Oh dear. A fellow blogger called Shinga has pointed me in the direction of two posts she has made about IGg food intolerance tests, and in particular about the rather inflated claims that some people have for these tests. And this is bad because I really do want to believe in the IGg test, mainly because all the other food intolerance tests I have ever come across are such bunkum, and surely we deserve one easy route to wellness?
But if the thing needs criticising then it needs criticising, and Shinga suggests a number of reasons why the IGg test might not be all that flash. She makes the following points, among others:
1) The one published, peer-reviewed study of IGg testing, which appeared in the journal called Gut, was criticised by a leading IBS expert called Dr Hunter because it produced pretty poor results compared to an old-fashioned elimination diet, where foods are cut out for a week or two at a time. Dr Hunter also said that the mere presence of high IGg levels may not correlate with a bad reaction to that food.
2) The authors of the Gut study responded to Dr Hunter by saying: “It is likely that only a subset of patients are likely to have an immuno-inflammatory basis to their condition and these might be the very individuals who respond to dietary exclusion based on IgG antibodies. This would fit with our results where only a proportion of patients responded despite all having antibodies. This, of course, limits the specificity and usefulness of the test unless such subgroups can be identified beforehand.”
So the study authors have agreed that their results were perhaps a little underwhelming. Shinga also quotes a number of health organisations who have made pretty clear statements that they don’t recommend the IGg testing (which are, as you would expect, in pretty direct contrast to some of the lovely alternative practitioners who like to support these kind of things 100% and not to really bother about boring stuff like evidence).
There’s still hope for the IGg test, and the Gut authors suggest that it might be useful in a subgroup of patients if nothing else. But I have to say that the more I read about it the more sceptical I get, and that’s not usually a good sign, because I tend to start off pretty damn sceptical anyway.
I do often wish that I could do a massive clinical trial which would be me versus the IGg – everyone in the IGg test group would take the York test and follow that diet and see how much better they got, and everyone in my group would give up gluten, dairy, alcohol, caffeine, spicy foods and artificial sweeteners, and we’d see who did the best…
Thanks for the shout-out, Sophie. I’ve done a number of posts on the topic of IgG testing lately. I have been really surprised at the dearth of published support for IgG testing in the diagnosis of food intolerance despite the frequently-repeated claims that they are “clinically validated” or have “sound science” behind them. There is no decent reason for the lack of a decent, randomised, placebo-controlled (active treatment diet of the sort that you describe) trial. There may not be much research money for this in the UK but the NCCAM spends around 100 million dollars a year on CAM research in the USA. It would not be that hard for YorkTest US to engage some relevant research centres and run an appropriate, multi-centre trial.
Hi Sophie,
I have to say the IgG test I had was completely inaccurate, though it give me food groups to think about avoiding.
I tend to agree with what Sharon says. The things that trigger my IBS (gluten, dairy and soya) would be only recent additions to our diet.
David
Hi Sharon – I don’t know a lot about the IGe test, but I do know that it’s about as mainstream as you can get in medicine, which generally means that there is a significant body of evidence and literature to prove that it works. Conventional docs tend to attack new ideas until they can really be proven. That just isn’t the case for IGg, there’s really only one proper published trial and that was equivocal.
Hi Sophie – I went digging in the archives to provide accurate info regarding the “allergy” tests I’ve undergone. First were the scratch tests/injections which I always thought were IGE mediated. The tests I had done were rated on a scale of 0 to 10 with plus’. Then there was the IGG rast test which is a blood test and analyzes dozens of foods with a scale of 0 to 2300 and beyond. My reaction to eggs was 3800. Lastly there was a “food intoleranc test” that I believe used to be called cytotoxic. The cytotoxic test is described as follows: In vitro testing where food extracts are mixed individually with patient plasma containing white blood cells, platelets and red blood cells. The mixure is then observed under a microscope for toxic reactions. Damage or death of blood cells indicates a positive reaction to a specific food. Like I indicated in my previous post, there were numerous overlaps for me.
I believe that a test similar to the cytotoxic test is what is utilized by the Eat Right for Your Blood Type author. According to him, people of the same blood type have similar if not identical results on the test. I also took a “total IGE” blood test. Normal is 0 to 12. I was a 49. I have a friend who’s in the thousands. His intestines are great but he has nonstop eczema/itching. He’s up most nights scratching. Very debilitating for him. He says he pounds the walls at night sometimes. The day is done. Sweet dreams all. Sharon
has anyone ever tried ZEFARIL Body Detox Cleanse System Combo: Zefaril Colon Cleansing & Zefaril Fiber? if so what is your take on it the product?
Deshield – I had a quick look at the Zefaril website, and their colon cleanse product is basically just the same as most other products of the same type. Among other things it contains the strong stimulant laxatives senna and cascara sagrada, so it will certainly give you diarrhea, but it probably won’t do much more than that.
my son has a level ige of 600.dr. says dust. he is to be put on the xolair soon.will the colon cleanse help him
Hi , just wondering whether to try the York test.
Anybody out there had it,was it any help ?