Food Causes ADHD? Can Diet Cure It?

Here’s one worth watching. A recent article from the Netherlands, published in the February, 2011 issue of the Lancet has suggested changing the diet of some children may cure their attention deficit/hyperactivity disorder (aka ADHD). The lead researcher, Lidy Pelsser in a recent NPR interview stated what might be considered a radical concept, that “food is the main cause of ADHD. ”

Seriously? Maybe so. (Insert gasps from parents, skyward eyebrows from docs, and a sharp intake of breath from Pharma companies, here).

Here’s what we know. ADHD affects about 10% of North American children (or, about 5% of children when measured globally). Research from the last three decades has characterized ADHD as a phenomenon often caused by a variety of factors, including genetics, prematurity, and/or a child’s environment. Children identified with ADHD may be parts distractible, inattentive, impulsive and classically, tending to bounce off the walls. And, in a significant number of cases, children with ADHD have a co-travelling learning disability or behavior problem.

Given that the current treatments for ADHD are a mixture of behavior modification strategies, counselling (when available), and stimulant or psychotropic medications about which many parents have deep suspicions…Well, given that, being able to address this tangly condition with changes in diet has obvious appeal.

That food intolerance or hypersensitivity can have an impact on a variety of organ systems is also well known to most folks. Children and adults report a range of symptoms, such as eczema, wheezing, or GI upset when they ingest certain offending foods. Historically,the studies drawing a line between diet and hyperactivity or inattention have been small, and not that compelling. Some data have suggested food colorings and preservatives may increase hyperactivity in susceptible children, but do not themselves cause ADHD. Here’s another chestnut: it is regarded as a medical myth that sugar causes children to become hyperactive. (We’ve all met ricocheting kids at birthday parties who might dispel that notion after the cake is served, but I digress….)

In the case of these Dutch researchers, a study was designed to investigate the controversial belief linking certain types of foods or food additives to ADHD-type behaviors to a sample of children. Here’s the crux of their question: were the panoply of hyperactivity, impulsivity and crazy energy a manifestation of some occult hypersensitivity reaction?

If so, they posited, then eliminating potentially offending foods from the diet of unmedicated children known to have ADHD should test this hypothesis. And, the converse should be true: re-introducing suspected foods after a period of avoidance should produce hyperactivity or inattentiveness in some or most kids.

As Pelsser explains during her NPR interview, the holy grail of therapy would be to develop a treatment for the cause of ADHD (say, food and diet) versus just treating the symptoms with medication. Pick up the binoculars, and look through the other end, right?

An excerpt on a nice overview by Kathleen Doheny on WebMD summarizes the study design thusly:

“Pelsser and colleagues assigned 100 children diagnosed with ADHD, ages 4 to 8, either to five weeks of the ADHD diet or to five weeks of following a healthy diet, with instructions on how to do so.

The ADHD diet was individualized for each child, eliminating foods that might cause problems. The diet was restricted to certain foods including rice, meat, vegetables, pears, and water, along with other foods such as potatoes, fruits, and wheat.”

And here, delivers the study’s punchline:

“In the ADHD diet group, 41 of 50 children finished the first phase. In that group of 41 children, 32, or 78%, responded favorably by having fewer symptoms. Overall, 32 of 50, or 64%, responded favorably… When the offending foods were reintroduced, symptoms returned in those who had responded favorably, the researcher says.”

It’s hard to read Pelsser’s paper, and to an extent, hear her interviewing on her research without getting fired up. Getting your paper published in the Lancet is a big deal, and being in that venerable journal’s table of contents suggests an author’s research has passed an especially tough level of peer review scrutiny. Good pedigree for her science. What’s more, Pelsser herself even asserts that some children’s symptoms were reduced so dramatically that they no longer need medication. And, by extension, she suggests we are probably overtreating kids with meds when their behavior challenges could be resolved by a change of what they eat. Geez, how and when can families eager to ditch the their Ritalin and Adderall start? Sign me up, doc.

I’ll bottomline my take on this compelling bit of work.

On the upside, Pelsser’s work is a thoughtful and intriguing first step in establishing the mind/body connection between diet and ADHD. A significant number of children with ADHD had measured improvements in their behavior and attention with a well supervised, elimination diet over a relatively short amount of time. Just 5 weeks! (and some commentators think even less time may be possible), And, Pelsser, et al’s study suggested nearly 80% of children who followed their restricted diet continued to do well.

On the downside, there are a few key details to work out. For one, the research gathered enough subjects to be statistically meaningful, but the data was only collected on one hundred Dutch kids. What would happen if we did this on 1,000, or a million? There are many issues to sort out, including how would these results look on a more diverse population. And, can this study design be scaled up and modified to work in the busy real world of pediatric primary care? It may take a while to provide a practical, evidence driven approach for clinicians and parents to follow. Is there a way of identifying these children after a diagnosis has been made? Not yet. Blood levels of immunoglobulins measured in the children in the Pelsser study for potential correlation with hypersensitivity to foods did not pan out as a useful tool…at this point.

Like any paper worth its mettle, Pelsser’s study calls for more research on the issue. We need to know more before we roll this out for everybody. For example, there may be cultural or religious or regional preferences which limit the appeal of diet based approach for this problem for some families. Five weeks is a long time. Will people commit? And, can lower income families afford healthier, pricier fare? (Based on the difficulty we’ve had in working with families with overweight children, I don’t think I can say that enough) Elimination diets require careful supervision and monitoring, such as frequent check-ins with a primary care doc or specialist, and work with nutritionists. Yet, for families with a bent towards natural or integrative therapies and/or who are less fond of medications, this may be just the ticket.

I am eager to see what comes next from colleagues, and from investigators who build on her paradigm-shifting, boundary-pushing assertion. I think we in medicine will do well to keep an open mind, to open the dialog with our families, and to take a fresh look to see if diet and nutrition are found to be contributors to, or even, causes of attention deficit, hyperactivity, or other behavior problems in some children. We’d best pay attention to the question of attention and what we eat. There may be a lot at steak!

Photo above by anarchy_emo_2008

Cartoon below by me

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