Nervonic acid is a very long-chain monounsaturated omega-9 fatty acid found abundantly in the white matter of the brain and peripheral nervous tissue. It plays a significant role in the maintenance and function of the central nervous system.
The Biological Function of Nervonic Acid
Nervonic acid is a component of myelin, the protective sheath that encases nerve fibers. Myelin, largely composed of lipids, acts like insulation around an electrical wire. It allows for the rapid and efficient transmission of electrical impulses along nerve pathways.
The incorporation of nervonic acid into sphingolipids, a class of complex lipids, contributes to the fluidity and stability of the myelin membrane. A healthy myelin membrane is necessary for nerve signal transduction and proper cell recognition. Without adequate nervonic acid, the myelin sheath’s structure and function can be compromised, affecting nerve communication.
Beyond its role in myelin, nervonic acid also influences the fluidity of neuronal membranes. This fluidity is important for neural signaling and synaptic plasticity, which refers to the ability of brain connections to strengthen or weaken over time. These properties support efficient nerve function.
Natural Sources and Biosynthesis
Nervonic acid can be obtained through dietary sources, though its presence varies. It is found in certain fish oils, such as those derived from sharks, and in some fish like salmon and mackerel. Plant-based sources include oils from the seeds of various plants, such as rapeseed oil, mustard seed oil, and flaxseed oil.
The human body also produces nervonic acid through biosynthesis. This involves the elongation of oleic acid. Through enzymatic steps, two-carbon units are added to oleic acid, with erucic acid (22:1 n-9) serving as an immediate precursor before nervonic acid (24:1 n-9) is formed.
While the body can synthesize nervonic acid, production can sometimes be limited. The efficiency of this biosynthesis pathway may vary among individuals and can decline with age. Dietary intake can therefore play a supportive role in maintaining adequate levels.
Nervonic Acid and Neurological Conditions
Research indicates a connection between abnormal levels of nervonic acid and certain demyelinating neurological conditions. In conditions where the myelin sheath is damaged, such as Multiple Sclerosis (MS) and Adrenoleukodystrophy (ALD), reduced levels of nervonic acid have been observed in brain sphingolipids. This suggests that impaired nervonic acid availability might contribute to disease progression.
In Adrenoleukodystrophy (ALD), an inherited peroxisomal disorder, there is an accumulation of very long-chain saturated fatty acids due to a genetic defect. Studies using ALD patient-derived cells have shown that nervonic acid can help reduce this accumulation, similar to erucic acid used in Lorenzo’s oil. It can also support cellular energy production and reduce oxidative stress in these cells, factors in disease progression.
For Multiple Sclerosis (MS), a disease characterized by myelin loss and inflammation in the central nervous system, research explores whether nervonic acid could support myelin repair or maintenance. Animal studies indicate that nervonic acid treatment can lessen demyelination and inflammation. This approach aims to promote the regeneration of lost myelin and improve nerve function.
Supplementation and Safety Considerations
Nervonic acid supplements are available, often in capsule or oil forms, and are sometimes combined with other compounds like palmitoylethanolamide (PEA) or mushroom extracts. These supplements are marketed for brain health and cognitive support. They aim to provide a direct source of this fatty acid, especially when dietary intake or endogenous production might be insufficient.
A consideration with nervonic acid supplements, particularly those derived from plant sources, is the potential for co-occurrence or contamination with erucic acid. Erucic acid is a related fatty acid that, in high doses, has been associated with adverse effects on heart health in animal studies, though human data on cardiotoxicity are less conclusive. Consumers are advised to seek purified sources of nervonic acid to minimize this exposure.
There is currently no standardized recommended daily intake for nervonic acid. Doses in supplements can vary, with some suggesting a daily range from 30 to 200 mg. Given the complexities of fatty acid metabolism and individual health conditions, consulting a healthcare professional is advisable before initiating any new supplement regimen.