NPR reported today on a new study in The Lancet in which researchers examined whether dietary intervention can improve ADHD symptoms in kids. Researchers found a significant decrease in ADHD symptoms with the specific diet. Kids in the study ate an elimination diet primarily of rice, meat, vegetables, pear and water, although I was surprised to see they included some supplementary wheat as well.
This is not the first study of ADHD and diet. Another review of 35 years of dietary research suggested kids with ADHD are sensitive to artificial food colorings and preservatives, and that this sensitivity typically co-presents with sensitivities to milk, chocolate, soy, eggs, wheat, corn, legumes and sometimes grapes, tomatoes, and orange.
I’m curious about the inclusion of wheat in the Lancet study because there’s some interesting research about gluten and ADHD. Some of this research focuses on people with celiac disease specifically, such as one study of children and adults that suggested untreated celiac disease (e.g. people with celiac disease who still eat wheat, rye and barley) can manifest ADHD-like symptoms. In another, admittedly small study of children with autism, some of whom also had ADHD symptoms, researchers removed gluten and casein (which comes from dairy) from the diet and found significant improvement of ADHD symptoms among the ADHD subset.
But gluten can’t be the whole picture, as the newer study suggests. Of course, it’s rare that only one dietary component is responsible for large-scale effects on the body, even with obesity. I’d like to see more research on the role gluten plays.
For those who may have gluten intolerance and may not know it, it’s worth leaving gluten entirely out of your diet for a minimum of three weeks and seeing whether your health improves — you may see other surprising effects, like an improvement in lactose tolerance.
A friend asked me about sugars and ADHD. The research on this could be better, but it’s interesting. A lot of it seems to focus on short-term changes in symptoms instead of effects of a longer-term dietary change. One study showed significant immediate response of ADHD symptoms in kids fed sugars/high-carbohydrate breakfast. Another study found no significant effect of sugars or food dyes.
My guess is that sugars play a long-term role in worsening ADHD symptoms, and I’d like to see more research. I’d especially like to see fructose/high-fructose corn syrup examined in more detail, considering its unique relationship to changes in metabolism and weight (study – full text!). Also, trace mercury, which can also contribute to ADHD, has been found in HFCS (full text) .
The study uses an elimination diet, which grabs my attention more than many studies of association between diet and health problems. Nutritional epidemiology is notoriously difficult; even each of the standard means of measuring food intake has flaws. So what to do with this information? There’s a sub-camp of nutrition advocates who, in response to this kind of research, will say just, “It’s what we know; eat a diet of whole foods and you’ll be fine!” I don’t precisely agree with this. “Whole foods” is a very vague term, for starters, and has been co-opted as a marketing term. The attitude also doesn’t account for changes in the nutritional value of food from, say, changes in how we feed animals or treat soil. The attitude includes all “whole” grains, not accounting for some of the real health problems associated with gluten, or for historical changes in how societies treat grains (e.g. no longer soaking, sprouting or fermenting them).
But some of that general message is right, in that what people commonly refer to as whole foods don’t contain added sugars or dyes or preservatives. Still, I’d change the message to something like: Eat whole foods from animals raised on pasture and vegetables grown without pesticides. Avoid or limit gluten grains, and treat other grains traditionally. Limit the other stuff, and do what’s right for you.
And now, go ride bikes!
Thanks to citymama for the Creative Commons photo.