Omega-6:Omega-3 Ratio

The omega-6 to omega-3 ratio, sometimes reported as the arachidonic acid to eicosapentaenoic acid (ARA/EPA) ratio, compares the levels of two key families of fatty acids in your blood. Arachidonic acid is the main omega-6 fatty acid your body uses to produce pro-inflammatory signalling molecules, while eicosapentaenoic acid is an omega-3 fatty acid used to produce anti-inflammatory ones. Both are essential and play important roles, but the balance between them matters more than either in isolation. This test gives you a single number that summarises where that balance currently sits.

Modern Western diets are typically heavily skewed towards omega-6 because of the abundance of refined vegetable oils (sunflower, soybean, corn) in processed foods, relative to omega-3 sources like oily fish. Ancestral diets are thought to have maintained an omega-6 to omega-3 ratio of around 1:1 to 4:1, whereas a typical UK diet often produces a ratio of 15:1 or higher. A high ratio is associated with heightened systemic inflammation, which over time contributes to cardiovascular disease, metabolic dysfunction, joint problems, and cognitive decline.

Your ratio responds primarily to what you eat. Increasing intake of oily fish (salmon, mackerel, sardines, anchovies) or taking EPA/DHA supplements raises the omega-3 side of the equation. Reducing processed foods and refined vegetable oils lowers the omega-6 side. Changes are reflected in cell membrane composition over two to three months. Because the ratio integrates both sides, it is often a more actionable target than either omega-3 or omega-6 alone. Your GP or a registered dietitian can help you set a realistic dietary plan.