Wow. I just wanted to write a blog entry. And now there are five. The topic of “testing for food intolerance” is incredibly diverse. I have only scratched the surface with my research and have come across some fascinating findings. The reactions to this blog were also overwhelming. Never before have we had so many readers within 24 hours and the spread on social media was enormous.
I personally learned a lot. For example, a visit to the doctor is almost always cheaper and certainly always better than a self-test. I learned that I should go to the doctor despite the home test, because someone has to explain the findings to me. And a Facebook group is definitely the wrong place for this. I’ve also learned that by writing such an open and honest blog, you offend a lot of people who swear by such tests and receive a lot of hate, nasty emails and negative Facebook posts as a result. But the positive reactions far outweighed the negative ones. Never before have I received so many nice and positive emails in response to a blog post. Thanks for that!
Main problem: lack of conversation
The biggest problem with all the tests was the lack of anamnesis, i.e. the lack of a doctor-patient consultation and – also caused by this – the dietary recommendations, which were completely wrong for me. Without any patient consultation, the provider of such self-tests naturally knows nothing about my other illnesses. Self-tests, even if they provide valid results, are only ever one part of a diagnostic puzzle that can only be put together by someone who knows their way around. And just because a test provides valid results does not mean that the result is clinically relevant. Put simply, the IgE test works, and the IgG and Flora status also provide “scientific” results. The interpretation of clinical relevance alone and, above all, the establishment of a link between result and “disease” is not serious.
Stool tests
The stool test for gluten gave me the right results, but that was due to the probability. These tests result in approximately 10% positive diagnoses in both healthy and diseased people, so there is a 90% probability that a celiac disease patient will receive the wrong “diagnosis” and a healthy person will receive the correct one. These tests are therefore clearly not recommended.
The intestinal flora status gave me little insight, but it works. The interpretation is difficult, even I as a nutritional biologist did not know what to do with the findings. You can only make really meaningful statements about your own current microbiome if you carry out several endoscopic tests with precise species analysis. This is expensive and only makes sense for special indications. Taking any probiotics due to the flora status will probably do as little harm as it will help. But these stool analyses give you the feeling that you are doing something good for yourself – scientifically supported. You will find many people who will swear that they have found an improvement in their symptoms because of these tests. Regardless of whether it would have worked without it. Well. Let us rejoice with them that they are doing better.
Blood tests
The IgE home test provided correct results and the doctors interviewed did not criticize this test as such. Only the medical significance of the test is not given without additional information, the possibility of false or clinically irrelevant results is very high. It also costs a lot and would have been free at the doctor’s.
The IgG4 test showed relatively accurately what I eat. Nothing more. It cannot provide any information about food intolerances or allergies. Nor can it make a valid statement about intestinal permeability (“leaky gut syndrome”). The diet tips I received from the provider were fundamentally wrong in my case and, if I had followed them, would have caused severe digestive problems, pain and long-term depression.
IgG4 test with fatal dietary recommendations
I can and should eat apple, cherry, orange and grapes according to the dietary recommendation of the IgG self-test – mind you, as a fructose-intolerant person. I’ll spare myself this self-experiment because I don’t feel like going to the toilet for three days.
In addition to the intolerances, the IgG test provider also diagnosed me with“leaky gut syndrome“. I should therefore take probiotics. I was advised to eat sauerkraut because it is a natural prebiotic. I should therefore also eat beet. Both would cause me – as I said, I have fructose intolerance – bad diarrhea and stomach cramps.
I find the story with the probiotic interesting. Since I had been taking exactly the recommended bacteria for two months before my gut flora check – I wanted to see if this could be detected in the flora status (it can’t…), the whole thing makes little sense, or rather it shows that the recommendation is not correct. If it were correct, my permeability would be better. I predict that the manufacturer in question will also launch probiotics on the market in the next few months, which will then be recommended as part of the diagnosis.
My conclusion
Self-diagnosis by means of such tests can lead to the doctor’s diagnosis being incorrect because I have taken certain precautions. Self-diagnosis can lead to major health problems. Home tests without competent medical advice can promote eating disorders or serve as a social legitimization for them; they cannot provide meaningful nutritional recommendations because there is no personal discussion or medical history.
Smokers also live to be 100
Yes, you can always find someone for whom the tests have worked. You can always find someone who lived to be 100 despite smoking 40 cigarettes a day. You can also find athletic vegans who have a heart attack at the age of 30. This is usually because it was a coincidence. My IgG test would also have brought slight improvement if I hadn’t known about my lactose and fructose intolerance. I would have cut out all cereals, all dairy products and dozens of other foods, i.e. lactose-free and also lived a very restricted life in other respects, and would certainly have felt better on some days than before. Namely, if I hadn’t eaten fructose by chance. But that would have been rare, as I ate a lot of fructose and sorbitol according to the dietary recommendation and would have had quite a few problems as a result. But maybe after a few months my second test would have jumped on it and at some point I would have only eaten rice and potatoes. Symptom-free. Until I would have developed deficiency symptoms or even an eating disorder and without ever knowing what my real problem was…
All in all, we must advise against such self-diagnoses and home tests. I know people like to berate doctors these days and yes, there are certainly doctors who are not good at their job – I know a few too. But there are also car mechanics who are bad at their job, so not all mechanics are bad. You just look for a new one that you are happy with and can work with. You still take your car to the garage and – yes, every comparison is flawed – you don’t tinker with it yourself. At least not me. And that’s how you should treat your body. In collaboration with a doctor and, in the case of a correctly diagnosed allergy or intolerance, with dietary support from a nutritionist.
It would be really great if such tests could deliver useful results. I would be the first to be as happy as a child. But they don’t. Such tests are simply not useful. Sorry.
