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How Does Diet Affect Symptoms of ADHD?

A simple diet improves ADHD symptoms in 60 percent of kids.

There is little argument that diet has a contribution in the major diseases of civilization, such as heart disease and type II diabetes. However, the effect of diet on mental health disorders remains controversial in the conventional circles. I'm not entirely clear why, as it has been known for a decade or more that different kinds of inflammation mediate both metabolic syndrome and the depressive disorders and schizophrenia. It seems logical to me to look for dietary or environmental insults that would predispose one to develop these disorders, and not just in fringe journals, or Australia.

But then, I also think it is logical that our immune systems are responsible for heart disease and high cholesterol, not that our livers (in a desperate effort to do us in) mastermind the release of cholesterol into the bloodstream to clog our arteries like an old sock dropped into the disposal. The reason I find the immune system to be a logical culprit is that the whole purpose of the immune system is to KILL THINGS and wreak havoc. Sometimes your armed forces turns tables on you - friendly fire, as it were. Did you know there are at least 48 different studies showing a correlation between low cholesterol and greater mortality in the elderly? Can you see why I at least question the idea of super low cholesterol as a laudable goal in light of the fact that our brains need lots of cholesterol and fat?)

ADHD in children. Controversial, of course, as stimulants are a primary treatment. The controversy looms large in part because behavior is primarily felt to be a parental/discipline problem. And there has always been the idea that "sugar" makes kids "hyper" - so we have this cultural meme of lazy parents and spoiled kids chowing down on skittles and garbage, driving the teachers nuts - the teachers, being lazy themselves, want the kids medicated into oblivion so that no one will have to do any work (especially, presumably, the psychiatrist, who happily prescribes addictive drugs in a 4 minute visit to keep the families coming back and to collect a large paycheck.) Do we really live in a world where everyone entrusted to keep our kids safe and happy is hopelessly lazy and corrupt? Because if the cultural meme is true, we are in deep trouble.

Let's get to reality, where families really suffer, and parents have tried everything, and teachers want kids to do better, and doctors try to spend some time in multifaceted ways to help. "ADHD" is a recipe list of symptoms - hyperactivity and inattentiveness being primary. Part of the issue is the silly recipe list - ADHD symptoms are a function of problems with the frontal lobe of the brain, and while several neurotransmitters are involved, an inefficiency of dopamine transmission may be the key player. And, indeed, there are some families with lots of ADHD who have known genetic issues with their dopamine receptors. There. Simple. It's dopamine. A kid has the symptoms, hand them dopamine in a ritalin tablet, and call it a day.

Not so fast. Problem is, a lot of different issues can cause problems with the frontal lobe and other associated ADHD areas, not just genetic issues. Depression, for one, seems to torch our ability to stay focused. So will anxiety. Lack of sleep (I'll be more specific about sleep and ADHD symptoms and defiant behavior in another post). Other kinds of inflammation. Issues with a thinning frontal cortex in development. The vulnerability to the different insults will be genetic, and families in general face similar environments, so a family with lousy sleep or lousy eating habits might all turn up with ADHD symptoms, just like the family with the primary dopamine problem. Stimulants will generally help perk up the frontal lobe and behavioral changes will help too, regardless of the cause - but one never wants to ignore an ongoing environmental insult that is damaging the brain while you correct the symptoms with a band-aid.

The stakes are high. Kids with ADHD are much more likely to grow up and get divorced, lose jobs, be in car accidents, and commit felonies. We don't want to dismiss the biology of the problem as non-existent and focus entirely on behavioral treatments, but we also don't want to throw ritalin at every kid who spazzes out in school. It's a complex issue, a complex and multifaceted disorder, and for a while now I have suspected dietary causes to be the problem for some kids. I've even written articles about it a couple times - mostly reviewing the work of a British group who did a well-designed study of 300 some-odd kids in 2007 called the Southampton Study.

In short, the researchers gave kids in the community (so just a random sample of kids, not particularly any diagnosed with ADHD, though some of them may have been diagnosed with it), in blinded crossover fashion, placebo drinks or two types of food additive drinks, with washout periods in between drink trials. Kids on the additive-laden drink were significantly more hyper in the reviews of parents, teachers, and independent observers. The additives were food colorings and preservatives that would be easy to find in a lot of brightly colored "food" marketed for children. It is the kind of study that should really make your ears perk up - sure, it ought to be repeated, but the results were pretty definitive. In fact, after this study came out, there were calls for voluntary bans on the use of artificial colorings in Europe. (When I talk about conventional medicine's lack of support for the idea that diet could possibly be related to mental illness, the title of an article in Harvard's Mental Health Letter in June 2009, two years after the Southampton Study, was "Diet and Attention Deficit Hyperactivity Disorder - Can some food additives or nutrients affect symptoms? The jury is still out.").

Well, the British researchers continued to dig deeper into the results of the Southampton Study, and in 2010 they published another study in The American Journal Of Psychiatry (these guys do great work, and get their stuff published in all the premier journals). I wrote specifically about it here - ADHD, Food Additives, and Histamine. Again, in short, the researchers checked out the genetics of the same kids from the Southampton Study, and found that kids who were made more hyper by the food additives were significantly more likely to have certain problems with genes regulating their histamine system. Anyone who has ever taken a benadryl for swollen eyes and a runny nose on a pollen-laden spring day will know what histamine is, more or less. Our bodies release it in response to some sort of allergenic stimulus. I made the point in my blog that the Southampton study seems to show us that, indeed, in some children (not all!), ADHD symptoms are a food allergy.

In February of 2011, another excellent study was published in The Lancet that took the next logical step of scientific exploration. There is also an editorial. (Neither are free full text, unfortunately, though they are available for purchase.) The INCA study is Belgian, and involved a randomized controlled trial with an open label phase (looks like it was single-blinded) followed by a double-blind crossover trial of an elimination diet vs. a "healthy diet" (control). The 100 children studied were were 4-8 years old and did have a diagnosis of ADHD.

The results were pretty astonishing (well, maybe not to me, or to a lot of parents, but to the diet skeptics out there, it should be pretty darn astonishing). Nearly two-thirds of the kids on the elimination diet for 9 weeks experienced significant reduction in ADHD symptoms and oppositional defiant behavior. The symptoms returned when the kids went back to the "healthy" control diet (which is a Belgian equivalent of the USDA diet recommended for children).

The treatment diet was simple - it was restricted to rice (some might avoid white rice for the excess carbohydrate with little other nutrient value, but most will agree it is essentially toxin-free and not objectionable "safe starch"), meat, vegetables, pears, and water. There was a less strict diet where small amounts of potatoes, wheat, and other fruits were allowed but by the end of week 2 of the diet, 41% of the kids had no response to the less strict version and were placed on the stricter diet.

There were a couple of interesting wrinkles. The kids were all tested for IgG antibodies to food, supposedly helping one sort out food intolerances. These tests are widely used by para-professionals to diagnose food allergies, but when you get down to it, there is not a lot of evidence these tests tell you much about what you might actually be allergic to. IgG antibodies simply mean that somewhere along the way your bloodstream was exposed to food allergens. To be honest, I think people with tons of positive IgG food allergies have leaky guts, that wheat and poor gut biome are reasonably likely culprits, and the foods that show up in the IgG test are a random sampling of what happened to make it through the leaky gut. In the INCA study, the kids were carefully rechallenged with their IgG + foods, and their symptoms of ADHD seemed to have nothing to do with the IgG test. So I'm right ;-) (maybe).

A quote from the Medscape article summarizing the findings and the editorial:

Dr. Pelsser's team concludes that a strictly supervised restricted elimination diet "is a valuable instrument to assess whether ADHD is induced by food, [but] the prescription of diets on the basis of IgG blood tests should be discouraged."

In her [editorial], Dr. Ghuman notes restricted elimination diet studies are "complex and challenging." The INCA study was "well-designed and carefully done, showed a benefit with a supervised elimination diet, and provides an additional treatment option for some young children with ADHD. "For interested parents," Dr. Ghuman told Medscape Medical News, "clinicians should encourage them to seek the advice of the child's primary care provider and a nutritionist for appropriate monitoring of the child's nutritional status and needs. The parents will need appropriate guidance and supervision for a structured protocol to determine any benefit and identify incriminated foods."

So more evidence piles up. In fact, the same researchers ran a pilot randomized controlled trial with 27 kids published in 2009 (free full text this time) and found that 11 of 15 children on the study diet improved by at least 40%, whereas none of the 12 kids on the control diet improved.

I may not be completely off base with my basic premise after all. I may disagree with the experts on what, exactly, constitutes a healthy diet, but there is little question in my mind that a healthy diet based on evolutionary theory and sound scientific principles and common sense will go a long way help you, and me, and our kids, be more resilient and more able to handle our frantic modern lives.

By the way, I am honored to have been asked to present some of my ideas at the Ancestral Health Symposium in August at UCLA. The event is sold out, but the talks will be available online also. I'll let you know more details as the weeks unfold.

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More articles like this one at Evolutionary Psychiatry.

Copyright Emily Deans, M.D.