GLA (borage) — The Anti-Inflammatory Omega-6
Gamma-linolenic acid (GLA) is a unique omega-6 fatty acid found abundantly in borage seed oil that exerts potent anti-inflammatory effects. By serving as a precursor to anti-inflammatory prostaglandins, GLA helps mitigate chronic, low-grade inflammation, a central hallmark of biological aging known as inflammaging.
Mechanism of Action
Gamma-linolenic acid (GLA) is an omega-6 polyunsaturated fatty acid that bypasses the rate-limiting enzyme delta-6-desaturase. Once consumed, GLA is rapidly elongated to dihomo-gamma-linolenic acid (DGLA). DGLA competes with arachidonic acid for cyclooxygenase (COX) and lipoxygenase (LOX) enzymes, shifting the eicosanoid balance away from pro-inflammatory mediators (like PGE2 and LTB4) toward anti-inflammatory prostaglandins (PGE1) and 15-HETrE. This mechanism dampens systemic inflammation, which is a key driver of inflammaging and age-related chronic diseases.
Human Trial Evidence
Multiple randomised controlled trials have investigated GLA for rheumatoid arthritis, showing modest but significant reductions in joint tenderness and swelling at high doses (1.4–2.8 g/day). Trials in atopic dermatitis (eczema) have yielded mixed results, with some showing benefit and others, including a large well-controlled trial, showing no significant improvement over placebo. There are no published human longevity trials.
Dosing Protocol
1.4–2.8 g/day of GLA (typically requiring 6–12 g of borage oil) is the most studied range in human trials for rheumatoid arthritis. It is typically taken in divided doses with meals. Lower doses (300–500 mg/day of GLA) are sometimes used for mild skin conditions, though efficacy is mixed.
Safety & Contraindications
Generally well tolerated. Mild gastrointestinal side effects such as soft stools, belching, and bloating can occur. Borage oil may contain trace amounts of pyrrolizidine alkaloids (PAs) which are hepatotoxic; therefore, only PA-free certified borage oil should be used. It may increase bleeding risk, so caution is advised in patients taking anticoagulants or antiplatelet drugs.