Salmon: wild against farmed, measured rather than assumed

Wild salmon is supposed to carry more omega-3 than farmed. Measured the same way, baked, per 100 grams, the British composition tables give wild salmon 2.64 grams of omega-3 and farmed salmon 3.10. The farmed fish has more. What the wild one has more of is vitamin D, 10.3 micrograms against 7.3, and selenium, 32 against 20, while the farmed one also carries more omega-6, 0.74 grams against 0.31. The two fish are different, and they differ in those four numbers rather than in the one the argument is usually about. A trial explains why. Salmon fed on fish oil carried 2.1 grams of EPA and DHA per 100 grams, salmon fed on rapeseed oil carried 0.9, so the feed sets the content. Then people ate two portions a week for 18 weeks, and the omega-3 index in their blood rose by the same amount from either fish. More than double the difference in the fillet, no difference in the blood.

The numbers, per 100 g

How much is actually in it

• Baked farmed salmon carried more omega-3 than baked wild salmon, not less. What the wild fish had more of was vitamin D and selenium, and what the farmed one had more of, besides omega-3, was omega-6. — Salmon, wild, baked and Salmon, farmed, flesh only, baked (n = CoFID 2,886 foods and 142,881 values) Evidence E source
  Per 100 g, wild baked salmon (16-485): 215 kcal, 12.1 g fat, 26.5 g protein, 2.64 g n-3 polyunsaturates, 0.31 g n-6, 32 µg selenium, 10.3 µg vitamin D. Farmed baked salmon (16-359): 232 kcal, 14.6 g fat, 25.2 g protein, 3.10 g n-3, 0.74 g n-6, 20 µg selenium, 7.3 µg vitamin D
• Even within farmed Atlantic salmon the omega-3 content swings by half between samples, and iron by nearly three times. Wild salmon is not in the dataset at all, so nobody can say how much it varies. — Fish, salmon, Atlantic, farm raised, raw (n = 8 samples) Evidence E source
  EPA 0.318 g mean ranging 0.228 to 0.430 across 8 samples, a spread of 64%; DHA 0.585 g ranging 0.488 to 0.739, spread 43%; total polyunsaturates 4.061 g ranging 2.999 to 5.706, spread 67%; iron 0.2588 mg ranging 0.0 to 0.444, spread 172%; iodine 3.242 µg ranging 1.494 to 5.557, spread 125%; protein 20.3 g, spread 11%; potassium 378.2 mg, spread 19%

What a real portion looks like

• A regular grilled salmon fillet weighs 140 grams and a large one 210. The four-ounce serving regulators talk about is 113 grams, so an ordinary fillet is already more than one serving. — Fish, salmon, grilled, in the WWEIA category Fish (n = FNDDS 5,432 foods and 22,046 household measures) Evidence E source
  Fish, salmon, grilled (fdc_id 2706287, FNDDS code 26137123): 1 small or regular fillet 140 g, 1 large fillet 210 g, 1 steak 210 g, 1 cup 135 g, 1 oz yields 20 g, 1 cubic inch 17 g, quantity not specified 140 g

What your body absorbs

• A whole piece of salmon delivered more omega-3 into the blood than the same salmon minced, and more than the same fat served as oil alongside defatted fish. The meals were matched nutrient for nutrient. Only the structure differed. — healthy female participants (n = 13 women, each eating all three meals) Evidence B source
  Three meals with identical macronutrient composition were compared, intact salmon with full structure, minced salmon with some structure and defatted salmon plus oil with no structure; plasma eicosapentaenoic acid and docosahexaenoic acid were significantly higher after intact salmon than after the other two meals, with covariate analysis p < 0.001
• The reason whole fish works better is mechanical. Fat from the unstructured meal emptied out of the stomach faster, while the intact fish held it back and let it separate out slowly. — the same three meals used in the human arm (n = three meals, in vitro digestion alongside 13 human participants) Evidence B source
  The defatted salmon plus oil meal showed a faster fall in pH and faster fat emptying from the gastric simulator than the other two meals and behaved like a homogeneous unstructured meal, while intact and minced salmon showed phase separation with delayed fat emptying; the authors conclude the fish matrix plays an important role in bioaccessibility and bioavailability of EPA and DHA, partly explained by fat digestion and gastric emptying

What cooking and storage change

• How much omega-3 survives cooking a salmon is a question the standard reference cannot answer. Omega-3 is not in it. Neither is vitamin D, nor selenium, which are the other two reasons people eat the fish. — Finfish and Shellfish Products, methods for fish above 5% fat (n = the table carries exactly 26 nutrients, of which 16 are parsed into our layer and 10 skipped with a stated reason; 40 finfish methods exist, 8 of them for fish above 5% fat) Evidence E source
  Omega-3 is absent from the USDA retention table entirely, as are vitamin D, selenium, vitamin K, vitamin E, manganese, iodine, protein and fibre; what the table does give for FINFISH,>5%FAT,BAKED,W/DRIPPINGS (2452) is vitamin B12 retained at 80%, vitamin C at 85%, vitamin B6 at 95%, folate at 95% and every mineral at 100%

What it does to your health

• Salmon fed on rapeseed oil carried less than half the omega-3 in its flesh compared with salmon fed on fish oil. After eighteen weeks of eating it twice a week, people's blood omega-3 had risen by the same amount either way. — healthy adults eating two portions a week as part of their habitual diet (n = 51 healthy subjects, 17 per arm) Evidence B source
  Fillets from fish-oil-fed salmon contained 2.1 g of EPA plus DHA per 100 g against 0.9 g for rapeseed-oil-fed salmon; after 18 weeks the omega-3 index was similarly increased in both salmon groups against control (both p < 0.05), serum 25-hydroxyvitamin D3 was significantly higher and plasma triacylglycerols significantly lower in the rapeseed-oil salmon group against control, and heart rate was significantly lower in the fish-oil salmon group at 9 weeks
• Eight weeks of the recommended amount of salmon did not move any headline cholesterol number in young women with excess weight. The only thing that differed was the direction of travel: LDL drifted down in the salmon group and up in the group without it. — women aged 18 to 30 with BMI of 25 or above, 47% of whom had at least one lipid parameter outside the recommended range at baseline (n = 38 women) Evidence B source
  No statistically significant differences were observed between groups after 8 weeks in total cholesterol, HDL, non-HDL, LDL or triglycerides, nor in the atherogenic indices; the change in LDL differed, falling 8.2 plus or minus 20.7 mg/dL in the intervention group against a rise of 9.5 plus or minus 20.0 in controls (p = 0.011), as did the change in Cholindex; among participants with waist-to-height ratio above 0.5, triglycerides rose 50.0 plus or minus 68.3 mg/dL in the intervention group and fell 8.6 plus or minus 56.6 in controls (p = 0.040)

Safety, limits and interactions

• Farmed fish is not mercury-free, and a review of eighteen studies concluded it generally carries less than fish caught in the wild, because a pond is easier to control than an ocean. Salmon was not among the species it looked at most. — farmed fish from seven countries: China, Korea, Pakistan, India, Brazil, the USA and Poland; 50 farmed species evaluated worldwide (n = 18 articles, 50 species) Evidence C source
  Mercury values in fish from production systems were low, and in the risk analysis only India showed values within tolerable limits while Korea and Pakistan showed high values indicating potential risk; the review concludes that farmed fish are not mercury-free but safer than fish in nature owing to greater control of biotic and abiotic factors in ponds

What people believe that the data does not support

• Europe lets you make a dozen health claims about the omega-3 fats in salmon and not one about salmon. The only claim ever filed for it, about salmon oil and cholesterol, was turned down. — claims filed for authorisation on omega-3 fatty acids and on salmon in the European Union (n = 82 claims mention EPA, of which 3 authorised; 54 mention DHA, of which 9 authorised; 1 mentions salmon, non-authorised) Evidence E source
  Authorised for the fatty acids include POL-HC-6368 EPA and DHA contributing to normal heart function, POL-HC-8354 to maintenance of normal blood pressure, POL-HC-8362 to normal blood triglyceride levels, and for DHA alone normal brain function, normal vision, and maternal intake contributing to normal brain and visual development of the foetus and breastfed infant; the only claim filed on salmon itself, POL-HC-7853 for pure salmon oil 500 mg with D alpha tocopherol supporting normal blood cholesterol, is recorded as Non-authorised

Who this works differently for

• American regulators put salmon on the Best Choices list and tell people who are pregnant or breastfeeding to eat two to three servings of such fish a week. A serving is four ounces, which is about a small fillet. — those who might become or are pregnant or breastfeeding, and children aged 1 to 11 years (n = advice covering the commonly eaten fish in the United States) Evidence E source
  The advice is to eat 2 to 3 servings a week from the Best Choices list, with 1 serving being 4 ounces for pregnancy and breastfeeding and servings for children ranging from about 1 ounce at ages 1 to 3 up to 4 ounces at age 11; salmon is listed in the Best Choices category

The bottom line

Eat the fish itself rather than a spoonful of oil where you have the choice. In a crossover trial, three meals matched nutrient for nutrient, a whole fillet, the same fish minced, and defatted fish with its oil served alongside, put different amounts of EPA and DHA into the blood, and the whole fillet came out highest. The reason is mechanical. Fat from the unstructured meal emptied out of the stomach quickly, while the intact fish held it back and let it separate slowly. Portions are smaller than the fish in front of you. American regulators list salmon among the Best Choices and tell people who are pregnant or breastfeeding to eat two or three servings a week, and a serving is four ounces, 113 grams. An ordinary grilled fillet weighs 140 grams, so one fillet is already more than one serving. Do not expect it to move your cholesterol in two months. Eight weeks of the recommended amount in young women with excess weight changed no headline lipid number, and the only thing that differed was which way LDL drifted. What cooking does to the omega-3 is a question our standard reference cannot answer, because omega-3 is not in it. Neither is vitamin D, nor selenium. The three reasons people eat this fish are all missing from the table that tells you what cooking costs. What that table does say for baked oily fish is that B12 holds at 80 percent and every mineral at 100. Two honest notes to close on. Farmed fish is not mercury-free, and the review that found it generally carries less than wild fish did not have salmon among the species it studied most, so we are not passing that conclusion on as though it were about salmon. And even inside farmed Atlantic salmon, EPA swings by 64 percent between samples. Wild salmon is not in that dataset at all, so how much it varies is nobody's knowledge.

Sources

1. sal-f-08 · reference dataset
   CoFID 16-485 Salmon, wild, baked — Energy 215 kcal · Fat 12.1 g · Protein 26.5 g · n-3 poly /100g food 2.64 g · n-6 poly /100g food 0.31 g · Selenium 32 µg · Vitamin D 10.3 µg || CoFID 16-359 Salmon, farmed, flesh only, baked — Energy 232 kcal · Fat 14.6 g · Protein 25.2 g · n-3 poly /100g food 3.10 g · n-6 poly /100g food 0.74 g · Selenium 20 µg · Vitamin D 7.3 µg
   CoFID 2021, Public Health England / OGL v3.0 · checked 2026-09-21
2. sal-f-10 · reference dataset
   Fish, salmon, Atlantic, farm raised, raw — PUFA 20:5 n-3 (EPA) 0.318 G діапазон 0.228–0.43, зразків 8, розкид 64% · PUFA 22:6 n-3 (DHA) 0.585 G діапазон 0.488–0.739, зразків 8, розкид 43% · Fatty acids, total polyunsaturated 4.061 G діапазон 2.999–5.706, зразків 8, розкид 67% · Iron, Fe 0.2588 MG діапазон 0.0–0.444, зразків 8, розкид 172% · Iodine, I 3.242 UG діапазон 1.494–5.557, зразків 8, розкид 125% · Potassium, K 378.2 MG розкид 19%
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-21
3. sal-f-11 · reference dataset
   FNDDS 2706287 Fish, salmon, grilled (26137123, Fish) — 1 small/regular fillet 140 г · 1 large fillet 210 г · 1 steak 210 г · 1 cup 135 г · 1 oz yields 20 г · 1 cubic inch 17 г · Quantity not specified 140 г
   USDA FNDDS 2021-2023, FoodData Central · checked 2026-09-21
4. sal-f-01 · randomised crossover trial
   Results: showed that plasma concentration of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were significantly higher after participants consumed intact salmon compared to the other meals (covariate analysis p < 0.001).
   Food and Function, 2021 · checked 2026-09-21
5. sal-f-02 · in vitro digestion alongside a randomised crossover trial
   Conclusion: The fish matrix (salmon) plays an important role in the bioaccessibility and bioavailability of EPA and DHA. The differences are partly explained by fat digestion and emptying from the stomach.
   Food and Function, 2021 · checked 2026-09-21
6. sal-f-09 · reference dataset
   USDA-RETN-R6:2452 FINFISH,>5%FAT,BAKED,W/DRIPPINGS — vitamin_b12_ug 80% · vitamin_c_mg 85% · vitamin_b6_mg 95% · folate_total_ug 95% · calcium_mg 100% · iron_mg 100% · magnesium_mg 100% · potassium_mg 100% · zinc_mg 100% || «omega» у таблиці ретенції USDA НЕМАЄ · немає також вітаміну D, селену, вітаміну K, вітаміну E, марганцю, йоду, білка й клітковини
   USDA Table of Nutrient Retention Factors, Release 6 (2007), Agricultural Research Service · checked 2026-09-21
7. sal-f-03 · randomised parallel controlled trial
   Salmon were grown on feeds containing mainly fish oil (FO) or rapeseed oil (RO), resulting in an eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) content of fillets of 2.1 or 0.9 g/100 g, respectively...After 18 weeks, O3I was similarly increased in subjects consuming 2 portions/week of FO or RO salmon compared to control (both p < 0.05).
   European Journal of Nutrition, 2021 · checked 2026-09-21
8. sal-f-05 · randomised controlled trial
   No statistically significant differences were observed in the TC, HDL, non-HDL, LDL, or TAG concentrations or in the various atherogenic indices between the intervention and the control group after the 8-week-long intervention.
   Nutrients, 2024 · checked 2026-09-21
9. sal-f-04 · systematic review
   Therefore, farmed fish are not Hg-free but safer than fish in nature due to greater control of biotic and abiotic factors in ponds, thus contributing to sustainable, productive economic activity.
   Biological Trace Element Research, 2025 · checked 2026-09-21
10. sal-f-07 · regulatory register
    POL-HC-6368 Eicosapentaenoic acid and docosahexaenoic acid (EPA/DHA) EPA and DHA contribute to the normal function of the heart Authorised
    EU Register on nutrition and health claims, European Commission · checked 2026-09-21
11. sal-f-06 · agency dietary advice
    Eat 2 to 3 servings a week from the "Best Choices" list
    US FDA and EPA, Advice about Eating Fish · checked 2026-09-21