"Pros and Cons of Gluten-Free, Casein-Free Diets for Autism"
When you read in alternative medicine journals
that there’s “a great deal of evidence
that foods containing casein or gluten
contribute significantly to [autism] and should be eliminated from the diet”,
almost always leading to symptomatic improvement,
they’re presumably talking about the published anecdotes
and case series that claim wild success, but had no control group,
though there were two year-long controlled trials
that also showed remarkable benefits, but couldn’t discount placebo effects.
The double-blind studies that did control for placebo effects
failed to find benefits, but they only lasted a few weeks.
This was to be the study to break the logjam,
a months-long, double-blind controlled study.
They put 14 kids with autism
on a gluten-free, casein-free diet for 4 to 6 weeks and then,
for the next three months, challenged them every week
with double-blind, placebo controlled food tests,
secretly giving them gluten, just gluten,
or just casein—or both, or neither,
every week, month after month.
Here’s what happened to each of the 14 kids
in terms of their social relationships and their language skills
throughout each of the challenges.
And, bottom-line?
Nothing.
No apparent impact on behavioral disturbances
or autism-related behaviors.
So, does that mean case closed?
Well, proponents of autism diets
“might regard the 4–6 week implementation phase
prior to the challenges as too short
for the gluten-free, casein-free diet to take full effect.”
In other words, one could argue this is yet
another double-blind study that didn’t give
the diet long enough time to work.
And so, maybe the kids were still feeling the effects
of gluten and casein they consumed more than a month previously.
And so, no wonder extra gluten or casein didn’t make them even worse?
It’s possible, I guess, which is why you'll see
systematic reviews of the sum total of evidence,
like this one published 2017 in the
journal of the American Academy of Pediatrics,
concluding that although some studies showed benefits,
the data are inadequate to make conclusions either way,
in other words, the “SOE”— the strength of evidence --
is considered insufficient to endorse such diets.
What’s the harm in giving it a try, though?
Well, given the effort, time, and money
that a gluten-free, casein-free diet requires,
knowing whether it actually works, would kinda be a good thing to know.
I mean, there are downsides.
“Being on a special diet can have unintended
negative social consequences,
when children are not able to participate conventionally
in birthday celebrations and class treats
or eat in restaurants or other people’s homes.”
Autism can be isolating enough as it is.
The overall evidence for the effectiveness of these diets is weak.
And thus, these diets cannot be generally recommended as a treatment.
Yet, parents continue to give it a try
figuring, “Look, the drugs don’t work,
in terms of helping the core symptoms.
So, why not just give it a try and leave no stone unturned.”
I can understand that;
however, there are the potential downsides,
like further stigmatization,
diversion of resources away from other treatments,
and, they suggest, a concern about nutritional deficiency.
What they’re worried about is bone health.
Those with autism are at elevated risk for bone fractures.
Now, lower bone mineral density in individuals with autism
may be due to a variety of factors:
lack of vitamin D,
chronic use of medications that can weaken bones,
lack of weight-bearing exercise—
but, maybe dietary restrictions play a role.
Do children with autism on gluten-free, casein-free diets
have lower calcium intake?
Yes, in fact, 9 times the odds of failing
to meet recommended calcium intakes.
Does this translate out to reduced bone mass?
Maybe so, as those on casein-free diets
appeared to have less bone development.
Now, there’s controversy over whether dairy products
are the best source of calcium,
but that is where most kids are getting their calcium.
And so, if you remove dairy,
you have to replace it with other calcium-rich foods.
As the study they cited points out,
there’s lots of nondairy sources of calcium—
but, they only provide calcium if you actually eat them.