Stearidonic acid (SDA) is an octadecatetraenoic acid and long-chain fatty acid with four cis double bonds at positions 6, 9, 12, and 15. This polyunsaturated fatty acid is found in Cladosiphon okamuranus, Mucor javanicus, Lithospermum officinale, fatty fish, seed oils, and fish oil. SDA is present in various oils as a percentage of total fatty acids. It has a role as a plant metabolite, a Daphnia galeata metabolite, and a mouse metabolite. It is an omega-3 fatty acid that is formed upon the desaturation of alpha linolenic acid and is a precursor of eicosapentaenoic acid and docosahexaenoic acid. SDA is an anti-inflammatory metabolite, with known benefits in diverse cardiovascular, inflammatory, and neurological disorders1.

Stearidonic acid and cardiovascular disease

SDA may be beneficial for individuals with elevated blood lipid levels. For example, individuals with slightly high triglycerides showed reduced levels after SDA supplementation via echium oil. In addition, SDA treatment lowered patient omega-3 indices, which measure the amount of EPA and DHA in the membrane of red blood cells and is a biomarker of cardiovascular disease. SDA is known to increase red blood cell EPA content, highlighting its potential cardiovascular benefits. In obese patients, SDA treatment may reduce low-density lipoprotein levels, but does not affect high-density lipoprotein or total cholesterol levels. Although SDA treatment is beneficial in these select cases, it remains unclear whether the metabolite has an impact on blood lipids in healthy individuals. Further investigation on how SDA affects cellular lipid absorption and degradation could provide useful insights2-4.

Stearidonic acid and inflammatory diseases

Many omega-3 fatty acids, including SDA, have been shown to possess anti-inflammatory properties. SDA specifically may reduce inflammation during rheumatoid arthritis. In a mouse model, animals fed low doses of SDA displayed reduced inflammation scores. Mechanistically, SDA may act to reduce inflammation caused by inflammatory macrophages. When treated with SDA, macrophages stimulated with lipopolysaccharide showed downregulation of the inducible nitric oxide synthase, a protein responsible for producing nitric oxide and other inflammatory reactive oxygen species. Furthermore, SDA also reduced the activation of inflammatory macrophages by inhibiting nuclear translocation of the transcription factor NFκB and phosphorylation of mitogen-activated protein kinases. These results indicate that SDA has anti-inflammatory properties and acts via diverse mechanisms. However, additional animal and human studies are needed to determine if SDA could be a viable supplement to existing treatments for rheumatoid arthritis and other inflammatory conditions5,6.

Stearidonic acid and skin health

SDA provides significant benefits to skin primarily due to its anti-inflammatory and barrier-enhancing properties. For example, by modulating the inflammatory response, SDA treatment partially alleviates conditions including atopic dermatitis and eczema. Clinical studies have also shown that dietary and topical applications of SDA via hemp seed oil can reduce symptoms of dry and inflamed skin. SDA improves the function of the skin barrier by incorporating into cell membranes, which enhances their fluidity and helps the skin retain moisture and protect against irritants. These results indicate that SDA consumption and topical application may be viable treatment options for atopic dermatitis, eczema, and other inflammatory skin disorders. However, more research is needed in humans to determine the benefits and risks of long-term topical SDA treatments7-9.

Stearidonic acid and neurological disorders

SDA may also play a protective role in neurological disorders such as Alzheimer’s disease and stroke through its anti-inflammatory properties. One recent study showed that SDA is enriched in the serum of stroke survivors. Furthermore, rat hippocampal neurons treated with SDA resisted apoptosis when exposed to amyloid beta, the pathological component of Alzheimer’s disease. In addition, SDA improved neuronal antioxidant capacity, reduced expression of proinflammatory mediators, and activated pro-survival signaling pathways. These results suggest that high dietary intake of polyunsaturated fatty acids, such as SDA, may reduce neuronal cytotoxicity, neuronal loss, and the risk of developing Alzheimer’s disease. However, additional studies in animal models and humans are needed to determine the prophylactic effects of SDA on neurological symptoms10,11.

Stearidonic acid in research

As of July 2024, there are only 59 citations for stearidonic acid in research publications (excluding books and documents) on Pubmed. Thus, more research, both in vitro and in vivo, on SDA’s fundamental and therapeutic qualities is needed. However, preliminary evidence suggests that SDA may be beneficial to human health and for treating inflammatory conditions such as atopic dermatitis, eczema, and rheumatoid arthritis as well as neurological conditions such as Alzheimer’s disease.

References

  1. National Library of Medicine, National Center for Biotechnology Information. PubChem Compound Summary, Stearidonic acid (CID 5312508). https://pubchem.ncbi.nlm.nih.gov/compound/Stearidonic-acid
  2. Lemke SL, Vicini JL, Su H, et al. Dietary intake of stearidonic acid-enriched soybean oil increases the omega-3 index: randomized, double-blind clinical study of efficacy and safety. Am J Clin Nutr. 2010;92(4):766-775. doi:10.3945/AJCN.2009.29072
  3. Harris WS. The omega-3 index as a risk factor for coronary heart disease. Am J Clin Nutr. 2008;87(6). doi:10.1093/AJCN/87.6.1997S
  4. Surette ME, Edens M, Chilton FH, et al. Dietary echium oil increases plasma and neutrophil long-chain (n-3) fatty acids and lowers serum triacylglycerols in hypertriglyceridemic humans. J Nutr. 2004;134(6):1406-1411. doi:10.1093/JN/134.6.1406
  5. Sung J, Jeon H, Kim IH, et al. Anti-Inflammatory Effects of Stearidonic Acid Mediated by Suppression of NF-κB and MAP-Kinase Pathways in Macrophages. Lipids. 2017;52(9):781-787. doi:10.1007/S11745-017-4278-6
  6. Leventhal LJ, Boyce EG, Zurier RB. Treatment of rheumatoid arthritis with blackcurrant seed oil. Br J Rheumatol. 1994;33(9):847-852. doi:10.1093/RHEUMATOLOGY/33.9.847
  7. Callaway J, Schwab U, Harvima I, et al. Efficacy of dietary hempseed oil in patients with atopic dermatitis. J Dermatolog Treat. 2005;16(2):87-94. doi:10.1080/09546630510035832
  8. Ziboh VA, Miller CC, Cho Y. Metabolism of polyunsaturated fatty acids by skin epidermal enzymes: generation of antiinflammatory and antiproliferative metabolites. Am J Clin Nutr. 2000;71(1 Suppl). doi:10.1093/AJCN/71.1.361S
  9. Horrobin DF. Essential fatty acid metabolism and its modification in atopic eczema. Am J Clin Nutr. 2000;71(1 Suppl). doi:10.1093/AJCN/71.1.367S
  10. Li Y, Lai W, Zheng C, et al. Neuroprotective Effect of Stearidonic Acid on Amyloid β-Induced Neurotoxicity in Rat Hippocampal Cells. Antioxidants (Basel). 2022;11(12). doi:10.3390/ANTIOX11122357
  11. Kotlęga D, Peda B, Palma J, et al. Free Fatty Acids Are Associated with the Cognitive Functions in Stroke Survivors. Int J Environ Res Public Health. 2021;18(12). doi:10.3390/IJERPH18126500