ADHD and Diet: What the Research Tells Us
The idea that diet could affect ADHD symptoms became popular back in the 1980s. Since that time, many different diets have been studied to find out if, indeed, the type of food you consume can contribute to ADHD symptoms.
Here are some updates on what research shows us about how diet might affect ADHD:
The Feingold diet
The Feingold diet, named for the late Califonia pediatric allergist, Dr. Ben F. Feingold, eliminates additives, preservatives, and salicylates from your diet. Feingold's work as a pediatrician during the 1960's when food additives and preservatives populates supermarket shelves led him to his hypothesis on diet and disease. Presenting his research to the American Medical Association in the 1070's, Feingold asked that this hypothesis be tested, spawning the Feingold Diet - which later went mainstream. At that time, some doctors reported an extraordinary improvement in over 50 percent of the children who were switched to this diet. Later, controlled studies failed to find the same results, although researchers do accept that a small subset of children might be helped by following the restrictive diet.
Also known as an oligoantigenic diet, an elimination diet is based on the idea that food sensitivities can cause behavioral problems. Common foods eliminated from diets include cow’s milk, cheese, wheat cereals, eggs, chocolate, nuts, and citrus foods. Because skin allergy tests have proved unreliable for food sensitivities, foods must be completely eliminated and then added back, one at a time, to find which foods are causing a problem.
The diet is time-consuming and can be difficult to implement because you must wait several weeks after introducing each food to determine if there is a change in behavior. Studies have shown that some children benefit from eliminating certain foods. However, one 2012 meta-analysis of 34 sutides, published in the Journal of the American Academy of Child and Adolescent Psychiatry found 30 percent of children had a positive outcome. About two-thirds of those children had a relapse of symptoms when the diet was discontinued.
A number of studies were conducted on the effect of sugar on hyperactivity in children in the late 1980s and early 1990s. According to those studies parents reported more hyperactivity after their child consumed sugar. However, scientific studies did not support this. A meta-analysis of 16 studies, “concluded that sugar does not usually affect the behavior or cognitive performance of children, but a small effect on subsets of children cannot be ruled out.”
Omega 3 and Omega 6 supplements
While studies have shown some improvement in ADHD symptoms when children were given Omega 3 or 6 supplements, the results have not been conclusive. The improvements have not been sufficient to warrant no longer using medication, and it is still not clear what dosage [of the supplements?] is best.
Some studies have shown a correlation between zinc deficiencies and ADHD symptoms. Most of these studies, however, have been performed in the Middle East, where zinc deficiencies are more common. [NOTE: More common than where? The US and Europe?] One study completed in the United States did show an improvement in inattention symptoms but not in hyperactivity. Zinc supplements may also improve the benefit of stimulant medications, allowing for a reduction in daily dosages.
Western diet vs. healthier diet
A study in Australia looked at the difference in ADHD diagnoses in children who ate a Western diet compared to those who ate a healthy diet. A Western diet is described as higher in total fat, saturated fat, refined sugar and sodium and deficient in omega 3 fatty acids, fiber, and folate. A healthy diet is described as rich in fish, vegetables, fruit, legumes, and whole grain foods. In this study, children who ate a Western diet were more likely to be diagnosed with ADHD. However, the researchers did not look at other factors, such as family environment and emotional stress levels, which could also contribute to higher ADHD like symptoms.
Adults with ADHD and parents of kids with ADHD look to diet and other alternative treatments for a variety of reasons. Some people might not tolerate traditional ADHD medications, some might have a preference for more natural treatments and some might not receive any benefit from the medications, at all. Experimenting or changing your own or your child’s diet is no small feat. It takes time, patience, and persistence and can cause problems when other family members are affected, as well. There's also a good chance you'll need to try different diets, to find the one that works best for you or your child. However, research has certainly found that some people showed improvement in ADHD symptoms based on a change in diet.
Marine omega-3 polyunsaturated fatty acids induce sex-specific changes in reinforcer-controlled behaviour and neurotransmitter metabolism in spontaneously hypertensive rat model of ADHD: BioMed Central
Research review: the role of diet in the treatment of attention-deficit/hyperactivity disorder an appraisal of the evidence on efficacy and recommendations on the design of future studies: Journal of Child Psychology and Psychiatry