Amino Acids Disturbed in Autism? Very Likely

Amino acids in your body are the building blocks for making proteins. There are essential Amino Acids that you must obtain from diet and semi-essential amino acids that in young children are body is still not able to produce and non-essential amino acids that your body can produce. 

There was an earlier post on Amino Acids:- Amino Acids in Autism 

There are also sub-groups, Branch Chained Amino Acids (BCAAs) and aromatic.  The branched chained amino acids (BCAAs) compete with the aromatic amino acids for entry into the brain. Therefore, altering BCAA levels can affect the levels of the neurotransmitters serotonin, dopamine, epinephrine and norepinephrine in the brain. 

Alanine
Arginine (essential)
Asparagine
Aspartic acid
Cysteine
Glutamic acid
Glutamine
Glycine
Histidine (essential) Aromatic
Isoleucine (essential) BCAA
Leucine (essential) BCAA
Lysine (essential)
Methionine (essential)
Phenylalanine (essential)  Aromatic
Proline
Serine
Threonine (essential)
Tryptophan (essential) Aromatic
Tyrosine  Aromatic
Valine (essential)  BCAA 

Taurine is not an amino acid, but often gets treated as if it was one.

Arginine and its derivatives appear to play a critical role in some types of cognitive impairment including Alzheimer's and other forms of dementia.

I am writing new posts about certain individual amino acids that look interesting. Aspartic acid is next and the post looks like getting rather complex, so I decided to highlight an interesting very simplistic study that I stumbled across, that would otherwise get lost in other complex papers.  

I call it simplistic because it compares a control (NT) group with two groups of children with autism, one group has no intervention and the other group is made up of kids with some intervention, of any kind, under the umbrella of digestive/dietary/enzyme/antifungal. The control group was siblings of the children with autism. So three groups in total.

Nonetheless, this Disney science does show something quite surprising. In most cases it looks like any intervention produced results much closer to the reference range than no intervention. The study did not measure whether the intervention had any effect on the severity of autism, or compare the different interventions.

Since I am currently researching Aspartic acid I was drawn to the fact that Aspartic acid was nearly three times higher for the female controls compared with the males.  This I find notable, given the sex difference in autism, which is the biggest clue nature has left us. 

Altered amino acid excretion in children with autism 

A total of 63 subjects were recruited, consisting of 34 autistic children with 31 males and three females aged 5–15 years (mean ± SD, 6.9 ± 2.5 years), and 29 controls with 13 males and 16 females also covering a range of 5–15 years (mean ± SD, 8.9 ± 3.3 years). The controls were derived primarily from siblings of the autistic group, where the sex ratio was more reflective of the general population compared to the sex balance of the autistic population which is recognised as approximately 4:1 (male:female).15 Measures were taken to account for the uneven sex-distribution in the interpretation of the results.

Twenty-two of the autistic children were receiving therapeutic treatments related to digestive function and nutritional uptake. These treatments included antifungal medication, to treat confirmed or suspected Candida infection of the digestive tract, probiotics for maintenance of gut microflora, dietary intervention (gluten- and/or casein-free diet), nutritional supplements, or the hormone secretin; this has been shown to be responsible for regulating pH of the duodenum and is, therefore, pertinent to the functioning of digestive enzymes. On this basis, the autism group was further subdivided into two groups for evaluation of urinary metabolites: treated autistic patients (n = 22; range, 5–15 years; mean, 6.9 ± 2.4 years; 91% male) and untreated autistic patients (n = 12; range, 5–12 years; mean, 7.0 ± 2.5 years; 91% male). To account for any sex-associated differences in urinary output, resulting from the disparity in the sex matching of the autistic and control groups, the control population was first subdivided on the basis of gender.

Two compounds emerged as significantly different on a gender basis for the control group: (i) glucose excretion was of a significantly higher mean concentration for the female control group compared with the males (P <0.05); and (ii) aspartic acid was nearly three times higher for the female controls compared with the males (P < 0.05). No other urinary metabolite concentrations proved to be significantly different between the female and male controls. On this basis, the data from the entire control group were compared with the treated and untreated autistic cohorts.

Plasma amino acids vs urinary amino acids 

There are numerous other studies and they do tend to use a blood test rather than a urine sample. Below is a relatively recent study from Egypt. 

Study of plasma amino acid levels in children with autism: An Egyptian sample

Methods

Twenty autistic children were compared to twenty healthy age and sex matched normal children serving as control, where serum amino acids, urea, ammonia and protein electrophoresis were estimated.

Results

As regards essential amino acid levels, autistic children had significant lower plasma levels of leucine, isoleucine, phenylalanine, methionine and cystine than controls (P < 0.05),while there was no statistical difference in the level of tryptophan, valine, threonine, arginine, lysine and histidine (P > 0.05). In non-essential amino acid levels, phosphoserine was significantly raised in autistic children than in controls (P < 0.05). Autistic children had lower level of hydroxyproline, serine and tyrosine than controls (P < 0.05). On the other hand there was no significant difference in levels of taurin, asparagine, alanine, citrulline, GABA, glycine, glutamic acid, and ornithine (P > 0.05).

There was no significant difference between cases and controls as regards the levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma) (P > 0.05).

Conclusions

Autistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma). 

In conclusion, autistic children may have dysregulated amino acids metabolism as all amino acids except for glutamic acid, phosphoserine and glycine are decreased in patients than in control; the raised glutamic acid may suggest involvement of an altered glutamate transporter and is consistent with a biochemical basis for autistic disorders. Also, the lower amounts of essential amino acids are correlated with more severe autism.

Conclusion

The fair conclusion is that both excreted and plasma amino acids look to be disturbed in autism. Does this tell you anything actionable? Should you become obsessed by trying to reach the reference ranges?

The answer depends on who you ask and I guess who is paying.

The derivatives of some amino acids may indeed be disturbed as a protective mechanism in which the body is adapting to specific effects of that person's autism. This was suggested in the research as one explanation of why agmatine, a derivative of arginine, is elevated in schizophrenia.  In other words elevated agmatine is a good thing in that person, it may well be a biomarker for schizophrenia, but possibly a "good" biomarker. 

If normalizing amino acids does improve autism, then expect the CM-AT treatment from Curemark to pass its phase 3 trials and become an FDA approved therapy for autism. Interestingly when I looked into the Curemark patents a long time ago, secretin appeared and it made another appearance earlier in this post. Secretin is now viewed as a false hope for autism treatment and those who still use it are seen as quacks. In trials secretin was shown not to help most people with autism, but regular readers will know that this is different from saying nobody responds. 

Irrespective of what finally happens to CM-AT, it looks like individual amino acids do have a place in some personalized autism therapies. This may, in some cases, be irrespective of the reference ranges, in other words in some cases an abnormally high level of one amino acid may be required to get a specific beneficial therapeutic effect.  Staying within the reference range is clearly the safer option.

Now I am back to my complicated post about Aspartate and N-acetylaspartate (NAA), which does look very relevant to autism.