I really do think the BBC Food Programme is about the best of the food podcasts. I particularly enjoyed a recent episode on "free from" foods http://www.bbc.co.uk/programmes/b01dhcg2 which presented what I found to be a balanced approach to food allergies and intolerances and the food industry's response.
Some of the things I noted:
There is a difference between allergy and intolerance. I recall trying to explain to someone years back the difference between a dairy allergy and lactose intolerance, but the distinction applies to many more foods - not just milk and wheat.
There's a lot of self-diagnosis, often because GPs are ignorant of dietary issues - but that doesn't mean that self-diagnosis is always correct or helpful.
There are many reasons for increases in food allergies and intolerances. With globalization of the food supply and the migration and mobility of people, most of us eat a much greater variety of foods that our parents and grandparents did, and source our diets from greater distances. Our environments are too clean, and at the same time filled with 10s of thousands of human made chemicals. Some food additives have introduced populations to ingredients from foods with high incidences of sensitivity - like protein from lupines.
And what about the anti-gluten mania? The percentage of folks with celiac disease remains constant, but gluten intolerance or sensitivity may be increasing simply because there is more of it our diets. When I was a child, for example, spaghetti or macaroni and cheese was an occasional food. Now many people eat pasta several times a week or more. The wheats used to make industrial bread are higher in gluten. And wheat is just more common in our diets. We know that with global urbanization portable foods where bread is central - the sandwich and its variants - are ubiquitous.
The "free from" foods in our markets are, for the most part, highly processed foods. I'm not talking about the silliness of labeling foods like olive oil "gluten free". I'm talking about the gluten free cookies, "breaded" frozen foods, alternative milks with a long string of ingredients, etc. So a question that remains is are we substituting one highly processed food for another, rather than getting back to simpler, whole foods, or home prepared alternatives?