Arachidonic acid (AA) is a polyunsaturated omega-6 fatty acid that plays a crucial role in human physiology. Though often overlooked in discussions of nutrition and biochemistry, it is essential for the proper functioning of the brain, muscles, and immune system. Found predominantly in animal-based foods like meat, eggs, and dairy, arachidonic acid is both consumed in the diet and synthesized in small amounts from linoleic acid, another omega-6 fatty acid.
One of the most important functions of arachidonic acid is its role as a precursor to a class of bioactive lipids called eicosanoids, which include prostaglandins, thromboxanes, and leukotrienes. These molecules regulate numerous physiological processes, such as inflammation, blood clotting, and immune responses. While eicosanoids derived from AA can promote inflammation, this is not inherently negative—controlled inflammation is essential for wound healing, immune defense, and muscle repair.
In the brain, arachidonic acid is a major structural component of cell membranes, especially in neurons. It helps maintain fluidity in neural membranes and supports signal transmission, which is vital for cognitive function, memory, and mood regulation. AA is also involved in neurogenesis, or the formation of new neurons, highlighting its importance in early brain development as well as long-term neurological health.
In sports nutrition and bodybuilding, arachidonic acid has gained attention for its role in muscle growth and recovery. When muscles are stressed during resistance training, AA is released and contributes to the localized inflammatory response, triggering a cascade of signals that promote muscle adaptation and growth. Some athletes use AA supplements to enhance strength and muscle mass, though it must be balanced carefully with anti-inflammatory nutrients to avoid excessive inflammation.
The immune system also relies on arachidonic acid. It aids in the activation and regulation of white blood cells, and helps the body respond to infections and injuries. However, imbalances—particularly excessive intake of omega-6 fatty acids without enough omega-3s—can lead to chronic inflammation, which is associated with conditions such as arthritis, cardiovascular disease, and metabolic disorders.
In infant nutrition, arachidonic acid is often included in formula alongside docosahexaenoic acid (DHA), an omega-3 fatty acid. Together, these fats support visual and cognitive development during early childhood, mimicking the nutrient profile of breast milk.
