sfa 20:0

Arachidic acid (commonly denoted SFA 20:0) is a very‑long‑chain saturated fatty acid with a 20‑carbon backbone. Chemically known as eicosanoic acid, it is a straight‑chain saturated lipid found in a variety of plant and animal fats. Its name derives from "Arachis," the genus of peanut, where it was originally noted as a minor component. Like other saturated fatty acids, it consists of a carboxyl group and a hydrocarbon chain, but with a longer chain than more common saturated fats such as palmitic (16:0) or stearic acid (18:0). In foods, arachidic acid is present in small amounts relative to other fats, typically appearing in nuts, seeds, and vegetable oils such as macadamia nuts, peanut oil, and soybean oil. Free arachidic acid is usually esterified within triglycerides that make up dietary fats. Physiologically, it can be synthesized in the body through elongation of shorter saturated fatty acids or hydrogenation of unsaturated fatty acids. Unlike essential fatty acids such as linoleic acid or alpha‑linolenic acid, arachidic acid is not considered essential because the body can produce it from other fatty acids. There is no specific Recommended Dietary Allowance for arachidic acid itself. Instead, it contributes to the total pool of saturated fatty acids in the diet, which public health guidance recommends limiting to reduce risk of cardiovascular disease. In clinical settings, measurement of circulating arachidic acid levels (e.g., in plasma phospholipids) may be used as a biomarker of dietary fat intake or metabolic states rather than as a marker of deficiency or requirement.

Arachidic acid has historically been studied largely as a component of dietary fats rather than as a nutrient with specific health benefits. As a saturated fatty acid, it contributes to the structural integrity of cellular membranes and participates in lipid metabolism. Saturated fats, including arachidic acid, are incorporated into chylomicrons after digestion and transported to tissues for storage or energy use. Very‑long‑chain saturated fatty acids such as arachidic acid may also be involved in unique metabolic pathways distinct from shorter saturated fats. Observational research suggests that circulating levels of very‑long‑chain saturated fatty acids (including arachidic acid) are associated with health outcomes. For example, a large cohort study of older adults reported that higher plasma levels of arachidic acid and related very‑long‑chain saturated fatty acids were associated with a lower risk of unhealthy aging events, including cardiovascular disease, physical dysfunction, and cognitive decline. This indicates these fatty acids may serve as integrated biomarkers of diet and metabolism rather than direct effectors of health. However, higher saturated fat intake overall is generally associated with elevated LDL cholesterol levels and cardiovascular risk in controlled feeding studies. Public health guidelines recommend limiting saturated fat intake and replacing it with unsaturated fats to reduce risk of cardiovascular disease. The distinction between different saturated fatty acids is an active area of research, but current evidence does not support specific health claims for arachidic acid intake beyond its role in contributing to overall dietary fat. Because of its structural role in lipids, arachidic acid also may influence membrane fluidity and signaling, although these functions are less well characterized compared with essential polyunsaturated fatty acids.

There are no specific dietary intake recommendations or RDAs established for arachidic acid itself. Health authorities such as the U.S. Dietary Guidelines and World Health Organization provide guidance on saturated fat intake collectively, recommending that total saturated fats make up less than 10% of total caloric intake to reduce cardiovascular disease risk. Arachidic acid comprises a small fraction of total dietary saturated fats, and its intake varies based on consumption of nuts, seeds, and oils. Rather than focusing on a specific amount of arachidic acid, dietary guidance emphasizes overall fat quality. Saturated fats are best replaced with polyunsaturated and monounsaturated fats for cardiometabolic health. Because arachidic acid is not essential, deficiency is not recognized, and there is no recommended intake. However, it contributes to broader dietary patterns and can be quantified in dietary assessments as part of total saturated fats.

Unlike essential nutrients such as vitamins or essential fatty acids (e.g., linoleic acid), arachidic acid has no known deficiency syndrome. The body can synthesize it from other fatty acids, and deficiency has not been described in clinical or population studies. Therefore, there are no specific symptoms that clinicians associate with inadequate intake of arachidic acid specifically. If dietary fats are restricted excessively, individuals may exhibit generalized signs of energy deficiency or poor fat‑soluble vitamin absorption, but these are not attributable to arachidic acid alone. Assessment of plasma very‑long‑chain saturated fatty acids can be done in research settings, but there are no clinical reference ranges used diagnostically. In routine nutrition assessment, plasma fatty acid profiles may show variations based on dietary patterns rather than deficiency states.

Arachidic acid appears in a variety of foods that contain fats, particularly in nuts, seeds, and oils. The richest sources include macadamia nuts and nut oils, peanut oil, and canola oil. Other vegetable oils such as olive oil and soybean oil contain measurable amounts of arachidic acid. Foods containing mixed fats, like dark chocolate or seed mixtures, also supply small quantities. Animal fats and processed foods with added fats may contain arachidic acid in minor amounts. Nuts and seeds such as sesame seeds, hemp seeds, and cashew nuts contribute both healthy unsaturated fats and arachidic acid. Because it is a minor constituent of total fat in most foods, overall intake of arachidic acid tracks with total fat consumption. Including a variety of plant‑based oils and nuts in the diet can increase arachidic acid proportionally within overall fat intake. Culinary fats such as peanut butter and canola oil are practical sources in everyday diets.

Like other dietary fats, arachidic acid is absorbed in the small intestine after emulsification by bile acids and digestion by pancreatic lipases. It is taken up into enterocytes and incorporated into chylomicrons for transport through the lymphatic system to the bloodstream. Once in circulation, it is distributed to tissues where it can be incorporated into triglycerides or phospholipids for structural or energy storage roles. Absorption efficiency for long‑chain saturated fatty acids like arachidic acid is similar to other long‑chain fatty acids and can be influenced by overall fat content of the meal and bile acid secretion.

Supplements of isolated arachidic acid are not marketed for general health, and there is no clinical indication for supplementing this fatty acid. Because arachidic acid is not essential, supplementation does not confer specific benefits beyond contributing to total saturated fat. Individuals focused on health outcomes typically aim to reduce excessive saturated fat intake rather than increase it. If specific therapeutic approaches involving fatty acid modulation are considered, they are under clinical research settings rather than general supplement guidance.

There is no specific Tolerable Upper Intake Level for arachidic acid itself. However, high intake of saturated fats collectively has been associated with elevated LDL cholesterol and increased risk of coronary heart disease. Public health recommendations limit saturated fat intake to reduce such risks. Excessive total saturated fat intake beyond recommended limits contributes to adverse cardiometabolic profiles.

There are no specific drug interactions identified for arachidic acid itself. However, dietary saturated fat intake can influence lipid‑lowering medications such as statins indirectly by affecting lipid profiles. High saturated fat intake may attenuate the lipid‑lowering effects of medications aimed at reducing LDL cholesterol.