'I forget the exact figures but something like one in one hundred people are actually intolerent but one in ten say they are.' Made up, surely!!!
There is so much unknown about the immune system and new factors being identified all the time that may impact it. And the answers to many health questions seem to be so complex and individual there is very little reliable, truly unbiased, long term research which takes account of all the necessary factors, this is complicated! While some experts have some of the answers no one has them all.
I eat a gluten, dairy and low sugar diet, as do my three children. I wish I didn't but with these restrictions, one son no longer has ear infections every three weeks and constant loose bowels, the other doesn't react to everything he comes across, nuts, seeds, red meat, red fruit, citrus fruit, deadly nightshade vegetables, anything containing petroleum, plastic, rubber, feathers, animals, straw, reactions ranging from exhaustion, constant runny nose, coughing, wheezing, vomiting, severe eczema, hives, itching, to anaphylaxis. And I used to get frequent ear infections, mild eczema, frequent bouts of thrush and mouth ulcers. Now, if I eat gluten, dairy or sugar I get mouth ulcers but not the other reactions I used to get when I ate gluten or dairy. I gave up looking for a test on the NHS that could rule in or out the things my family react to and are better without as reintroductions did such a huge amount of damage.
Thankfully we do now have an immunologist who monitors our nutrition and absorption levels and believes that there are many people for whom dairy and gluten are not good things to eat both for their immediate and long term health.
I wish we were not in this situation but having read widely on the subject over the years, the freaks (followers of GAPS diet, WAPF, Healting tooth decay naturally, Paloe diet,) do seem to be the ones who have immune issues and benefit when conventional medicine does not make them better.