Stimulated cytokine production (IL-6 and TNF-α) in peripheral blood mononuclear cells is a more sensitive marker of omega-3’s anti-inflammatory effect than serum cytokine levels in healthy young adults, because baseline serum cytokine levels are too low to detect meaningful changes.

Omega-3 fats from supplements get built into the membranes of immune cells, where they replace other fats that trigger inflammation. When these cells are activated, they produce fewer inflammatory signals because the omega-3 fats change how enzymes work inside the cell. This makes it easier to see the anti-inflammatory effect when measuring what the cells produce in a test, rather than looking at the tiny amounts of inflammation already floating in the blood.