Razão Ômega-6 / Ômega-3

Omega-6 to omega-3 ratio: from 15:1 (modern) toward 4:1 (ancestral)

The omega-6 : omega-3 ratio compares two essential polyunsaturated fat families. The industrialized Western diet sits around 15–20 : 1, an excess of omega-6 (linoleic acid from soy, corn, sunflower and cottonseed oils) over omega-3. The ancestral / paleolithic ratio is estimated at 1–4 : 1, and many researchers (Simopoulos, 2002 onward) tie the modern excess to chronic low-grade inflammation. Take an example: 12 g of omega-6 against 1.5 g of omega-3 gives a ratio of 8:1, better than average but still on the high side. Two levers help. Raise omega-3 with fatty fish like salmon and sardine, plus flaxseed, chia and walnut, and lower omega-6 by cutting industrial seed oils and ultra-processed snacks. One caveat: long-chain omega-3 (EPA/DHA) comes from fish or algae oil, while the plant form (ALA in flax and chia) converts to EPA at only ≈ 5% in humans. Formula: ratio = ω6 (g) / ω3 (g).

Applications: cardiovascular nutrition, anti-inflammatory diet, pregnancy, mood

The ratio guides cardiovascular nutrition (lower triglycerides, antiarrhythmic effect of EPA/DHA), anti-inflammatory protocols (rheumatic disease, IBD), pregnancy (DHA is structural for fetal brain and retina, with a recommendation of ≈ 200 mg DHA/day), depression (omega-3 as adjuvant in major depression, per APA, 2019) and ARDS / critical care (some protocols use enteral formulas enriched with EPA). A practical rule of thumb: two portions of fatty fish a week, daily ground flax or chia, and seed oils swapped for olive oil.

FAQ

Is the ideal ratio really 4:1? There's no single official target; cited values run anywhere from 1:1 to 4:1. Many bodies, the AHA among them, would rather set an absolute target: at least 2 portions of fatty fish per week.

Does omega-6 cause inflammation? Mechanistically, linoleic acid is a precursor of arachidonic acid, which is pro-inflammatory, yet RCTs show neutral or even beneficial CVD effects. The "excess omega-6" hypothesis remains debated.

Is flaxseed enough for omega-3? It provides ALA, but conversion to EPA/DHA is poor (≈ 5–10% to EPA, < 1% to DHA). Vegans and vegetarians should consider algae DHA.

How much fish oil per day? Common doses range from 250 mg EPA+DHA for general health up to 1–4 g in clinical settings under guidance, since high doses raise bleeding risk.