It stands to reason that an adequate diet is necessary for a child’s healthy growth. Proper nutrition, including an array of vitamins, minerals, amino acids, and essential fatty acids (EFAs), is particularly necessary in the first few years of life to support brain development and prevent certain neurologic disorders. Even among older children, a lack of certain dietary components, such as protein, or an insufficient number of calories can negatively affect a child’s learning and behavioral abilities, and vitamin or mineral deficiencies can certainly interfere with learning over the course of a school year. To date no convincing evidence has shown that a poor diet causes ADHD, or that dietary supplements can be used to successfully treat the condition. Nonetheless, healthy eating and family meals are lifestyle choices generally supported by the American Academy of Pediatrics (AAP).
In the 1950s Drs Abram Hoffer and Humphry Osmond began using megavitamins containing large amounts of vitamin B3, vitamin C and, later, pyridoxine (vitamin B6) to treat schizophrenia. This treatment was based on the theory that schizophrenia and some other forms of mental illness are caused by a genetic abnormality that greatly increases the body’s vitamin and mineral requirements. By providing patients with enormous doses (megadoses) of these substances, Hoffer and Osmond felt that psychiatrists could provide an “optimum molecular environment for the mind” in which the symptoms of mental illness would diminish or disappear.
In the 1960s the chemist and Nobel Laureate Linus Pauling put his support behind this theory, giving it the name orthomolecular psychiatry and greatly increasing its visibility among experts and the general public. In the 1970s Dr Allan Cott claimed that hyperactivity and learning disabilities were also the result of vitamin deficiencies and could be alleviated with megavitamins and large doses of minerals. Treating ADHD symptoms in children with nutritional supplements—supplements that contained at least 10 times the recommended daily allowance of vitamins, minerals, and other necessary elements—became an increasingly popular alternative to stimulant medication, particularly among families who considered megavitamins the more “natural” approach.
Research has failed, however, to reveal significant positive results from megavitamin therapy for children with ADHD. While some early studies resulted in improved classroom attention ratings for subjects taking megavitamins, these studies were marred by the fact that the children, their parents, their teachers, and the researchers were all aware that a given subject was being given this new form of treatment. When the studies were repeated using the double-blind method discussed earlier, so that no one knew whether a particular child was taking a megavitamin or a placebo, no behavioral improvement was shown. In fact, it was discovered that disruptive behavior increased in a significant number of the children given the megavitamins.
Studies have also suggested certain abnormalities in the way the liver functions among children on megavitamin therapy, signaling possible toxic effects of this high level of vitamin intake—a strong reminder that “natural” substances are not always safe, especially in the highly “unnatural” doses prescribed here. As a result, experts have concluded that megavitamin therapy for ADHD is of little benefit for nearly all children with the condition—and potentially harmful. In 1976 the AAP Committee on Nutrition issued a formal statement to that effect. No subsequent studies have provided evidence that would change this opinion. This is not to say that children with ADHD should not take any vitamins, just that vitamins at normal doses and even megadoses are not in any way an effective treatment for ADHD.
Other Vitamin and Mineral Supplements
In the wake of the enthusiasm for megavitamin therapy, a number of specific nutritional elements have been studied regarding their possible role in the development of ADHD and their potential for treating the condition. These elements include iron, magnesium, pyridoxine (vitamin B6), and zinc.
All of these substances are known to be necessary for optimal brain development and function. However, no difference between children with or without ADHD has been shown for levels of zinc, iron, magnesium, or vitamin B6, and no links between these low levels and ADHD-type behavior have been established to date. No significant improvement in ADHD behaviors has been demonstrated when supplemental doses of these substances are provided. As with all children, any true nutritional deficiency should be corrected with a standard supplement or a change in daily diet. But supplementation should not exceed the daily recommended allowance because higher levels of some elements (zinc in particular) can prove toxic.
Additional Supplements to Improve Performance
A number of other dietary supplements have been proposed to replace the use of stimulants in treating ADHD. Principal among these are nootropics, antioxidants, and herbs. Nootropics, specifically a substance called piracetam, have been advocated as cognitive enhancers for children with Down syndrome, dyslexia, and ADHD. While there is no scientific proof of positive effects relating to Down syndrome, one convincing study did show improvement in reading ability and comprehension among children taking piracetam supplements. While there is a rational basis for theorizing that piracetam may also improve ADHD-type behaviors because it is believed to enhance the transmission of the same brain chemicals influenced by stimulant medication (dopamine and noradrenaline), no controlled studies have yet been published, so this treatment cannot be recommended.
Children with ADHD as well as people who eat a modern American diet may have low levels of certain EFAs (including EPA and DHA). In a study of nearly 100 boys, those with lower levels of omega-3 fatty acids had more learning and behavioral problems than boys with normal levels. Studies examining whether omega-3 fatty acids can help improve symptoms of ADHD have found mixed results. A few studies have found that omega-3 fatty acids helped improve behavioral symptoms, but most of these were not well designed. One study that looked at DHA in addition to stimulant therapy found no effect. More research is clearly needed, but for now eating foods that are high in omega-3 fatty acids is certainly a reasonable approach.
Deanol (DMAE), lecithin, and phosphatylserine are other cognitive enhancers (nootropics) frequently found in over-the-counter ADHD remedies available in health food stores or on the Internet. Lecithin and phosphatylserine have not yet been sufficiently studied as treatments for this condition, but DMAE has seemed in one reliable study to be as effective as the stimulant methylphenidate in treating target behaviors. It is clear, then, that though these nootropics cannot currently be recommended as a substitute for stimulants due to insufficient evidence, they are currently being researched and warrant further study as a potential future treatment or complementary supplement for the symptoms of ADHD.
Antioxidants and herbs, used for many centuries in traditional medicine, have only recently come under scientific study. Some of the substances that have been marketed as treatments for ADHD include pycnogenol, an antioxidant derived from pine bark; melatonin, another antioxidant known to successfully treat sleep cycle disturbances in certain children; gingko biloba extract, often used in Europe to treat circulatory and memory disorders; and such herbs as chamomile, valerian, lemon balm, kava, hops, and passion flower. While melatonin can be useful in addressing sleep disturbances in a child with ADHD, and the herbs mentioned may also be useful as mild sleep aids, the reported positive effects of these antioxidants and herbs as treatments for ADHD core symptoms have been solely anecdotal so far, and there is insufficient scientific evidence to support their use.
If you do decide to administer any of these substances to your child, it is important to inform your child’s pediatrician and then carefully monitor their use because some can lead to harmful effects if used in combination with other medications. Gingko biloba extract, for example, must not be taken with aspirin, anticoagulants, or antidepressants, and the herbs listed should not be used when taking sedative medications due to the danger of compounding the sedative’s effects. It is necessary to keep in mind that these substances can vary considerably in potency from one preparation to another, and that they are not standardized or regulated by the US Food and Drug Administration.
Other theories about the causes of, and treatment for, ADHD have evolved from the hypothesis that certain substances that are present, rather than absent, in a child’s diet may lead to or worsen the condition. The suspected harmful substances include artificial food additives, preservatives, sugar, or other elements speculated to cause allergic responses or yeast infections that can lead to the development of ADHD. According to these theories, eliminating such elements may eliminate or diminish the symptoms of ADHD.
In the mid-1970s a groundswell of concern about the effects of food additives, artificial flavorings, and dyes in the American diet accounted for, in part at least, to the huge popularity of the Feingold Diet as a treatment for ADHD. Dr Benjamin Feingold, a practicing allergist, theorized that these food additives, as well as substances called salicylates (contained in many fruits and vegetables), were causing hyperactivity and learning disabilities in many children.
In his book, Why Your Child Is Hyperactive, Dr Feingold claimed that when these children were given a special “elimination diet” that omitted these substances, half of them showed a dramatic improvement in behavior. When the elements were reintroduced into the children’s diet, the symptoms returned. Most controlled studies do not support that elimination of these substances leads to better outcome for children with ADHD. Only about 2% of children with ADHD on the Feingold diet have shown consistent behavioral improvement when these food dyes were eliminated. However, reduction of processed foods that contain artificial dyes and substitution of healthy foods may in general promote better long-term health. Moreover, the behavior management strategies that parents must use to change a child’s eating behavior from frequent use of candies and processed foods to healthy choices are the same techniques that are used to improve concentration and increase work production.
Diets Eliminating Sensitizing Food Substances
In the decades since the Feingold Diet was introduced, studies of the impact of diet on behavioral disorders have become more sophisticated and reliable. Newer research has shown that behavioral improvement using elimination diets is more likely in children who have inhaled and food allergies, a family history of migraines, and food reactivity. Younger children seem to be the most responsive. Whole foods like milk, nuts, wheat, fish, and soy have been implicated in addition to additives. Elimination diets can sometimes influence sleep and mood disturbances as well as ADHD symptoms. Sensitivities to substances in the environment—in medicines, clothes, water, our homes, the air, and so on—have also been studied as they relate to children’s health and behavior. The results have shown a link between sensitizing foods and some health and behavior problems in a small percentage of children with ADHD. In most cases, these children experience a variety of coexisting health and behavioral difficulties in addition to ADHD—particularly sleep-related and neurologic problems. They are also likely to have a family history of food sensitivities or migraine headaches.
Because this link has been established, if food or additive sensitivities are highly suspected in your child, he may be tested for them by first eliminating an entire range of common foods (typically milk, soy, wheat, corn, citrus, and peanuts) for 2 to 4 weeks. If his symptoms improve—signaling the possible presence of a food sensitivity—the range of foods can be restored to his diet, then one food at a time can be removed for a short period, with the results being monitored. This process can continue until the correct substance has been identified or all likely possibilities have been exhausted. This procedure may be difficult to carry out, and it is advised that if you are interested you should do this along with a physician or certified dietician. It is extremely important to pick countable targets (such as “2 or fewer tantrums per day”) rather than general impressions (“will demonstrate better behavior”).
Meanwhile, it is important to understand that for most children with ADHD who do not have food sensitivities (and for some who do), elimination diets are not effective treatments for ADHD itself. If your child is on a special diet, you will need to make sure it is not replacing a more effective treatment for ADHD symptoms. In most cases, stimulant medication,behavior therapy, and the other measures described in previous chapters will have a much clearer positive effect on your child’s ADHD-related behaviors, while a well-balanced diet with few processed foods may improve his general health and attitude.
Humans are naturally attracted to sugar because it tastes good and because our bodies rely on glucose—the form of sugar found in natural foods—for metabolic processes. Like many other children, children with ADHD often have strong sugar cravings, and this has contributed to the belief that sugar and candy consumption can cause hyperactive behavior. A great deal of objective evidence, however, has shown that this assumption is untrue for most children with or without ADHD. While one early study did reveal a link between high sugar consumption and hyperactive behavior, there was no evidence that one caused the other or that the behavior problems were not due to different parenting styles or other factors. A number of subsequent scientifically rigorous studies could not demonstrate any adverse effects of sugar on the behavior of children. As for children with ADHD, sugar consumption has not been shown to cause or enhance ADHD-related behavior.
Of course, allowing sugar only in moderation makes sense for any child. Again, assuming leadership within the family, making healthy choices about what is offered to the child, and using behavior management to educate children to reduce sugar and processed food may have general benefits. If your child shows an uncontrollable craving for sugar and carbohydrates, discuss this with his pediatrician. Aside from issues relating to general health, a sugar-free diet is not considered a useful tool in treating ADHD. Researchers have found again and again that the simple elimination of sugar or candy, with few exceptions, does not help children with ADHD.
Aspartame, an artificial sweetener that became available in the early 1980s, consists of amino acids that cross from the bloodstream into the brain to affect brain function. (Interestingly, it was used as the placebo in some of the studies of sugar’s effects on behavior.) It was believed that among individuals susceptible to this substance, aspartame might lead to seizures or ADHD-type behaviors. No such effects have been demonstrated, however, and elimination of aspartame for children with ADHD is not considered an effective treatment except for children with phenylketonuria, a chemical disorder that prevents some people from being able to break down or metabolize aspartame.
Yeast- or Fungus-Free Diets
In the mid-1980s, Dr William Crook, a practicing pediatrician and allergist, popularized the theory that hyperactivity, irritability, and learning disorders in children could be caused by chronic candida (yeast) infection. The theory behind this is that when the immune system is weakened, or when antibiotics are being taken, “friendly” bacteria in the gastrointestinal system are eliminated and yeast can take over. Those who feel that this process has a deleterious role in children with ADHD believe that toxins produced by a yeast overgrowth weaken the immune system and make an individual susceptible to ADHD. Because of this they support the use of antifungal agents and sugar restriction. There are no sound studies that support this hypothesis or this treatment.