Detailansicht für den Begriff

Name des Begriffes: Arachidonic acid

Short introduction

  • Arachidonic acid (ARA, C20:4) and docosahexaenoic acid (DHA, C22:6) are long chain polyunsaturated fatty acids (LCPUFAs).
  • ARA can be added to infant formulas (in HOCHDORF infant formulas, this is added as Mortierella alpina oil). ARA can also be synthesised endogenously (produced within body) from the essential fatty acid linoleic acid (LA).

From ALA to DHA and from LA to ARA

  • LA is the parent of the Ω/ω /omega-6 or n-6 family. LA is the precursor (forerunner) of ARA. ALA (α-linolenic acid) is the parent of the Ω/ω/omega-3 or n-3 family and precursor of DHA.
  • LA is converted via α-linolenic acid (gamma-linolenic acid, GLA) with the help of specific enzymes and via various other fatty acids into the LCPUFA arachidonic acid (ARA). ALA is converted via eicosapentaenoic acid (EPA) with the help of specific enzymes and via various other fatty acids into the LCPUFA docosahexaenoic acid (DHA).
  • For the conversion, both families (omega-3 and omega-6) use the same enzymes (e.g. elongase), resulting in competition between the two families. In order to produce the required amount of DHA and ARA, the right balance (good ratio) between ALA and LA is important – e.g. a diet rich in LA reduces ALA conversion. Thus, high-LA levels in the diet generally result in low n-3 LCPUFA status.
  • There is no specific regulation (EU regulation 2016/127) for the ALA/LA ratio. To promote an efficient conversion a low ratio is nutritionally recommended (range: 1:5 – 1:15).

New regulation: DHA now mandatory and ARA optional in IF and FOF

  • Due to insufficient activity of the conversion enzymes, the rate of conversion ALA to DHA and LA to ARA is low – especially in early infancy. DHA and ARA levels depend, to a great extent, on dietary intake.
  • Due to the rapid brain and nerve growth in early infancy, the level of DHA and ARA synthesis may be inadequate to keep up with the demand. Therefore, supplementation of IF and FOF with LCPUFAs is now widely recommended.
  • The recent revision of the European legislation (EU regulation 2016/127) stipulates that all IF and FOF must contain DHA; formulas without DHA content will not be permitted in the European Union once this legislation is implemented.
  • The addition of ARA is optional but is justified from an ethical nutritional point of view in line with the latest scientific insights.

Main natural sources

  • Examples include: meat, poultry, egg yolk, peanut oil.
  • ARA (as well as ALA, LA and DHA) is present in breast milk.

Main function

LCPUFAs (DHA and ARA) play a beneficial role throughout life.

  • For normal growth and development.
  • For the developing brain, during pregnancy and early childhood and for life-long brain health. For cognitive (brain memory and performance) and behavioural development and function.
    • DHA and ARA are important functional and structural components of the brain.
    • The brain consists of approximately 50-60 % fat, around 35 % of which is DHA and ARA.
    • The brain in mammals consists of about 60% fat, which requires DHA and ARA for its growth and function. The two fatty acids account for approximately ~25% of the total fatty acid content, predominately in the form of phospholipids, and are thus major structural components of neural cellular membranes.
    • DHA is a major component (50 %) of the retina (light-sensitive eye layer) and important for visual development.
    • Omega-3 and omega-6 fatty acids are structural components of cell membranes and DHA and ARA, especially, are found in abundance in cell membranes of the brain. DHA and ARA increase flexibility and permeability of the membrane, which provides optimal conditions for a wide range of cell membrane functions. Cell membranes are the ‘communication centres’ of the brain. Nerve cells communicate with each other via membrane processes (e.g. cell signalling) and regulate cell activity. In addition, they allow movement of nutrients into and waste products out of nerve cells.
    • DHA and ARA are vital to the composition of the myelin sheath. Myelin covers the lengthened outgrow of the nerve cell (axon). This ensures fast transmission of information to other nerve cells – without myelin, nerves work slowly and inefficiently.

In cell membranes, LCPUFAs have specific roles that contribute to immune cell responses. Studies show intake of LCPUFAs early in life can influence immune development.

  • Chronic inflammation is the cause of many chronic diseases, including cardiovascular disease. DHA gives rise to compounds involved in anti-inflammation processes. ARA is the precursor of compounds with pro-inflammatory and anti-inflammatory effects but further research is required.
  • Effects include lowering cholesterol and blood pressure (lowering the risk of heart attack, stroke, abnormal heart rhythms). DHA plays a role in prevention and treatment of atherosclerosis (fatty plaques inside artery walls).
  • Both omega-3 and omega-6 fatty acids are beneficial for improving lipid profiles in healthy individuals and are important for cardiovascular health (from childhood onwards).

Although the speed of accumulation subsequently decreases, the incorporation of DHA and ARA in brain remains high up to the age of two.

Deficiency-related disease

  • Risk of cardiovascular diseases (heart attack, stroke) and atherosclerosis.
  • Signs and symptoms of an omega-3/omega-6 deficiency include allergic or atopic tendencies (eczema, asthma, hay fever), visual symptoms (poor night vision, visual disturbances), attention problems (poor concentration, attention and memory problems), emotional sensitivity (depression, excessive mood swings, anxiety), disturbed sleep-wake cycle and decreased immunity (increased susceptibility to diseases and infection, poor wound healing).
  • In infants and children, growth may be decreased. Studies in children show the negative impact on neurocognitive development – associated with impairment in cognitive (brain memory and performance) and behavioural performance.

DRIs (Dietary Reference Intakes) have not been established for arachidonic acid (ARA).

Synonyme: ARA

Zurück zur Liste