There are not “links” between allergies and autism. The problem with so much of what happens is that people confuse correlation and causation. They are not the same. I have friends who have children who are autistic. These children are wonderful people (I have volunteered my time at a local school that has many in attendance). I understand a parent’s desire to “make their child whole” but MOST ( not all) are not competent or capable in the research fields. The latest fad diet, the latest round of “what works” has them running in circles. It gives false hope and false direction. Many of these parents becaome “crusaders” and we as a society are the worse for it ( eg shots cuase autism).
Somebody has to crusade. And parents seem to do it better than the DYFS types and other government agencies, who just say 'trust me' and go on to other priorities.
If you want this to be a priority, you have to be out there competing with the crusaders for HIV cures, breast cancer cures, etc.
You are introducing a strawman argument here about correllation==causation. I did not say that. 'Link' is defined as correlation, not causation. The link is that both are in a boom time, raising the possibility that they share a cause, not that one causes the other.
Sometimes, the 'latest fad' pans out. Note the many recent articles on how a low-carb (e.g. Atkins) diet beats out low-calorie or low-fat diets. A lot of M.D. and Ph.D. folks came down hard on the Atkins diet when it first came out. Maybe it wasn't the last word in low-carb science, but it really upset the applecart of the carbs-are-great crowd.