Nutritional Treatments of Autism - Fatty Acids

FATTY ACIDS

Background

We have, for a long time, been told that fats are bad for us. Whilst many fats are, some are not, and these good fats are essential to the effective functioning of the brain (Richardson, 2003). Unfortunately, because these fats are often easily destroyed by light and heat, they are removed from food in order to increase its shelf life. There are four types of fats that our bodies process from food, these are cholesterol, saturated fat, monounsaturated fat and polyunsaturated fats. The polyunsaturated fats include the essential fatty acids. Some fatty acids cannot be made by the body from the other fats it absorbs, therefore they are termed essential fatty acids.

There are two groups of essential fatty acids, the omega-3s and the omega-6s. There are a range of fats in each of these groups, many of which can be made from other fats in the same group by most people. However, to ensure adequate intake, supplements should contain the whole range. The balance between the omega-3s and the omega-6s is very important and in the modern day diet the proportions are out of balance (Simopoulos, 2002). Therefore it is important to have more omega-3s in order to stabilise the ratios.

Essential fatty acids (EFAs) are essential for immunity, production of hormones, good digestion and absorption, nerve cell function and learning. Research has shown that daily usage of cod liver oil has led to improved eye contact and behaviour in children with autism.

Flax seed oil supplies alpha linoleic acid (ALA) which is deficient in many diets because of food processing and dietary choices. Fish oils also supply docosahexanoic acid (DHA). DHA is the omega-3 EFA with the highest concentration in the brain (DHA in Mind, 2007). If behaviour issues or autistic symptoms intensify with omega-3 supplementation, this might suggest the need for omega-6 supplementation. Inadequate DHA levels result in memory loss and other neurological problems (Richardson, 2002). Research shows DHA levels are often lower in children suffering from autism than normal children. Clinical studies also show that DHA supplementation can improve behaviour in these children.

The leading omega-6 EFA is linoleic acid (Supplement News, 2007). Levels of linoleic acid can be increased by supplementing with evening primrose oil or borage oil, which supply the biologically active linoleic derivative, gamma linoleic acid (GLA). Proper EFA supplementation might not only improve behaviour but also dryness of the skin and hair and brittle nails.

Arachidonic acid is an omega-6 fatty acid which is abundant in the brain (Bryhn, 2005). Like DHA, arachidonic acid is an important structural component of cell membranes in the eye and brain where it helps facilitate healthy communication between nerve cells, deficiency in this seems to be a factor in hyperactivity.

Research indicates that the addition of fatty acids to the diet has shown dramatic improvement in reading, learning ability, hand writing and concentration. This improvement leads to an increase in confidence and social skills. Research on 230 inmates at a Buckinghamshire young offenders institution (Gesch, 2002) showed that the number of offences committed by prisoners who were on dietary supplements dropped by a quarter compared to those who were on dummy tablets.

Evaluation

The research on fatty acids and autism began fairly recently, in 1999, when Kane (1999) detailed a range of biological findings and hypotheses about autistic spectrum disorders including suggestions about fatty acid metabolism. This was followed by Bell et al (2000) who measured the fatty acids in the red blood cells and found very high levels of saturates in those with autism (Table 3). They found that the blood of one of the children with Asperger’s Syndrome had dramatic reductions in the HUFA (highly unsaturated fatty acids) content in the red blood cells when stored at –20^OC compared to the other samples and he theorised that these fatty acids are relatively unstable, which could have many implications on physiology particularly in relation to the nervous system and the synaptic junctions which could then lead to autistic type symptoms and epilepsy. However, his study was only on six people, two with autism, two with Asperger’s Syndrome and two normal controls and no p figures are given along with little information about how he performed these tests.

Next Vancassel et al (2001) did a similar study measuring the phospholipid fatty acids in the blood cells (Table 3). They studied fifteen children with autism and eighteen mentally retarded children. They found a significantly lower level of polyunsaturated fatty acids, particularly the docosahexaenoic acid (DHA) in the blood of those with autism. However, again it was on a small number of children and also the controls were mentally retarded and not typical children. All the children were from the same Child Psychiatry Day Care Unit, which may specify a certain type of child. Also, it was based in Tours, the same place where much of the B6 and magnesium research took place and whilst the children are unlikely to be the same ones, due to the fact that that research took place over 10 years ago, the children may be related and there may be other links.

After this Bell et al (2003) produced a health questionnaire asking questions to see if there were signs of fatty acid deficiency (Table 3). The levels of the different fatty acids in the polar lipids in the red blood cells was also analysed. This was a small scale study and questionnaires can be very unreliable. However, the results from the blood analysis showed significant differences in the fatty acid contents.

Next Patrick and Salik (2005) ran a study on 22 children with autism or Asperger’s syndrome who took an essential fatty acid supplement for 90 days (Table 3). The results showed a significant increase in their language and learning skills. However this study was on a small number of children and, as the authors say, it shows a need for further studies using larger sample sizes and which are placebo controlled. There is also limited information given in the report of this study.

In the same year Richardson and Montgomery (2005) performed a randomised, controlled crossover trial on 117 children with developmental coordination disorder taking omega-3 and omega-6 fatty acids which found significant improvements in reading, spelling and behaviour (Table 3). Since this was done on children with developmental coordination disorder rather than autism it is not strictly relevant, however the two conditions seem to be closely related so it is another indication that further research is necessary. Measurements was were taken on behaviour, reading and spelling by teachers. All showed significant improvement. However no measurements were taken by parents or independent advisors. Also, there was no washout period between the two parts of the study to ensure that the effects of the fatty acids had ceased before taking the placebo (or vice versa).

Rimland and Edelson (2005) in their survey found that over half of those who had tried fatty acids (626 sets of parents) showed some improvement (Table 3). This survey is an ongoing one where parents are asked to say which interventions they have tried and with what success. It is obviously not a very reliable method, but the quantity of parents who have given feedback makes it very interesting.

Later Bu et al (2006) performed further research on the fatty acid composition of blood in children with autism (Table 3). This study was on twenty children with early onset autism, twenty with developmental regression, twenty with non-autistic developmental disabilities and twenty typical controls. These children were all aged between two and five. They found increases in the eicosenoic acid and erucic acid in those children with autism as compared with typical children and those with non-autistic developmental difficulties. There were also other differences in the fatty acid constituents in the blood of those with autism compared to the other children. This again was a small scale study and only on young children.

Summary

The research on using fatty acids with autism is very much in its infancy. There are some indications that it may help but there is still a lot to understand about its effects in the body, what sort of dosage would be required and if there are any side effects. Larger scale studies are underway at the moment so hopefully they will produce some convincing evidence in the near future.