our clinic has been using the IgG blood test from Cambridge Nutritional Services in England. These tests are quite expensive but they have proven to be highly accurate and have been of great help in those cases where more than a simple dairy or gluten intolerance is involved.

Just to be clear, we have zero financial connection to this business, but in many parts of the world you can order a test from them directly that you can do at home by looking up Cambridge Nutritional Services online (

People are understandably daunted at the idea of doing a blood test by themselves but their website gives a video demonstration of how you do the test and likewise the pamphlet that comes with the test is well explained and makes it easy to do.

It must be said that the supportive pamphlet that comes with the test rather downplays the importance of positive reactions that only show what they call a mild reaction,

In our experience, even those milder levels of intolerance suggest that the reactive foods should be avoided until health has improved. The stronger levels of reaction are the foods that are likely to need to be avoided for much longer time frames as discussed below.

Can food intolerance be cured?

The answer to the question 'can food intolerances be cured?' is a definite maybe!

The gold standard for how long you have to completely avoid food intolerances is 3 months. Don't plan for a short-cut, this is the amount of time it takes for many of the white blood cells that are involved with intolerances to live through their life cycle. How you then go about seeing if you have cured the problem also needs great care. This process is called 'three strikes and you're in' and is described in the next section.

We hope that, and expect that, many children who have intolerances will be able to grow out of them if and when they take a break from what they are reacting to and get healthy.

However, the older or sicker someone is the less chance there is that this will happen without both a total avoidance of the food intolerances as well as taking measures to improve overall health. In particular it may be essential to nourish and support the immune system with herbs and other vital nutrients, more on this important subject here

Withania somnifera

Three strikes and you're in!

If you have accurately diagnosed a food intolerance then you must avoid that food completely for three months, not less!

Then, the first time you re-introduce the food, or one of the foods that you have been avoiding, eat only a tiny fraction of a portion. For example, a single bite of a piece of bread, or just a sip of milk, or just a half teaspoon of egg etc. Then wait for 48 hours and don't let yourself be tempted to eat any more of that food until that whole 2 days has passed.

Do not worry if you get some reactive symptoms such as a very mild stomach upset, or a slightly itchy skin, or a feeling of being a little edgy or out-of-sorts etc. This is normal, it can even to be expected and does not need to be over-analysed, but so long as those mild symptoms quickly pass within the 48 hours then your body has said 'ok, we know what that was but we aren't going to go to any serious lengths to react to it and try to stop it from coming in' In other words you are starting to develop some 'tolerance'.

If you feel a lot worse and it doesn't just pass away within the 2 days, then you need to accept that you are not ready to tolerate this food and you must go back to avoiding it again. It will no doubt be a disappointment but don't let it stop you trying again later, things change with time!

However, if you do soon feel better again then you should go to the second step. This is to eat a substantially larger portion of the same food but still not quite a full serve e.g. half a slice of bread, 50mls of milk, a quarter of an egg.

Again, wait for 2 whole days to allow your immune system to see that this substance does not pose any serious threat and again don't worry if you feel like you are reacting to it so long as it if fairly minor and, most importantly, it passes.

People are naturally anxious about this process but try not to over-think what is happening. So long as your immune system calms down your body will learn that this food is not a threat and can be safely consumed in larger quantities.

The third step, and again make sure this is after a full 48 hours, is to deliberately eat a full portion of the food and again this is where the two days wait to let everything settle is especially crucial. So long as you have carefully taken the first two steps without any real trouble the chance that this 3rd stage will go without a hitch is good because you have already been retraining your immune system.

After this process, you should carefully and systematically keep adding small amounts of the previously avoided food, reminding your immunity that this is a friend rather than a foe and establishing the food as 'safe'. Do not overeat it, or you may become intolerant again, but do not avoid it either. Hopefully there will be a happy middle ground, try to find it.

Calendula officinalis


Constitutional Health Note:

Finally, you might benefit from learning about your constitution to know what kind of foods, herbs, exercises etc. will work especially well for your health in general.

Constitutional health is an old and fascinating way of understanding our differences. There's a brief introduction here and a more detailed section on working out which constitution you are here

Please understand that I cannot personally advise you without seeing you in my clinic.
This living 'book' is my labour of love so, wherever you are, I wish you peace & good health!



© 2011 R.J.Whelan Ltd