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How accurate are clinical blood tests and breath tests?

Doctors know clinical testing for food sensitivity is unreliable and delivers ambiguous results, but many patients still insist on going ahead.

And here at foodintol we are constantly receiving letters from people who have had the tests, but are bitterly disappointed.
Here is one:

"I'm rather annoyed. Recently I sent for a laboratory blood testing kit and when the results letter finally arrived I was instructed to leave out wheat (no mention of gluten or yeast), some milk products, certain fruits and vegetables and soy. I've been doing that for 4 months now.
But even though some things are better, some symptoms never went away and that's really annoying. What now?

I paid over £250 British pounds (at today's rates that's $370 American dollars!) to get the kit and have the tests done, and there has been no follow-up. But I'm following the instructions - so why am I still unwell?" David T., (UK)

Can you trust blood test results?
Hi David - No follow-up, persisting symptoms? And that's quite a lot of money, isn't it – on current rates around $550 Australian dollars.

Okay, we all want a quick fix. And lots of online laboratory testing packages promise just that.

But the truth is - no single blood test will conclusively prove multiple food intolerances. In fact even a negative result for Celiac does not rule out Gluten intolerance.

You actually need many blood tests done in conjunction with other investigations like scans and biopsies to get a positive result. And that can take weeks and be expensive.

That's why a doctor should only regard a single blood test result as a guide only. Most often, to confirm or clarify test results a good doctor will ask you to do an elimination diet.

(FYI The Tuesday Club uses Elimination diet methodology, it's guaranteed to be accurate and is only $1 a day.)

Doctors trust Elimination Diets
Doctors know elimination diets work. Blood tests can be painful and a hassle. Even today the testing laboratories struggle to get reproducible results. That means when the blood sample is split into two and the same test done on them in the same laboratory the results can vary widely.

And any scientist will tell you if a test is not reproducible then it is considered worthless. The tests can also be expensive and time-consuming . . . especially when they bring 'inconclusive' answers.

But the most damage happens when the tests miss food intolerances. The classic one is for Celiac Disease. If a person gets a negative ressult for Celiac Disease they think they can go on eating Gluten without harm to their body.

However they could still have Non-Celiac Gluten Sensitivity (NCGS) which is not picked up by this test AND – is much more common! Up to 1 in 7 people is affected by NCGS.

This is a travesty – but happens all the time. The person's symptoms persist and get worse with age as they keep eating the wrong foods, and their risk of serious disease increases every year: diabetes, arthritis and depression among others. We take our information from respected Medical Journals, References

There is nothing as accurate and reliable as a purpose-designed journal and some comprehensive food substitution guides.

But the doctor simply doesn't have the time to take you through all that. That's why we created The Tuesday Club.

The Tuesday Club's Detection Diet is guaranteed to find your food intolerance and it costs around USD$2 a week to be a member!

Blood tests frequently inaccurate or inconclusive
Have you had a blood test for Celiac Disease that came out negative or inconclusive? Did you know you could still be Gluten intolerant? You might have Non-Celiac Gluten Sensitivity (NCGS) which is actually much more common.

The danger is – if you got a negative result you'll think you can keep eating Gluten without damage to your body. Wrong! It actually puts you at much greater risk of serious disease later in life.

Unfortunately your doctor might not be up to date with the latest in testing. The fact is, most blood tests for food intolerance are inconclusive and/or inaccurate and even worse, put many of us on the wrong track.

Clinical tests for food intolerance
There are lots of clinical tests that give an indication that there might be a food intolerance. For example, there are blood tests like IgA and IgG for Gluten.

But neither of these alone will give conclusive proof of Gluten intolerance. (Also, even if this test is negative - NCGS should not be ruled out.)

The story is the same when for blood tests for Dairy intolerance. And for Yeast sensitivity and Fructose malabsorption there are NO effective blood tests. Instead other things like hydrogen breath testing are used and/or the patient history and lifestyle are noted and analysed. However these are not fully reliable.

So why use these tests?
Essentially these types of test are like pieces of a jigsaw puzzle. They give your doctor some indication of some parts of the problem, but not the whole picture.

Because food intolerance presents itself in such a wide spectrum of symptoms, the doctor must run lots of tests and scans and biopsies and gradually build up a picture of each patient's problem.

So paying lots of money for a mail order blood test kit seems rather poor value, doesn't it?

If you have symptoms they are not only distressing, they will become worse with age. So how can you find out for sure which is your Problem Food?

But only the Elimination Diet gives proof
Even if your doctor orders these tests and procedures, he/she will likely ask you to do an Elimination Diet to make the picture clearer, and to confirm test results. As we said above, doctors know Elimination Diets work.

(The silly thing is - you could do an elimination diet first and have a positive result much sooner, couldn't you?)

That's where The Tuesday Club's Detection Diet is brilliant. It's an easy version of the elimination diet and it will pinpoint your Problem foods quickly and easily . . . guaranteed or your money will be refunded.

Read Helen's story about all the tests she had.