When it comes to Arachidonic Acid (ARA), the first thing many people think of is the nutritional content in infant formula. However, ARA is not just an “exclusive nutrient” for infants and young children—it also plays an important role in the health of adults that cannot be ignored. This article will systematically introduce the many benefits, food sources and precautions of ARA to adult health, and help you scientifically understand this important omega-6 polyunsaturated fatty acid.
What is ARA?
ARA, the full name of arachidonic acid, is a twenty-carbon unsaturated fatty acid containing four carbon-carbon double bonds. The chemical formula is C₂₀H₃₂O₂, and it is an omega-6 polyunsaturated fatty acid. It is the most abundant and widely distributed polyunsaturated fatty acid in human tissues and is widely present in the cell membranes of all tissues in the form of phospholipids.
ARA can be biosynthesized in the human body from linoleic acid through desaturation and carbon chain elongation, or it can be ingested directly from food. Since the synthetic capacity of adults can generally meet basic needs, ARA is considered a "semi-essential fatty acid". It is not only an important component of the cell membrane, giving it the necessary fluidity and flexibility, but it is also the precursor of a variety of biologically active substances (such as prostaglandins, leukotrienes, etc.) and participates in regulating many physiological functions of the human body.
The main health effects of ARA on adults
1. Maintain brain function and cognitive abilities
ARA is abundant in the brain and nervous system and is an important structural component of nerve cell membranes. Research shows that ARA plays an important role in maintaining normal cognitive function, memory ability and learning ability. ARA deficiency may lead to intellectual dysfunction in adolescents and premature neurological degeneration in the elderly.
As we age, there is a natural decline in brain function. Research indicates that ARA and DHA supplementation may help prevent and improve age-related decline in brain function. In addition, epidemiological studies and Mendelian randomization analysis have shown that higher levels of ARA intake are significantly associated with lower incidence of schizophrenia, and ARA may be a potential protective factor against schizophrenia.
ARA's metabolite, endocannabinoids, also plays a key role in brain reward signaling, motivational processes, mood, stress response, pain and energy balance.
2. Promote muscle repair and growth
For adults concerned about fitness and athletic performance, ARA is a nutrient worth paying attention to. Muscle tissue is the primary storage site for ARA. Multiple human experimental studies have found that dietary supplementation of ARA can significantly increase ARA levels in plasma and muscle, and promote the expression of myogenic regulatory factors, which are closely related to the repair and growth of skeletal muscle.
A randomized controlled trial showed that men who supplemented with 1.5 grams of ARA daily during an 8-week resistance training program experienced significantly greater gains in muscle mass and strength than those in the placebo group. Another study found that the ARA-supplemented group experienced a significant increase in lean body mass of 1.6 kg (about 3%), while the placebo group showed little change. These studies suggest that ARA has potential value in supporting muscle health in adults.
3. Support cardiovascular health
The role of ARA in the cardiovascular system also deserves attention. ARA has physiological activities that esterify cholesterol, increase blood vessel elasticity, and reduce blood viscosity. Studies have confirmed that arachidonic acid can significantly reduce blood sugar, blood lipids and blood cholesterol, while reducing low-density lipoprotein cholesterol (LDL-C) and very low-density lipoprotein cholesterol (VLDL-C), and increasing high-density lipoprotein cholesterol (HDL-C).
ARA can also reduce thrombosis, prevent coronary heart disease, and has positive significance in maintaining vascular health. For people with higher blood viscosity, dietary supplementation with ARA can help improve blood rheology indicators.
4. Regulate immune system function
ARA plays an important role in the normal functioning of the immune system. Free ARA and its metabolites can promote and regulate type 2 immune responses, which are crucial for resisting parasites and allergens.
The latest research in 2025 revealed that dietary supplementation of ARA can significantly enhance the humoral immune response induced by vaccines and help the body quickly produce high levels of neutralizing antibodies, thus providing earlier and stronger immune protection. The mechanism is that ARA is enriched in lymph nodes and metabolized into active substances, among which prostaglandin I₂ (PGI₂) is identified as the key molecule.
It is important to point out that although ARA is a precursor of inflammation-related eicosanoids, multiple human studies have found that increasing ARA intake does not significantly increase the levels of inflammatory markers in the body. On the contrary, mediators such as lipoxins produced by ARA metabolism play an important role in inflammation resolution and tissue healing. The study found that the mononuclear leukocyte count in the blood and the mRNA expression of peripheral blood mononuclear cells even decreased slightly after ARA supplementation, suggesting that the basic systemic inflammatory response was weakened.
5. Maintain vision and retinal health
ARA is an important component of the retina and plays an important role in maintaining normal visual function. Sufficient ARA helps protect the retina and improve vision. Although the role of ARA in the visual development of infants and young children is better known, adults also need ARA to maintain the normal function of the visual system.
Food sources and intake recommendations for ARA
main food sources
Healthy adults can meet their ARA needs through their daily diet. Major food sources of ARA include:
Animal foods: beef, chicken, eggs, fish, etc.
Animal offal: The heart, liver, kidney and other parts of animals are particularly rich in content
Vegetable oil: soybean oil, walnut oil, etc.
Nuts: walnuts, etc.
Some plants: some mosses, seaweeds, etc. also contain small amounts of ARA
Intake recommendations
Daily dietary intake of ARA for healthy adults typically ranges from 100-250 mg/day. For generally healthy adults, normal diet can meet ARA needs, and no additional supplementation is generally required.
If considering taking an ARA supplement, it is recommended that daily intake be limited to 600 mg. Studies have shown that adults increased ARA intake from the daily 100-200 mg/day to 1000 mg/day, or even 1500-2000 mg/day, and no obvious adverse effects were observed. However, the safety of long-term high-dose supplementation still needs more research to confirm.
Precautions for special populations
Elderly people or people with specific diseases: If you need to supplement ARA, you should do so under the professional guidance of a doctor or nutritionist.
Vegetarians: Since ARA is almost absent in plant foods, vegans may need to pay special attention to their ARA intake.
Cancer patients: Existing research suggests that dietary ARA supplementation in cancer patients may help increase muscle and plasma ARA levels and improve blood viscosity.
The relationship between ARA and DHA
ARA (ω-6) and DHA (ω-3) are the two most important long-chain polyunsaturated fatty acids in the human body. The two play complementary but different physiological functions in the human body. DHA has a unique role in anti-allergic reactions, such as reducing the incidence of bronchial asthma, allergic dermatitis and other diseases. ARA plays an irreplaceable role in brain development, muscle repair and immune regulation.
Adults also need DHA and ARA to maintain normal brain and body functions. When purchasing products containing ARA and DHA, you should pay attention to their content and ratio. my country's national standards require that if DHA is added to the product, the ARA content should be no less than DHA.
Safety and precautions
ARA has low toxicity, and the acute oral lethal dose (LD50) in animal experiments was greater than 2000 mg/kg. However, consumers still need to pay attention to the following points:
No need to blindly supplement: Healthy adults can meet their ARA needs through daily diet, and generally do not need additional supplements
Be wary of product contamination: ARA raw materials may introduce Bacillus cereus toxins due to microbial contamination during the production and storage process. Eating contaminated products may cause diarrhea, vomiting and other digestive problems.
Choose regular products: When purchasing products containing ARA, you should choose regular brands and pay attention to product identification and raw material traceability information.
Viewed rationally: The milk powder recall incident was caused by contamination of ARA raw materials, not ARA itself. There is no safety problem. Consumers need not panic too much.
Conclusion
As one of the most important omega-6 polyunsaturated fatty acids in the human body, ARA plays an important role in adult brain function, muscle health, cardiovascular health, immune regulation and vision maintenance. For most healthy adults, a balanced daily diet (including appropriate amounts of meat, eggs, etc.) can provide sufficient ARA. If special groups of people need additional supplementation, they should do so under the guidance of professionals. Only by scientifically understanding ARA and consuming it properly can this important nutrient better serve our health.
