Polyunsaturated fats (PUFAs), particularly omega-3 fatty acids such as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) found in fish oil, have been scientifically studied for their potential role in supporting joint health. A substantial body of research has investigated the anti-inflammatory properties of omega-3 PUFAs, which can modulate the production of inflammatory cytokines and eicosanoids implicated in joint disorders such as rheumatoid arthritis (RA) and osteoarthritis (OA).

Randomized controlled trials and meta-analyses suggest that supplementation with omega-3 PUFAs can lead to modest reductions in joint pain, morning stiffness, and the use of non-steroidal anti-inflammatory drugs (NSAIDs) in patients with RA. The mechanism is believed to involve the suppression of pro-inflammatory mediators and a shift towards anti-inflammatory lipid mediators. However, the evidence for benefits in OA is less consistent, and effects tend to be moderate rather than dramatic.

Non-omega-3 PUFAs (such as omega-6 fatty acids) have not shown the same beneficial effects and may even promote inflammation if consumed in excessive amounts relative to omega-3s. Therefore, the scientific support for PUFAs in joint health specifically pertains to omega-3 fatty acids, and not all polyunsaturated fats in general. While not a cure, omega-3 PUFAs are recognized as a supportive measure for joint health, particularly in inflammatory joint diseases.