Folic Acid and Autism: A Systematic Review of the Current State of Knowledge.

Folic acid has been identified to be integral in rapid tissue growth and cell division during fetal development. Different studies indicate folic acid's importance in improving childhood behavioral outcomes and underline its role as a modifiable risk factor for autism spectrum disorders. The aim of this systematic review is to both elucidate the potential role of folic acid in autism spectrum disorders and to investigate the mechanisms involved. Studies have pointed out a potential beneficial effect of prenatal folic acid maternal supplementation (600 µg) on the risk of autism spectrum disorder onset, but opposite results have been reported as well. Folic acid and/or folinic acid supplementation in autism spectrum disorder diagnosed children has led to improvements, both in some neurologic and behavioral symptoms and in the concentration of one-carbon metabolites. Several authors report an increased frequency of serum auto-antibodies against folate receptor alpha (FRAA) in autism spectrum disorder children. Furthermore, methylene tetrahydrofolate reductase (MTHFR) polymorphisms showed a significant influence on ASD risk. More clinical trials, with a clear study design, with larger sample sizes and longer observation periods are necessary to be carried out to better evaluate the potential protective role of folic acid in autism spectrum disorder risk.

The Interaction between Arachidonic Acid Metabolism and Homocysteine.

Hyperhomocysteinemia (HHcy) has been considered a risk factor for different diseases, including cardiovascular disease (CVD), inflammation, neurological diseases, cancer, and many other pathological conditions. Likewise, arachidonic acid (AA) metabolism is implicated in both vascular homeostasis and inflammation, as shown by the development of CVD, following the imbalance of its metabolites. This review summarizes how homocysteine (Hcy) can influence the metabolism of AA. In silico literature searches were performed on PubMed and Scopus as main sources. Several studies have shown that altered levels of Hcy, through AA release and metabolism, can influence the synthesis and the activity of prostaglandins (PGs), prostacyclin (PGI2), thromboxane (TXA), epoxyeicosatrienoic acids (EETs), and hydroxyeicosatetraenoic acids (HETEs). It is believed that by targeting Hcy in the AA pathways, novel compounds with better pharmacological and pharmacodynamics benefits may be obtained and that this information is valuable for a dietician to manipulate diets to improve health.