Silent inflammation: the lever we forget
Excess adipose tissue is not neutral: it releases inflammatory molecules that make cells deaf to insulin and leptin. Omega-3s are one of the few documented levers to break this cycle.
Verified sources: Nutrients 2024, American Journal of Clinical Nutrition 2023, Circulation 2024.
Adipose tissue, an endocrine organ
Long considered a mere reservoir, adipose tissue is now recognised as an active endocrine organ. In excess, it releases pro-inflammatory adipokines and cytokines (TNF-α, IL-6, resistin) that impair insulin signalling and amplify hunger.
This is metabolic inflammation, or meta-inflammation: low-grade, chronic, silent, but sufficient to sustain weight gain and increase cardiovascular risk.
The omega-6 / omega-3 ratio
Omega-6 (sunflower, corn oils, processed foods) and omega-3 (oily fish, rapeseed, flaxseed) are both essential. The problem is their imbalance: the modern Western diet reaches a 15:1 ratio, sometimes 20:1, while the ancestral ratio is estimated at 4:1 or less.
This imbalance tips the balance of lipid mediators toward pro-inflammatory prostaglandins and leukotrienes. Reducing industrial oils and increasing marine omega-3 is the most effective lever for restoring balance.
EPA and DHA: the thresholds that count
Recent intervention studies converge on a minimum threshold of 1 g EPA + DHA combined per day, for at least 12 weeks, to see a measurable effect on inflammatory markers (hs-CRP, IL-6). The optimal erythrocyte omega-3 index is above 8%.
Food sources: sardines, mackerel, herring (small oily fish, low in pollutants), 2 to 3 portions per week. In supplementation: EPAX- or IFOS-quality fish oil, or algae oil (vegan option, rich in DHA).
Effect on satiety and body composition
2023-2024 data (Nutrients, successive meta-analyses) document in overweight people a modest but real effect of omega-3 on: waist reduction, improved leptin sensitivity, lower triglycerides, and measurable visceral fat loss on DEXA.
Not a magic wand. The effect is around 1 to 2 kg of fat mass in 6 months at constant diet. But combined with other levers, it counts.
What to avoid in parallel
Raising omega-3 without cutting industrial omega-6 leaves the ratio unchanged. Practically: reduce refined sunflower and corn oils, margarines, industrial biscuits, repeated fried foods. Prefer olive oil for gentle cooking, rapeseed oil for dressings.
Prolonged cooking destroys part of the omega-3: prefer steamed sardines, canned in water, or fish half-cooked.
Scientific sources
- · Calder, Nutrients, 2024 — Omega-3 fatty acids and inflammation
- · Harris & Von Schacky, Prev Med, 2004 — Omega-3 index (landmark)
- · Del Gobbo et al., JAMA Internal Medicine, 2016 — Omega-3 and metabolic health
The erythrocyte omega-3 index is a simple test rarely prescribed. We include it systematically in our metabolic consultations, with individual dietary guidance and, if needed, supplementation.
Book a work-upFound this article useful?
Share it with someone who might need it.
Go further
Frequently asked questions
- Does flax oil replace marine omega-3?
- Partially. Flax oil contains ALA, which the body converts poorly (less than 5%) to EPA and DHA. For a real inflammatory effect, marine omega-3 (oily fish, algae oil) remains superior.
- How long to see an effect?
- Biological markers (omega-3 index, hs-CRP) evolve in 8 to 12 weeks. Clinical body composition effects show over 6 months.
- Are omega-3 capsules reliable?
- Quality varies widely. Look for EPAX, IFOS or Nutrasource labels, with clearly stated EPA + DHA dosage and freshness date (peroxide index).
- Should we fear heavy metals in fish?
- In large predators (tuna, swordfish, shark), yes. Small oily fish (sardines, mackerel, anchovies) accumulate very little mercury and remain fully recommended.
- Can vegetarians reach a good omega-3 index?
- Difficult without supplementation. Algae oil is the best option: it provides directly available DHA, without going through the inefficient ALA conversion.