Potential Link Between Dietary Intake of Fatty Acids and Behavior: Pilot Exploration of Serum Lipids in Attention-Deficit Hyperactivity Disorder

Abstract

Essential fatty acids are structural components of all biological membranes and form the environment for membrane receptors, ion channels, and enzymes. Dietary linoleic acid is metabolized by delta-6-desaturase to gamma-Iinolenic acid (GLA). Through several further metabolic steps, GLA is eventually converted to series-1 prostaglandins, thromboxanes, and other molecules involved in regulating the moment-to-moment function of various physiological processes. For example, prostaglandins interact with dopamine neurotransmission. The biochemistry and physiology of essential fatty acids are reviewed, with attention to possible implications for behavior. Delta-6-desaturase deficiency has been hypothesized to be one cause of attention-deficit hyperactivity disorder (ADHD). To explore this possibility, we examined the correlations of serum lipids and behavior in a double-blind crossover comparison of GLA, d-amphetamine, and placebo in 16 boys (ages 6-12) with ADHD. Looking at the fatty-acid components of serum triglycerides across treatment conditions, we found that higher scores for behavior problems correlated with lower levels of GLA (for each of four behavioral ratings, p < 0.015) but not with its precursor, linoleic acid. This is compatible with a metabolic bottleneck at delta-6-desaturase being related to some ADHD symptoms. These preliminary findings are consistent with the possibility that fatty-acid intake or metabolism may influence behavior, at least in children with ADHD, and could conceivably modulate the effects of psychopharmacological treatment. This study must be considered exploratory and heuristic, and more definitive studies are needed to examine the possible relevance of fatty-acid metabolism to psychiatric disorders.Several possible mechanisms may link essential fatty-acid metabolism to behavior. These potential connections include not only the effects of general body metabolism on brain function, but also the structural need for polyunsaturated fatty acids in neuronal membranes and the influence of these fatty acids and their metabolic products on neurotransmitter production, release, and effects. This article will review the biochemistry and physiology of essential fatty acids, consider some suggestive animal behavior findings, focus more specifically on possible implications of gamma-linolenic acid (GLA) for attention-deficit hyperactivity disorder (ADHD), and finally present some relevant pilot data.

Significance of long-chain polyunsaturated fatty acids (PUFAs) for the development and behaviour of children

“…In these studies, fatty acids were administered individually or in combination, as monotherapy or as an add-on to existing pharmacotherapy. Early studies on the effect of the sole administration of the ω-6 fatty acid GLA to hyperactive and ADHD children established merely a minimal therapeutic benefit [3,6,7]. Likewise, the administration of ω-3 fatty acids in monotherapy form was ineffective.…”

The Impact of Polyunsaturated Fatty Acids in Reducing Child Attention Deficit and Hyperactivity Disorders

“…Arnold and colleagues (Arnold et al, 1989;Arnold, Kleykamp, Votolato, Gibson, & Horrocks, 1994) also expected supplementation with n-6 FA to demonstrate behavior improvement in ADHD children in whom a deficiency in Delta-6-desaturase was suspected. Arnold et al (1994) observed 18 boys with ADHD diagnosis in a double-blind placebo-controlled cross-over design. They compared n-6 FA supplementation (GLA: 320 mg, LA: 2,800 mg) with a drug (dextroamphetamine) and with a placebo.…”

Nutritional and Environmental Approaches to Preventing and Treating Autism and Attention Deficit Hyperactivity Disorder (ADHD): A Review

“…70 Another study involving 18 boys with ADHD reported that use of 4000 mg evening primrose oil capsules produced little improvement in ADHD symptoms as compared to placebo. 71 The only factor in this study to signifi-…”

“…71 Double-blind, placebo-controlled studies have reported that supplements of carnitine 72 and zinc 73,74 have been helpful in treating ADHD symptoms. Some studies have found that magnesium and vitamin B 6 supplements significantly reduce excitability and improve concentration in ADHD children.…”