The Omega-6 : Omega-3 ratio explained
It shows up on every Plus Ratios and Complete report — a single number that captures the long-term balance of your dietary fats. Useful, sometimes misunderstood, and easier to move than it looks.
What it actually measures
The omega-6 : omega-3 ratio is the total of all measurable omega-6 fatty acids — mainly linoleic acid (LA), with a smaller contribution from arachidonic acid (AA) — divided by the total of all measurable omega-3 fatty acids — mainly EPA, DHA, ALA and DPA. It is a snapshot of how your diet over the last 3–4 months has skewed between two competing families of polyunsaturated fats.
Because LA is the dominant omega-6 in the Australian food supply, the ratio is largely a marker of how much refined seed oil and ultra-processed food you eat versus how much oily fish, algae or supplemental EPA+DHA you take in.
What the ratio looks like in practice
Why it matters
Omega-6 (especially AA) and omega-3 (especially EPA) compete for the same enzymes — the cyclooxygenases (COX), lipoxygenases (LOX) and the desaturases that elongate them into longer-chain forms. When omega-6 dominates the substrate pool, those enzymes preferentially produce AA-derived eicosanoids, many of which are pro-inflammatory, pro-aggregatory and vasoconstrictive.
Higher long-term omega-6 : omega-3 ratios have been associated in observational research with elevated cardiovascular risk, autoimmune flare patterns and chronic low-grade inflammation. Simopoulos's 2002 review remains the most cited framing of this; Patterson et al.'s 2012 review walks through the mechanistic and epidemiological evidence in more detail.
How to improve it
- Increase EPA+DHA from oily fish, algae or supplements — by far the most effective lever.
- Switch your cooking oil from sunflower, canola or soybean to extra-virgin olive oil for everyday use.
- Reduce ultra-processed foods — most processed food in Australia carries a heavy LA load from refined seed oils.
- Don't try to avoid all omega-6. LA is an essential fatty acid and effectively impossible to remove from a normal diet. Focus on the ratio, not the absence.
What improvement looks like over time
Because the ratio reflects red blood cell composition, you need roughly 3–4 months of consistent intake change before it meaningfully shifts in your blood. Most people who start at around 8:1 can move to 5:1 within four months on roughly 1,500 mg/day of EPA+DHA, with diet held otherwise constant. The standard retest cadence is 3–4 months.
Test your ratios
Order Plus Ratios →References: Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 2002. · Patterson E et al. Health implications of high dietary omega-6 polyunsaturated fatty acids. J Nutr Metab. 2012. · Marklund M et al. Biomarkers of dietary omega-6 fatty acids and incident cardiovascular disease and mortality. Circulation. 2019. · Innes JK, Calder PC. Omega-6 fatty acids and inflammation. Prostaglandins Leukot Essent Fatty Acids. 2018.