Can eating—or avoiding—certain foods help calm down kids (and perhaps even adults) who have attention-deficit/hyperactivity disorder (ADHD)?

That’s a question that many people are asking, and a new analysis that reviewed 70 studies on the topic provides answers.

I’ve written before about the impact of diet on ADHD, but this meta-analysis of past studies by J. Gordon Millichap, MD, a neurologist at Children’s Memorial Hospital in Chicago, helped sort out what we might be doing to make this behavioral epidemic worse.

FOODS THAT HELP YOU FOCUS

Dr. Millichap and his colleagues reviewed studies dating back to the 1970s that analyzed several types of diets for children with ADHD, including…

  • The Restriction Diet. Limiting intake of sugar.
  • The Elimination Diet. Not eating entire food groups that are often implicated in food allergies, such as cow’s milk, cheese, eggs, chocolate, nuts and citrus fruits.
  • The Feingold Diet. Avoiding food containing preservatives and additives, such as dyes.
  • The Supplementation Diet. Adding more omega-3 and omega-6 fatty acids, such as through fish oil capsules.
  • The Western Diet. Eating standard American food, which is high in saturated fat, salt, refined sugars and omega-6 fatty acids.

The results? There was a clear winner, a clear loser and then a lot of mixed results in between.

The clear loser: Western Diet

No surprise here! Experts have been telling us for years that this diet is unhealthy for all people, and some research shows that it may be particularly harmful for those with ADHD and it may even be a catalyst for it starting in the first place. For example, one Australian study of kids up to age 14 revealed that those who consumed high amounts of fat, sugar and salt had a significantly greater chance of developing ADHD compared with those who ate diets rich in fish, vegetables, fruit, legumes and whole grains. Though he’s not exactly sure why, Dr. Milichap said that it may be related to an inflammatory process that unhealthy foods produce in the body.

Mixed Results: Restriction Diet, Elimination Diet and Feingold Diet.

For these three types of diets, some studies showed that they helped ease ADHD symptoms while others showed that these diets made ADHD symptoms worse, so it was impossible for researchers to draw a clear conclusion. One possibility for the mixed results, said Dr. Millichap, could be that all of these diets are particularly rigid—and since school-age children (especially adolescents) are often faced with poor food choices at school cafeterias and aren’t known for being especially responsible in any case, there’s a good chance that many did not adhere to these diets well enough or long enough to see any potential benefit.

The clear winner: Supplementation Diet

Listen up, because there was one method that came out on top—adding more omega-3 and omega-6 fatty acids to kids’ diets. Most Americans are deficient in omega-3s but get enough—some might even argue too much—of omega-6s, mainly from processed foods, so it’s likely that the key nutrient that made the difference here is the omega-3s, Dr. Millichap said, because they appear to be important in helping the brain regulate impulses.

An example: One UK study of 117 kids ages five to 12 found that those who ingested 732 mg of omega-3 and 60 mg of omega-6 fatty acids through daily supplements for six months had fewer bothersome ADHD symptoms and gained statistically significant improvements in reading and spelling scores and behavior when compared with those who took placebo supplements. Dr. Millichap’s advice: If your child has ADHD, ask your doctor whether he or she might benefit from a certain amount of omega-3 daily supplementation…or feed him or her more foods that are high in the nutrient, such as flaxseeds, walnuts, salmon and soybeans.

His research was published in the February 2012 issue of Pediatrics.

DIET ALONE WON’T HELP

It’s important to note, however, that none of the diets (even the Supplementation Diet) were as effective as ADHD medications in terms of improving symptoms, said Dr. Millichap. I know that may be disappointing news, since ADHD drugs—which are usually powerful Ritalin-based stimulants—are in short supply in many places in the US right now and carry concerns about loss of appetite and the rare occurrence of cardiac side effects. But according to Dr. Millichap, they are still a child’s best defense against the disorder even when symptoms aren’t severe. So if you’re going to adjust your child’s diet, Dr. Millichap said to make sure it’s in addition to whatever medications your child is already on—and not instead of, at least not at first. A better diet might not eliminate your child’s need for meds, but it could at least reduce the amount of meds that he or she needs—and that is a good first step.

While the studies that Dr. Millichap reviewed were all done on children and young adults with ADHD, he thinks that the results would likely hold true for adults with the condition, too—and that anyone who suffers from ADHD should consider either changing up what is served at mealtime or taking an omega-3 supplement.