Allergy & Intolerance Tests

Unsure if you need an Allergy or Intolerance Test?

In my clinical – and, sadly, personal – experience, food sensitivity is an issue in most cases I come across. The vast majority of people benefit from removing the key allergens; it sort of gives the body a chance to heal without them putting extra pressure on the body, I think. That’s why my first approach with anything is usually the Gut Plan. That helps you remove the key allergens and do some gut and liver MOT work.

It used to be that removing wheat and dairy and doing the Gut Plan was enough. Nowadays, though – and I’m not totally sure why – it seems most people need to remove gluten – and sometimes all grains – and dairy to get well. This tells me that a) these foods have been changed in some way – more gluten, more hard to digest somehow, use of agrochemicals our bodies react to or can’t assimilate in some way etc and b) that our guts and livers are not working as optimally. The two are more than likely connected!

Anyway, if you are suffering from any kind of chronic issue that isn’t going away, check for a food sensitivity problem. You can just choose to remove the foods, but bear in mind that you have to be eating the foods to test most allergy/intolerances and, more often than not, if you try to put the foods back in to test, you’ll feel crap! Of course, that tells you there is a problem in itself. But, if you are going to want to see which foods might be the problem, see something on paper for schools, doctors, relatives, yourself, test first. This is especially important for gluten related illness including coeliac disease.

So, my advice is to test first and then do the Gut Plan, removing any foods that crop up as severe issues on your results.

The Allergy 101 Factsheet and the whole Allergy/Intolerance section here will help give you much more information. This is a minefield, trust me!

OK, you’ve decided you need to do some testing, so let’s see the best way to do that. Strap yourself in; this is complicated, but I’ll try to simplify it down for you, I promise.

Please bear in mind that we don’t yet know all the likely mechanisms involved in sensitivity, so we can only test for the ones we do – and I try to keep up with the latest advances to help you get answers that are as accurate as possible, but 100% accuracy simply doesn’t exist yet.

Testing Summary

If in doubt on what food intolerance test to do and you are still eating the suspect foods, choose the FIT Test 132 (RG). Don’t forget to do a GAM Test (PHC) to check your levels of total antibodies first if poss – see why this matters below. If you are no longer eating the foods, choose an ALCAT (RG). If you are autoimmune or at risk of it, or suspect a gluten related disorder, look at doing some Cyrex testing. For specific issues like Histamine, DAO, Oxalates, Tryptase, Fructose and Lactose, see the recommendations below.

Allergy Testing (IgE)

The medical definition of food allergy is an immediate immune system reaction sparked by the binding of an IgE antibody to a mast cell thereby causing a release of histamine. It is this type that confers a risk of anaphylaxis. Here, you can look at foods or inhalants eg. for hayfever, rhinitis, asthma sufferers etc.

If you’re not sure if IgE allergy is involved, start with a Total IgE Immunoglobulin E Test (MC). If this is high, then allergy is involved somewhere and you would then start to test for allergens. If not, then start looking for intolerances instead.

You can choose one of several IgE Allergy tests from MC. Allergy Screen UK Blood (MC) tests for several common foods and inhalants. The Allergy Screen Inhalants and Foods (MC) checks for a whole load more, or you can do a grains-only check with Allergy Screen Cereals (MC). You can also do an Allergy Screen Antibiotics test (MC). It is useful to look for both inhalants and food in my clinical experience. Go to Medichecks here.

Food Intolerance/Sensitivity Testing (IgA, IgG, IgG4, Complement etc)

Even though IgE classical allergy is the one most accepted in mainstream medicine, food intolerance is much more prevalent, certainly in my experience! The overall definition of food intolerance is a delayed reaction to a food which does not involve IgE, the symptoms of which are extremely varied and can be behavioural, emotional or cognitive as well as physical.

It is worth noting that a reaction may only be ‘delayed’ by a matter of minutes, but is usually from 2-4 hours later and can last several days (3 mostly, but more mildly up to 10 is very common). There is a sense that allergy is worse to have than food intolerance and that is understandable because of the risk of anaphylaxis. However, food intolerance sufferers are often sensitive to more foods and have more frequent reactions affecting more body systems so it can be awful to live with in a different way.

Some types of reaction, but not all, involve antibodies such as IgG, IgA and IgM. IgA signifies a developing problem, IgM suggests an early reactivity and IgG, the most common one tested for, usually denotes a chronic problem with a food. There are four sub-classes of IgG: 1-4.

Measuring total immunoglobulins first….

Be aware that some people can have low levels of these antibodies if the immune system is not brilliant. If doing an important – and often expensive – food intolerance/sensitivity test, it is wise to do a quick check on your totals. You would use a GAM Test (PHC) which will show you if any of your IgG, IgA or IgM antibody levels are low. If, say, your IgG was low in total ie. you’re not producing much, then any further testing that measures IgG might show allergen reactions are lower than they really are. It’s not that you can’t have those tests done; more that you have to factor that in when looking at your results. In that scenario, you’d think: ‘Aha, this IgG test result for beef is borderline, but I know my IgG is low so it is probably more likely higher than that and positive.’ Do you see?

The importance of complement…

Research suggests that most of us can develop IgA and IgG antibodies to foods and that whether we will react to them or not depends on if those antibodies have activated complement, a part of the immune system known to trigger an inflammatory cascade in the body. Newer tests have been developed that now allow us to measure the antibodies and see if they are bound to complement. This usually results in far fewer positive foods and helps us target the key problem foods rather than getting a whole list of possibles. This is good news!

The Food Inflammation Test (FIT) (RG) is, happily, a dried blood spot test so no need for veinous blood samples or centrifuging, though note that you need to provide several blood spot samples, not just one. It measures all four IgG sub-classes and complement (C3d). 132 foods, additives etc, including all of the gluten cross-reactive foods in Cyrex 4 as well as candida and zonulin to check for leaky gut.

We all have some candida in the system. If you find it bound to complement, it has gone through the gut barrier. They do a meal plan with one of their tests (the FIT Plus, RG) but it is quite US-heavy and I didn’t rate it that much so I’d choose the cheaper one without the meal plan. They also do a smaller FIT Test 22 foods test (RG) with most of the key problem foods included if you want to test fewer foods.

Do bear in mind that you have to be eating a food regularly for an antibody to show up on testing. After a couple of weeks, the antibody levels start to drop so you won’t find them!

Generally, you do the FIT test, knock out the highest offending foods for minimum 8 weeks (preferably 12), re-test to see if the immune complexes have come down sufficiently and, when they have, you reintroduce one at a time, noting symptoms. You then retest if you wish again (or just enjoy your new-found energy and health!) and make sure that the immune complexes are not rising again.

If you still react to something, you need at least a year off it, by which time the inflammation complexes should have reduced sufficiently (the average seems to be 10.5 months according to the lab), then start the reintro and retest process again.

In general, anti-inflammatory treatment should be done alongside the removal of the foods to help lower the systemic inflammation in the body.

orange cat sleeping on white bed
Here’s a very chilled-out kitten to give you some light relief…..I know this is tough going!

Better? OK, on we go…

Other Food Intolerance Tests

I rate the FIT test for lots of reasons, but there are alternatives. With all of these tests, check what foods are included to make sure it suits what you need and your kind of diet.

Cyrex testing (via me) is the other biggie in this category. They are unique in the allergy testing field in that they measure cooked foods and foods as we eat them, so the allergy substances used by the labs are a bit more ‘normal,’ if you like. They also look for hidden parts of foods like gums etc. They combine IgA and IgG so you will find early, developing issues as well as chronic ones you’ve had for a while.

Here, you would do a mixture of Cyrex 2 (leaky gut), 3 (gluten illness), 4 (cross reactive foods, also covered in the FIT above), 10 (the biggie and best once you’ve done 3 and 4), 11 (chemicals) and 12 (pathogens). You can still get all the Cyrex testing through me here.

What if you’re not eating the foods anymore…?

If you are not eating the foods anymore, you can’t do the above antibody type tests. But you can do an ALCAT test – yay! This is a kind of cellular response test. Essentially, the lab looks to see if your white blood cells change size when provoked with an allergen, suggesting they have released allergy mediators like histamine, leukotrienes etc which are what cause symptoms. So, there is no need for you to have eaten the food as they are not looking for an antibody.

You can do ALCAT 150, 200 or 300 all the number of things tested) and ALCAT Chem – for chemicals (all RG).

Other Sensitivities: Lactose, Fructose, Histamine, Sulphites, Oxalates, Nightshades

This is where things get even muddier, sorry! These are usually not the same type of delayed sensitivity reaction at all. The situation differs for each type of sensitivity, or malabsorptions as I think of them. Have a read of this page on the site here.

Lactose intolerance is not, strictly speaking, an intolerance at all but a deficiency of the enzyme lactase which digests the lactose sugar in milk. In lactose intolerance the undigested lactose sugar ferments in the gut giving the typical digestive symptoms of lactose intolerance. Lactose intolerance has nothing to do with cow’s milk allergy or delayed food intolerance, and although it is possible to suffer from both, they are totally separate conditions. Very few outside the medical profession understand the differences so the three terms are used indiscriminately.

Lactose can be tested with a genetic swab or a Lactose Intolerance Breath Test (RG). The jury is still out on which is best so do both if you need to. Just be careful because giving a lactose-sensitive lactulose to do the test with can unnecessarily making them poorly!

Fructose can be done simply using a breath test; there isn’t a gene test yet.

Histamine is another type of test entirely as rather than a sensitivity to it, or a malabsorption issue, this is an issue of not breaking it down enough. A case of histamine excess, if you like. You can read my Histamine Factsheet for much more about testing and treatment, but essentially the main approach is to try and find if you have an excess of histamine in your system and if you have enough of the key DAO enzyme needed to break it down.

You can use the Biolab Histamine and DAO tests (PHC) for those.

Note that histamine will rise after a meal as it is needed to release gastric acid into the stomach so best to take your sample in between meals.

You can also check your genes (as discussed in the Histamine Factsheet above). Use the Lifecode Gx tests (PHC).

You can also check for Tryptase issues. Tryptase is also released, like histamine, in certain kinds of reactions. It’s often looked for to help confirm MCAS/MCAD or mastocytosis. Use the Tryptase Test (PHC). The three key MCAS tests include Tryptase, Methyl Histamine and Prostaglandins D2, F2 Alpha and DM. You can get all of those through me here.

Oxalates – some people have high levels of oxalates in the body which can be linked to kidney stones, pain disorders like vulvodynia, interstitial cystitis and to behavioural conditions in children, to name a few. You get oxalates from food, yeast and you make some inside the body. The issue comes when you are getting too much in total, which you can measure using the Oxalate Urine Test (MC). You can read more about oxalate testing here and GPL has a good blog post on it here.

I am not currently aware of effective ways of testing sulphites, salicylates, nightshades etc except for food challenge.

Phew: a minefield, huh? Are you still with me? Remember to download the free Allergy 101 factsheet for much more on all this.

Testing Summary

If in doubt on what food intolerance test to do and you are still eating the suspect foods, choose the FIT Test 132 (RG). Don’t forget to do a GAM Test (PHC) to check your levels of total antibodies first if poss – see why this matters above. If you are no longer eating the foods, choose an ALCAT (RG). If you are autoimmune or at risk of it, or suspect a gluten related disorder, look at doing some Cyrex testing (me). For specific issues like Histamine, DAO, Oxalates, MCAS, Fructose and Lactose, see the recommendations above.

Testing Tips…

Q: What else could cause a high IgE other than allergy?

A: A high IgE result can signify a parasitic infection too, check the gut tests for help if you suspect that.

Q: Can I do the Cyrex Tests if I am off the foods?

Generally, you need to be eating the food regularly to get a positive antibody test, although Cyrex do advise a way forward if you wish to re-introduce foods for testing (not that I necessarily agree with that but it’s an option..). There is a whole load of testing hints and tips for the Cyrex tests in the Gluten Tests Overview, so do read those fully and it should answer your questions – towards the bottom of that section.

Q: Can I do allergy or intolerance testing for my child?

A: It depends on their age really and the type of testing you are planning.

IgE classical allergy testing can be done reliably from about 9 months onward. This is because babies do not have a fully developed IgE response until about 6-12 months. The same therefore goes for reliable skin prick testing in my view as that is looking for IgE responses too.

The usual issue with blood tests for little ones is getting the blood. For these tests to be processed the lab needs 1 full serum tube (8-10ml) of blood which can be challenging to draw from children as young as 2 or 3 years old. Some phlebotomy clinics are reluctant to take blood draws from children at such a young age.

Cyrex testing is suitable as long as they are eating gluten or the allergens being tested, but the issue is with getting enough blood as per.

Q: Will steroids affect my results?

They could do, yes. If you have been on a short course of steroids (inhalers or tabs), then the labs usually say test after a few days off them: at least five. If you are on long-term steroids, your results could be affected. It doesn’t necessarily mean you can’t have tests done but you would have to bear in mind your immune system is likely to be suppressed and therefore any results might show lower than they really are. Read the various test information pages for any specific instructions and do talk to your health professional for advice.

Q: Why is the histamine done in plasma and not whole blood?

A: I am aware that eg. Walsh protocol advises whole blood histamine and Biolab used to do it in whole blood but have now swapped to plasma or urine. I asked them why..

“We used to measure whole blood histamine levels but discontinued it in favour of plasma or urine histamine both of which we believe are more sensitive tests for histamine levels (plasma and urine are equally reliable). I know that the Walsh protocol is quite strict on the sample requirements, but in practice we don’t have any problems finding either high or low levels of histamine using the plasma and urine tests.”

black and white maltese puppy
If you’ve read this far and got to the end, you more than deserve a cute puppy pic! Enjoy – and go and rest..