Dr. Elder: I have been in the autism field since the early ‘80s, and I learned a long time ago to listen to parents. I kept noticing that it was becoming more and more common that parents either had their children with autism on a trial of a gluten-free, casein-free diet, or they were seriously considering doing so. This type of diet was not well-studied in any formal, randomized, clinical trials and there was no empirical evidence of its effectiveness. I have noticed over the years, because we don’t have a cure for autism, people are desperate to try to find something that works. And sometimes they report that they see effects when they really aren’t that noticeable to others who can be more objective.
CCPR: Why do you think that is?
Dr. Elder: Some people have called this the “parent placebo effect.” I don’t have a child with autism, and I can only imagine that if I did I would be trying everything possible, and I would really want to see positive effects, and any small positive effect would be huge to me. I think in some cases, not all, some objectivity may be limited.
CCPR: In one of your papers you referred to a study where parents were unaware if their children were or were not being given sugar. Those who thought their child was having sugar answered differently from those who thought their child was having sugar substitute (Feingold BF. Why your child is hyperactive. New York: Random House;1975).
Dr. Elder: Right. I mentioned that as an example of the fact that we have to be concerned that there is a possible placebo effect. In that study parents were told one time that the child was getting a drink that did not contain sugar, and they were told another time that they were getting a drink that did contain sugar. When they thought the child was drinking the drink with sugar, they saw more hyperactivity, but actually it was just the opposite according to clinical measurement. It was all about the power of suggestion.
CCPR: And you tried to design a study that would take this into consideration.
Dr. Elder: My research team and I set up a 12-week double blind, randomized, placebo-controlled trial of a gluten-free, casein-free diet for children with autism. For half of the 12 weeks (6 weeks) they got the gluten-free casein-free diet, and for the other half they got a diet that contained gluten and casein. It was a small trial. It was very difficult to get the children to comply with the diet. We provided all their foods and they were instructed not to have anything else unless it was approved ahead of time by the dietitian. Parents were great but they admitted that sticking to the restricted diet over time was very hard (Elder JH et al, J Autism Rel Disord 2006;36(3):4l3-420).
CCPR: And what did you learn?
Dr. Elder: Our findings from comparing the two groups were not significant when we analyzed them, but we had some families who said they saw effects that we didn’t measure with the instruments we used. They saw enough effects, in fact, that some decided to keep the children on the diet. So we thought that was interesting. Since that time, at least one other randomized clinical trial had almost the exact same results that we did. So the take away messages were, first, we need to have more rigorous trials with larger samples. And, I am beginning to think more and more that there also may be a subset of children who are responders that we have yet to conclusively identify.