Omega-6 to omega-3 ratio

This ratio divides linoleic acid, the dominant omega-6 in the diet, by your combined EPA and DHA. It is the single clearest read on this panel of how far a modern diet has shifted the fats your cell membranes are built from.

The two families compete. They use the same desaturase and elongase enzymes, and the molecules made downstream from each pull in opposite directions on inflammatory signalling. What determines the outcome is not the absolute amount of either but the balance between them.

On this panel the in-range band runs to 15, with 2.5 and below treated as optimal. Human diets before industrial seed oils are generally estimated to have sat far closer to the optimal end than the typical result does now.

Below the optimal band means omega-3 is high relative to linoleic acid, which is the direction almost nobody arrives at by accident.

It generally reflects high-dose omega-3 supplementation alongside a diet already low in seed oils. That is not a problem in itself, though it is worth reading with your Omega-3 Index and EPA results to see the whole picture.

Very high combined omega-3 intake extends bleeding time, which matters alongside anticoagulant medication.

At 2.5 or below the balance sits in the optimal band on this panel, and anything up to 15 still reads as in range.

Reaching the optimal end usually takes both moves at once: cutting the linoleic acid coming in, and raising EPA and DHA. Doing only one of them moves the ratio slowly, because the other side of the fraction stays put.

Above 15 the ratio is outside the reference range, and this is the common finding on a Western diet rather than an unusual one.

A high ratio means the omega-6 side dominates. It suppresses what conversion of plant omega-3 precursors would otherwise happen, and shifts the balance of signalling molecules toward the inflammatory side.

It moves slowly. Membrane fat composition turns over across months, so a retest is worth taking after a season rather than after a few weeks.

This is the marker where the Western diet is most legible. Seed oils went from negligible to dominant in the food supply within a few generations, and linoleic acid intake followed, while oily fish consumption fell at the same time.

Both sides of the fraction moved the wrong way at once, which is why this ratio is usually further from optimal than any single fatty acid result would suggest.

Cutting seed oils is the single most effective change. Remove soybean, corn, canola, sunflower and safflower oil from cooking, and read labels on packaged food, where most intake hides.

Raise oily fish to four or more servings a week while the ratio is high: salmon, mackerel, sardines, herring and anchovies.

Cook with extra-virgin olive oil, butter or ghee. Move toward whole foods, grass-fed meat and pastured eggs, which shifts the fat profile without counting anything.

High-dose omega-3 at 3 to 4 g combined EPA and DHA daily while the ratio is out of range, then retest after three to four months and adjust.

Triglyceride-form fish oil absorbs better than ethyl ester. Algal oil is the plant-based equivalent.

No supplement lowers linoleic acid. That side only comes down when intake comes down, which is why diet does the heavy lifting here.