Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in oily fish and fish oil supplements. These fatty acids have anti-inflammatory properties, influencing various aspects of inflammation, including leucocyte chemotaxis, adhesion molecule expression, and eicosanoid production. They can reduce the production of inflammatory cytokines and promote the synthesis of anti-inflammatory resolvins and protectins. Mechanisms underlying their anti-inflammatory effects include altering cell membrane phospholipid composition, disrupting lipid rafts, inhibiting nuclear factor kappa B (NFκB) activation, and activating the anti-inflammatory transcription factor PPAR-γ. These mechanisms are interconnected, and high doses of EPA and DHA (greater than 2 g/day) are generally required to elicit significant anti-inflammatory effects. Animal studies show benefits of n-3 PUFAs in conditions like rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and asthma. Clinical trials of fish oil in RA patients show benefits supported by meta-analyses, while trials in IBD and asthma are inconsistent. Inflammation is a normal host defense mechanism that can become excessive or chronic, leading to tissue damage. It involves interactions among various cell types and the production of chemical mediators. n-3 PUFAs can reduce inflammation by altering membrane composition, inhibiting pro-inflammatory signaling, and promoting anti-inflammatory responses. n-3 PUFAs are structural descriptors for a family of PUFAs with a double bond near the methyl terminus. They are synthesized in plants but not in animals. EPA and DHA are found in fish and fish oil, and are involved in various inflammatory processes. They influence eicosanoid production, endocannabinoid levels, and inflammatory cytokine production. They also affect T-cell reactivity and inflammatory signaling pathways, including NFκB and PPAR-γ. The anti-inflammatory effects of n-3 PUFAs are mediated through various mechanisms, including receptor activation (GPR120 and PPAR-γ), inhibition of NFκB activation, and production of resolvins and protectins. These effects are supported by studies in cell cultures, animal models, and clinical trials. However, the required dose for significant anti-inflammatory effects is often higher than typical dietary intakes. While n-3 PUFAs are naturally occurring nutrients, their role in pharmacology is being explored due to their ability to modulate inflammatory responses. The distinction between nutrition and pharmacology depends on the dose required to elicit an anti-inflammatory effect.Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in oily fish and fish oil supplements. These fatty acids have anti-inflammatory properties, influencing various aspects of inflammation, including leucocyte chemotaxis, adhesion molecule expression, and eicosanoid production. They can reduce the production of inflammatory cytokines and promote the synthesis of anti-inflammatory resolvins and protectins. Mechanisms underlying their anti-inflammatory effects include altering cell membrane phospholipid composition, disrupting lipid rafts, inhibiting nuclear factor kappa B (NFκB) activation, and activating the anti-inflammatory transcription factor PPAR-γ. These mechanisms are interconnected, and high doses of EPA and DHA (greater than 2 g/day) are generally required to elicit significant anti-inflammatory effects. Animal studies show benefits of n-3 PUFAs in conditions like rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and asthma. Clinical trials of fish oil in RA patients show benefits supported by meta-analyses, while trials in IBD and asthma are inconsistent. Inflammation is a normal host defense mechanism that can become excessive or chronic, leading to tissue damage. It involves interactions among various cell types and the production of chemical mediators. n-3 PUFAs can reduce inflammation by altering membrane composition, inhibiting pro-inflammatory signaling, and promoting anti-inflammatory responses. n-3 PUFAs are structural descriptors for a family of PUFAs with a double bond near the methyl terminus. They are synthesized in plants but not in animals. EPA and DHA are found in fish and fish oil, and are involved in various inflammatory processes. They influence eicosanoid production, endocannabinoid levels, and inflammatory cytokine production. They also affect T-cell reactivity and inflammatory signaling pathways, including NFκB and PPAR-γ. The anti-inflammatory effects of n-3 PUFAs are mediated through various mechanisms, including receptor activation (GPR120 and PPAR-γ), inhibition of NFκB activation, and production of resolvins and protectins. These effects are supported by studies in cell cultures, animal models, and clinical trials. However, the required dose for significant anti-inflammatory effects is often higher than typical dietary intakes. While n-3 PUFAs are naturally occurring nutrients, their role in pharmacology is being explored due to their ability to modulate inflammatory responses. The distinction between nutrition and pharmacology depends on the dose required to elicit an anti-inflammatory effect.