As previously mentioned, ADHD is most likely caused by multiple factors, including nutritional issues. Children with ADHD may have specific nutrient deficiencies that aggravate their condition. As researchers learn more about the intersection between diet and behavioral disorders, the case for nutritional intervention among children with ADHD becomes more compelling. In the future, it is almost certain that this multifactorial disease will be treated on multiple fronts, including nutritional intervention (Harding 2003). Already, many progressive parents and physicians are turning to comprehensive health care options to battle this frustrating condition.
Essential fatty acids. A growing body of scientific literature is helping parents and doctors better understand the link between fatty acids and behavioral disorders such as ADHD. The ratio between omega-3 and omega-6 fatty acids (e.g., arachidonic acid) seems especially important. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are omega-3 fatty acids found in flaxseed oil and cold water fish. In the typical Western diet, we tend to consume more omega-6 fatty acids relative to omega-3 fatty acids. The ratio of omega-3 to omega-6 fatty acids has been shown to influence the development of neurotransmitters and other chemicals that are essential for normal brain function. Increased intake of omega-3 fatty acids has been shown to reduce the tendency toward hyperactivity among children with ADHD (Haag 2003).
Several studies have examined the role of essential fatty acids in ADHD, with very encouraging results:
- In one pilot study, children with ADHD were given flaxseed oil, which is rich in alpha-linolenic acid. In the body, alpha-linolenic acid is metabolized into EPA and DHA. At the end of the study, researchers found that the symptoms of children with ADHD given the flaxseed oil improved on all measures (Joshi 2006).
- Another study examined the effects of flaxseed oil and fish oil, which provide varying degrees of omega-3 fatty acids, on adults with ADHD. The patients were given supplements for 12 weeks. Their blood levels of omega-3 fatty acids were tracked throughout the 12 weeks. Researchers found that high-dose fish oil increased omega-3 fatty acids in the blood relative to omega-6 fatty acids. An imbalance between arachidonic acid and omega-3 fatty acids is considered a risk factor for ADHD (Young 2005).
- Finally, one study compared 20 children with ADHD who were given a dietary supplement (that included omega-3 fatty acids) to children with ADHD who were given methylphenidate. The dietary supplement was a mix of vitamins, minerals, essential fatty acids, probiotics, amino acids, and phytonutrients. The groups showed almost identical improvement on commonly accepted measures of ADHD (Harding 2003).
One study has also indicated that children with ADHD benefit from the intake of a combination of essential fatty acids and vitamin E (Stevens 2003).
Magnesium and vitamin B6. Combining magnesium and vitamin B6 has shown promise for reducing symptoms of ADHD. Vitamin B6 has many functions in the body, including assisting in the synthesis of neurotransmitters and forming myelin, which protect nerves. Magnesium is also very important; it is involved in more than 300 metabolic reactions. At least three studies have demonstrated that the combination of magnesium and vitamin B6 improved behavior, decreased anxiety and aggression, and improved mobility among children with ADHD (Nogovitsina 2006a,b; Nogovitsina 2005; Mousain-Bosc 2004).
Iron. Iron deficiency may be implicated in ADHD (Konofal 2004), although supplementation studies have shown minimal or no effects (Millichap 2006). Because of the potential toxicity of iron supplements, parents should consult their children’s pediatrician before beginning supplementation.
Zinc. Zinc is a cofactor for the production of neurotransmitters, fatty acids, prostaglandins, melatonin, and indirectly affects the metabolism of dopamine and fatty acids. However, the role of zinc in ADHD is still emerging. While numerous studies have shown that children with ADHD are often deficient in zinc, researchers have not determined that a zinc deficiency causes ADHD or that treatment with zinc can improve symptoms of ADHD (Arnold 2005a,b). Two Turkish studies, however, have tested zinc therapy among children with ADHD with positive results. In these studies, children were randomized to groups that received either zinc or placebo. In one study, the conditions of children who took zinc for 6 weeks improved (Akhondzadeh 2004). In the second study, zinc as the sole therapy resulted in significant improvements compared to placebo (Bilici 2004).
Acetyl-L-carnitine. Acetyl-L-carnitine, a form of L-carnitine, is responsible for transporting fatty acids into the mitochondria. It has been associated with a host of positive health benefits, including reducing impulsivity. In an animal model of ADHD, acetyl-L-carnitine was shown to reduce the impulsivity index (Adriani 2004).
Phosphatidylserine. Phosphatidylserine, a critical component of cell membranes, plays a role in nerve cell signaling. Phosphatidylserine has been found to improve memory and concentration in adults (Kidd 1999); one report found it significantly improved attention and learning in children with ADHD (Kidd 2000).
Neurotransmitter support. A new technique related to magnetic resonance imaging (MRI) is proton magnetic resonance spectroscopy (1H-MRS), which reveals important information about chemical compounds in different brain areas.
Recent studies using 1H-MRS suggest that choline, creatine, glutamate, and other specific compounds may play a role in ADHD. Choline is one of the building blocks of acetylcholine, an important neurotransmitter involved in memory. Glutamate and glutamine are amino acids involved in the production of GABA (gamma-aminobutyric acid), a neurotransmitter that inhibits certain nerve impulses and may affect hyperactivity.
In one study, 1H-MRS analysis showed that children with inherited and structural features linked to poor memory had lower concentrations of creatine-phosphocreatine and choline-containing compounds, whereas creatine and N-acetyl aspartate were associated with good memory, reflecting differences in energy metabolism in the frontal lobes of the brain (Yeo 2000).
However, a 1H-MRS study of ADHD showed a mild increase in the ratio of choline to creatine on one side of the striatum, a deep brain region in which about one quarter of the nerve cells were lost or severely dysfunctional. The investigators concluded that neurotransmission involving acetylcholine was mildly hyperactive (Jin 2001).
In another 1H-MRS study, eight children with ADHD but without learning disabilities had increased glutamate-to-glutamine ratios in both frontal areas, and increased N-acetyl aspartate and choline in the right frontal area, compared to eight controls (Courvoisie 2004).
Investigators from Venezuela found diminished blood levels of the amino acids glutamine and phenylalanine in ADHD patients. They hypothesized that this imbalance could cause alterations in amino acid metabolism and transport to the brain, which might alter central nervous system function. Their findings support the theory that ADHD represents a disorder of the inhibitory neurotransmission system (Zavala 2001).
Choline supplementation is theoretically more beneficial for diminished memory and learning than for other ADHD symptoms (e.g., hyperactive and impulsive behavior). Choline has an unpleasant taste, so children may prefer DMAE (dimethylaminoethanol), a supplement that increases brain levels of choline (Jope 1979). DMAE may speed up production of acetylcholine in the brain, and has been used to treat reduced attention span, learning and reading problems, hyperactivity, and poor coordination associated with ADHD (Dean 1990; Lewis 1975).
Additional Nutrients And Hormones
Melatonin. Melatonin is a hormone secreted at night by the pineal gland. It participates in multiple body processes, including regulation of the sleep/wake cycle. Because many children and adults with ADHD also have sleep problems, melatonin can be an important part of integrative therapy. By some estimates, up to 25 percent of children with ADHD also have sleep disorders. However, conventional therapy treats hyperactivity but neglects the sleep disorder (Betancourt-Fursow de Jiménez 2006). In one study of 27 children with ADHD and insomnia, 5 milligrams (mg) of melatonin, combined with sleep therapy, helped reduce insomnia (Weiss 2006).
Dehydroepiandrosterone (DHEA). DHEA is an important neuroactive steroid hormone that may be involved in ADHD. However, researchers are still trying to understand the relationship. ADHD is associated with low blood levels of DHEA, its principal precursor pregnenolone, and its principal metabolite dehydroepiandrosterone-sulfate (DHEA-S). Higher blood levels of these neurosteroids are associated with fewer symptoms (Strous 2001). Furthermore, a study of adolescent boys with ADHD showed that DHEA levels rise after a 3-month course of methylphenidate treatment, which implies that DHEA somehow plays a role in the drug's effectiveness (Maayan 2003).
Ginkgo biloba and ginseng. A combination of ginkgo biloba and ginseng has been studied for its ability to improve symptoms among patients with ADHD. In a study of 36 children ranging in age from 3 to 17 years, a combination of Ginkgo biloba and American ginseng was administered twice daily on an empty stomach for 4 weeks. At the end of the study, more than 70 percent of patients had experienced improvement on a widely used measure of ADHD symptoms (Lyon 2001).
L-theanine. Research has shown that the amino acid L-theanine, found in green tea, is more effective than a common prescription drug in promoting relaxation by increasing levels of serotonin and dopamine, and blocking the binding of L-glutamic acid to glutamate receptors (Lu 2004; Nathan 2006; Yokogoshi 1998).
Pycnogenol. A few case studies suggest that some ADHD patients may benefit from pycnogenol, an extract of French maritime pine bark and a potent antioxidant, which supports blood vessel dilation and provides cellular protection (Rohdewald 2002). Children given a daily dose of 1 mg per kilogram of body weight (about 0.5 mg per pound) of this pine bark extract for four weeks showed significant improvements in multiple standard measures of ADHD (Trebaticka 2006).