Can Dietary Supplementation Compensate Fatty Acid Deficiency and Alleviate Disorders 

Fatty acid deficiencies and their related diseases have raised the possibility that dietary supplementation with highly unsaturated fatty acids (HUFA) might be of some benefit. ForADHD, several controlled trials have shown mixed results. Such studies provided supplementation with evening primrose oil containing omega-6 fatty acid GLA (Gamma-linolenic Acid) and indicated only marginal, if any clear, benefits. Recent research shows that omega-3 fatty acids are likely to be more important than omega-6 in their effects on behavior and learning.

In another randomized trial of fatty acid treatment for ADHD children, a supplement of fish oil and evening primrose oil was used. This supplement mainly contained omega-3 fatty acids (EPA and DHA) and a little omega-6 (AA and GLA). This study indicated blood fatty acid changes in the treated children were associated with reduced ADHD symptoms. But, supplementation with DHA alone was ineffective in treating ADHD. This is consistent with other evidence from other studies that reported EPA, not DHA, is more important omega-3 fatty acid for improving attention and mood and reducing perceptual or cognitive difficulties. 

In a small study with dyslexic children, results showed that compared with placebo treatment, highly unsaturated fatty acids (HUFA) supplementation for three months significantly reduced anxiety and disruptive behavior. When the placebo group was given highly unsaturated fatty acids (HUFA) (without the children or their parents and teachers being aware of the switch) they showed noticeable reductions in ADHD-related symptoms over the next three months. In a separate larger study with dyslexic children, highly unsaturated fatty acids (HUFA) treatment has been shown to improve reading skills.

A study with dyspraxic children, which used supplementation with both omega-3 and omega-6 highly unsaturated fatty acids (HUFA) for three months from a combination of fish oil and evening primrose oil, showed reductions in motor difficulties and ADHD symptoms.

Recent researches have also found roles of fatty acids in adult psychiatric conditions. The omega-3 fatty acids appear to be a very promising new line of treatment for psychiatric conditions. The benefits of omega-3 supplementation have been shown in various studies. Such supplementation has been helpful in treating schizophrenia in controlled trials, bipolar (manic depressive) disorder, and most recently, treatment-resistant depression.

Biochemical and behavioral abnormalities could partially be alleviated by a dietary phospholipid supplement, especially omega-3-rich egg yolk extracts or pig brain. A study has shown that animal phospholipids are more effective than plant phospholipids to make up the ALA deficiency, partly because they provide very long preformed chains. Dietary omega-3 fatty acids play a role in the prevention of some disorders including depression, as well as in dementia, particularly Alzheimer's disease. In studies involving dietary intake of omega-3 fatty acids, it has been shown that the nature of polyunsaturated fatty acids (in particular omega-3) present in formula milks for infants (both premature and term) determines the visual, cerebral, and intellectual abilities.

In a recent study, a US research team has shown that DHA may slow the growth of two brain lesions that are hallmarks of Alzheimer’s disease. This study with genetically modified mice is first to show that DHA can slow the accumulation of tau, a protein that leads to the development of neurofribillary tangles. Such tangles are one of two signature brain lesions of Alzheimer’s disease. DHA also was found to reduce levels of the protein beta amyloid, which can clump in the brain and form plaques, the other Alzheimer’s lesion.

Encouraging results from animal studies have led researchers to undertake clinical trial with DHA. A nationwide trial will be conducted by the Alzheimer’s Disease Cooperative Study (ADCS), a consortium of leading researchers supported by National Institute on Aging and coordinated by the University of California, San Diego. The trial will take place at 51 sites across the US and seeks 400 participants over the age of 50 with mild to moderate Alzheimer’s disease. Researcher will primarily evaluate whether DHA, taken over months, slows the progression of both cognitive and functional decline in people with mild to moderate Alzheimer’s.