Diet and ADHD - A Literature Review

Last Thursday I had to report for jury duty.  Fortunately my number was on the higher side, so it involved me sitting in a room for a while reading some papers while the slots for the criminal case were filled.  I'm glad I wasn't selected -- the case involved the deaths of small children in a fire.  Ever since I had a couple of my own small children, I find it much harder to be "clinical" about violence and death when it comes to kids.  I put down Blood Meridian five years ago and haven't picked it up since.

Grieg - Holberg Suite (Prelude)

One of the terrific articles released this month is The Diet Factor in Attention-Deficit/Hyperactivity Disorder, in Pediatrics.  A couple of neurologists culled the literature, including not only the modern work done in Australia, England, and Belgium, but also the old Feingold stuff from the 70s.  They offer both an historical and evidence-based perspective, which enables one to see not only the science, but the human story of dietary treatments for ADHD.  Let's dive in, as there is a lot to cover.

The paper begins with a brief overview.  Basically, when it comes to dietary treatments for ADHD, there isn't that much to choose from that has been studied.   We start with the old anti-salycilate Feingold approach (which also avoids other major allergens, such as food dyes and other additives.) The diet involves avoiding apples, grapes, lunch meats, and any foods containing artificial preservatives or dyes.   One could eat certain cereals, beef, lamb, pineapples, bananas, pears, grapefruit, milk, eggs, and color-free vitamins.  Enthusiasm for Feingold was huge in the 1970s, however, clinical trial results weren't as impressive as the case reports.  Occasionally, certain children would have an amazing response, but overall the treatment was not helpful to most.

After Feingold waxed and waned (20 articles in pubmed between 1979-1988, 2 between 1990-2010), a newer elimination diet approach has come to the fore (based on the Southhampton Study I've written about several times, with the follow-up INCA study that was quite impressive).  The theory behind these diets and Feingold is that ADHD behaviors are, for some, a display of intolerance to certain foods.  The Southamption study backed this theory up with some superfly demonstration that the kids who were sensitive to food dyes had histamine systems that seemed to be more brittle and less able to clear out junk than other kids.

Hypoallergenic diets are a version of your basic "paleo autoimmune" diet - no wheat, cow's milk, cheese, eggs, nuts, chocolate, or citrus fruits.  Hypoallergenic foods include lamb, beef, potato, tapioca, carrots, peas, and pears.  (Another example is a "few foods elimination diet" consisting of turkey, rice, pear, and lettuce, in which 62% of children had a >50% improvement in behavior on the diet).  In pilot studies and the larger INCA trial, these diets typically resulted in significant improvement in 60% of the children who tried them.

The problem with elimination diets is that they are tough.  You have to be very strict, and the whole family has to be on the same page.  With every Disney character advertising a new processed food these days, it is harder than you think to keep the kids' diet clean even for a short duration of an elimination diet trial.  I know when I show up at snack time at the preschool, most of the kids have spritely-colored gogurt and goldfish and juice boxes.   My poor children (who don't seem to have behavioral or attentional problems) are stuck with water, prissy whole milk straight from the dairy delivered in glass bottles, fruits, meats, home fries, mashed potatoes, stew, veggies, and if they are lucky, the occasional organic pudding, yobaby full fat yogurt, or gluten-free pretzels.  Frankly, the only way I get them to eat mostly healthy is by stuffing them full of good stuff first and bribing them with a small amount of bad.

BUT, considering that such diets, when done with care, are a relatively harmless maneuver, it seems worth trying. And considering that most of the moms I know seem to have at least one son with some real attention-related issues, I wish there were more public support for these diets.  One mustn't have the expectation that the diets are a cure all, however.  Typically, 40% of kids will not respond.

Grieg - Holberg Suite (Air) - Right click to open in new tab.  I do like this piece.  One of my all time favorites.

Besides elimination diets, supplements with iron, zinc, and omega 3 fatty acids have also been attempted in the treatment of ADHD.  Long chain omega 3 PUFAs are lower in the RBC membranes of kids with ADHD compared to controls.  Kids with ADHD may have low O3 intake as well as reduced conversion of other long chain PUFAs to the essential O3s.  In the Oxford-Durham study, kids with coordination problems were given supplements made of 80/20 O3/O6.  ADHD symptoms improved in most of the kids, whereas no change was found in the placebo group.  Spelling and reading gains were also substantial in the experimental group over the 3-6 month follow up.  There were no adverse effects.  These authors, reviewing the 16 studies over the years, recommend doses of 300-600mg daily of Omega 3 with no more than 30-60mg O6 in the supplements (nordic fishes chews, nordic gummy bears, megared krill oil, and nature made were some examples of supplements used.) The authors note that in their clinic, most parents are enthusiastic about using omega 3 supplementation, but in almost all cases, additional medication treatment is required for meaningful symptom improvement.

Zinc!  I like zinc.  And in studies in Turkey and the Middle East, kids with zinc deficiency tend to be more hyperactive.  These regions have endemic zinc deficiency, unlike the West in general.  In a few US studies, zinc supplementation enhanced the benefit from d-amphetamine medicine.  The optimal dose of stimulant was decreased by 30% when compared to placebo. Since zinc is a cofactor for the metabolism of many neurotransmitters and fatty acids, it would make sense that having zinc stores tip top would help in ADHD.

Iron - kids with documented iron deficiency or low ferritin do seem to have more problems with learning disorders and cognitive function (yes, your brain needs oxygen!), however, in a random sampling of kids with ADHD, ferritin and iron was no different than those of controls.  It makes sense to check for iron deficiency in kids with ADHD, nevertheless.

Ketogenic diets have not been studied in ADHD, though in kids with epilepsy, attentional and behavioral problems often improve on the ketogenic diet.

Finally - sugar.  Despite the sworn testimony of every parent and pre-school teacher everywhere, sugar has never been consistently shown to increase aggression or activity in children compared to placebo, aspartame, or saccharine.  However, there is some data to suggest a cranky downward hypoglycemic response in some sensitive children.  And while adults don't tend to show behavior symptoms at a blood sugar greater than 54, children consistently show changes on EEG and in behavior at blood sugar levels less than 75 mg/dl.  Such a level is easily obtained by giving kids sugar only, while protein and fat can smooth the sugar spike and hypoglycemic aftermath.

Grieg - Solveig's Song (also very pretty).

And finally, the authors of the paper give a shout-out to the Australian study showing a link between Western Diet and ADHD symptoms.  The diet pattern had a higher intake of "total fat, saturated fat, refined sugars, and sodium, and is deficient in omega 3 fatty acids, fiber, and folate."  The "Healthy diet pattern... is rich in fish, vegetables, fruit, legumes, and whole-grain foods."  Of course, a family eating ho-hos, icing, and cotton candy is going to be a different sort of family than the one who eats whole grains and fish.  However, I'm all in favor of reducing processed foods.  Duh.

And that wraps up the summary of the study of dietary factors and ADHD.  GAPS was not mentioned.  In general, I would say, avoid additives and processed food, make sure your kids are stocked up with minerals, and don't go nuts with the sugar.  Elimination diets to determine special food sensitivities or gut bacterial overgrowth problems would probably be more helpful than harmful.  Pick your battles, but good food is a worthy fight, I would say.

(A sublime soprano version of Solveig's song by Marita Solberg can be found here.  Chills.  And I'm a much bigger fan of orchestral music than opera.)