Corn oil or soybean oil: the same omega-6, different vitamin K

Corn oil has served as the placebo in many omega-3 trials, and a network meta-analysis of 17 of them, covering 141,009 patients, used that to test it. In indirect comparisons, EPA cut cardiovascular death by 20% only against mineral oil placebo (hazard ratio 0.80, 95% CI 0.65 to 0.98). Against corn oil or olive oil placebo it made no difference, which says corn oil behaved as neutral and says nothing about it protecting anyone. Against corn oil capsules of a few grams, fish oil lowered triglycerides by 25.5 mg/dL (95% CI 8.6 to 42.4) in a meta-analysis of randomized trials. On the label the two oils are close. Per 100 g in USDA survey data, corn oil has 51.9 g linoleic acid and soybean oil 50.9 g, with saturated fat at 13.4 against 14.9 g. They differ in three places. Soybean oil has 6.62 g of the omega-3 ALA against 1.04 g, corn oil has 22.6 mg vitamin E against 12.2 mg, and soybean oil carries 183.9 ug vitamin K against 1.9 ug. These are refined commodity oils, and high-oleic soybean oil differs sharply.

How much is actually in it

• UK composition data give corn oil 51.3 g polyunsaturated fat per 3.5 oz (100 g), of which 50.4 g is omega-6 and 0.9 g omega-3. — CoFID 2021, Oil, corn (code 17-033) Evidence E source
  Energy 899 calories; PUFA 51.3 g (n-6 50.4 g, n-3 0.90 g); MUFA 29.9 g; saturated 14.4 g per 3.5 oz (100 g)

What a real portion looks like

• Per 100 g, soybean oil has 6.6 g of the omega-3 ALA against 1.0 g in corn oil, while corn oil has almost twice the vitamin E, 22.6 vs 12.2 mg. — US survey foods Corn oil (FNDDS 82102000, fdc 2710183) and Soybean oil (FNDDS 82108000, fdc 2710191) Evidence E source
  Per 100 g corn vs soybean: linoleic acid 51.9 vs 50.9 g; ALA 1.04 vs 6.62 g; MUFA 27.7 vs 22.1 g; saturated 13.4 vs 14.9 g; vitamin E 22.6 vs 12.2 mg; 1 tablespoon 14 g

What your body absorbs

• In 12 women eating salads with 0 to 32 g soybean oil in the dressing, absorption of carotenoids and vitamin K1 rose with the oil dose and peaked at 32 g. — 12 women, each eating 5 vegetable salads with dressings of 0, 2, 4, 8 or 32 g soybean oil (n = 12) Evidence B source
  Linear rise in chylomicron AUC for alpha-carotene, lycopene, phylloquinone and retinyl palmitate across 0-32 g; highest absorption at 32 g (P<0.002); wide individual variation

What it does to your health

• In a 3-month feeding RCT of 90 Chinese women at high cardiovascular risk, cooking with soybean oil gave no different weight change than olive or camellia oil. — 90 middle-aged and elderly Chinese women at high cardiovascular risk; soybean, olive or camellia seed oil for lunch and dinner, 3 months (n = 90) Evidence B source
  Weight change: soybean oil 0.68 lb (95% CI -1.9 to 0.6; metric: 0.31 kg, -0.88 to 0.27), olive oil -0.29 lb (-0.13 kg), camellia oil -1.6 lb (-0.72 kg), no significant group difference; olive oil slightly raised HDL vs soybean oil (P=0.03)
• In a crossover pilot of 10 adults, eating 1.1 oz (30 g) soybean oil a day in foods for 4 weeks nudged blood linoleic acid up without changing body weight. — 4 men and 6 women aged 25-76, BMI 26-41; 30 g/day soybean or palm oil in 3 study foods, 4 weeks each (n = 10) Evidence B source
  Plasma linoleic acid +2.35 (P=0.07) and erythrocyte +1.09 (P=0.05) on soybean oil; -1.60 on palm oil (P=0.04); no weight change (P>0.40)

Safety, limits and interactions

• Soybean oil carries about 184 ug vitamin K per 3.5 oz (100 g), roughly 26 ug per tablespoon, while corn oil has under 2 ug. — US survey foods Corn oil (fdc 2710183) and Soybean oil (fdc 2710191) Evidence E source
  Vitamin K1 per 3.5 oz (100 g): soybean oil 183.9 ug vs corn oil 1.9 ug; per 14 g tablespoon about 25.7 vs 0.3 ug
• The NIH Office of Dietary Supplements names soybean and canola oil among the most common sources of vitamin K in the US diet. — US diet, NIH ODS Vitamin K fact sheet for health professionals Evidence E source
  Soybean oil listed with spinach, broccoli and iceberg lettuce as main US vitamin K sources

What people believe that the data does not support

• A meta-analysis of RCTs that used corn oil as the comparison found fish oil lowered triglycerides by about 25 mg/dL more than corn oil, with no difference in LDL. — Randomized trials of fish oil supplements with corn oil as control, searched to December 2022 Evidence A source
  TG -25.50 mg/dL (95% CI -42.44 to -8.57); HDL +2.54 mg/dL (0.55 to 4.52); total cholesterol and LDL not different
• A network meta-analysis of 17 RCTs with 141,009 patients found EPA cut cardiovascular death by 20% only against mineral oil placebo, not against corn oil or olive oil placebo. — 17 omega-3 RCTs; 8,876 patients on corn oil placebo, 41,009 on olive oil, 5,338 on mineral oil (n = 141009) Evidence A source
  EPA vs mineral oil: CV death HR 0.80 (95% CI 0.65-0.98), MI HR 0.73, stroke HR 0.74; no difference vs corn oil, olive oil or no placebo
• The EU register lists the claim that corn oil helps control blood cholesterol as non-authorized, and has no soybean oil claim at all. — EU Register on nutrition and health claims, snapshot 2026-09-21 Evidence E source
  Corn oil: 0 authorized, 1 non-authorized; soybean oil: no entries

Who this works differently for

• Across 9 cohorts with 382,094 adults, higher linoleic acid intake was linked to 11% lower hip fracture risk, and the authors suggest 9-16 g a day, which they equate to 2-3 tablespoons of corn oil. — 9 prospective cohorts, 382,094 adults, 12,392 hip fractures, follow-up 7-24 years (n = 382094) Evidence C source
  Linoleic acid HR 0.89 (95% CI 0.82-0.96); saturated fat HR 1.20 (1.08-1.33)

The bottom line

UK composition data give a second number for corn oil, 50.4 g omega-6 and 0.9 g omega-3 per 3.5 oz (100 g), within 1 g of the US figures. The UK dataset has no soybean oil entry. Oil helps a salad do its job. In 12 women eating vegetable salads dressed with 0 to 32 g soybean oil, absorption of alpha-carotene, lycopene and vitamin K1 rose in a straight line with the oil, a small study that did not test corn oil. On weight, soybean oil has two small trials. In 90 Chinese women at high cardiovascular risk, 3 months of cooking with soybean, olive or camellia oil gave no significant difference in weight change. In a 4-week crossover pilot of 10 adults eating 1.1 oz (30 g) soybean oil a day in foods, blood linoleic acid tended to rise without reaching significance, and weight did not change. The long-term data is observational. Across 9 cohorts with 382,094 adults, higher linoleic acid intake was linked to an 11% lower hip fracture risk (hazard ratio 0.89, 95% CI 0.82 to 0.96), with residual confounding possible. The authors put the helpful range at 9 to 16 g a day, which they equate to 2 to 3 tablespoons of corn oil. The EU register lists a claim that corn oil helps control blood cholesterol as non-authorized, meaning the evidence was insufficient at assessment, and it has no soybean oil entry at all. We found no human study of what frying does to either oil. The caution is vitamin K, and it separates the two oils. A 14 g tablespoon of soybean oil has about 26 ug against 0.3 ug for corn oil, recalculated from the 100 g values. The NIH Office of Dietary Supplements names soybean and canola oil among the most common vitamin K sources in the US diet. People on warfarin are advised to keep vitamin K intake steady, so switching between these two oils is worth mentioning to whoever manages the dose. Nothing on this page covers soy or corn allergy.

Sources

1. cosb-daily-r7-03 · dataset
   Oil, corn, CoFID 17-033: Energy (kcal) 899; Poly FA /100g food (g) 51.30; n-6 poly /100g food (g) 50.40; n-3 poly /100g food (g) 0.90; Mono FA /100g food (g) 29.90; Satd FA /100g fd (g) 14.40
   CoFID 2021, Public Health England, OGL v3.0 · checked 2026-09-30
2. cosb-daily-r7-01 · dataset
   Corn oil, fdc_id 2710183: PUFA 18:2 51.9 G; PUFA 18:3 1.04 G; Fatty acids, total monounsaturated 27.7 G; Fatty acids, total saturated 13.4 G; Vitamin E (alpha-tocopherol) 22.6 MG per 100 g. Soybean oil, fdc_id 2710191: PUFA 18:2 50.9 G; PUFA 18:3 6.62 G; Fatty acids, total monounsaturated 22.1 G; Fatty acids, total saturated 14.9 G; Vitamin E (alpha-tocopherol) 12.2 MG per 100 g. 1 tablespoon 14 g
   USDA FoodData Central, FNDDS survey foods, release 2024-10-31 · checked 2026-09-30
3. cosb-daily-r7-05 · RCT
   Across the entire 0-32-g range, soybean oil was linearly related to the chylomicron AUC and Cmax values for α-carotene, lycopene, phylloquinone, and retinyl palmitate.
   Am J Clin Nutr, 2017 · checked 2026-09-30
4. cosb-daily-r7-06 · RCT
   We found no significant difference in the changes of body weight among the SO group (mean change, 0.31 kg; 95% CI, -0.88 to 0.27), the OO group (mean change, -0.13 kg; 95% CI, -0.62 to 0.36), and the CSO group (mean change, -0.72 kg; 95% CI, -1.38 to -0.07).
   Food Funct, 2022 · checked 2026-09-30
5. cosb-daily-r7-07 · RCT
   After 4 wk of consuming 3 foods/d, plasma linoleic acid decreased during the palm oil intervention (-1.60, P = 0.04), whereas it tended to increase in plasma (2.35, P = 0.07) and erythrocytes (1.09, P = 0.05) during the soybean oil intervention.
   J Nutr, 2026 · checked 2026-09-30
6. cosb-daily-r7-02 · dataset
   Corn oil, fdc_id 2710183: Vitamin K (phylloquinone) 1.9 UG per 100 g. Soybean oil, fdc_id 2710191: Vitamin K (phylloquinone) 183.9 UG per 100 g
   USDA FoodData Central, FNDDS survey foods, release 2024-10-31 · checked 2026-09-30
7. cosb-daily-r7-04 · agency fact sheet
   The most common sources of vitamin K in the U.S. diet are spinach; broccoli; iceberg lettuce; and fats and oils, particularly soybean and canola oil [5,7].
   NIH Office of Dietary Supplements, Vitamin K Health Professional Fact Sheet · checked 2026-09-30
8. cosb-daily-r7-08 · meta-analysis of RCTs
   The results revealed that the fish oil supplements significantly reduced TG (WMD: - 25.50 mg/dl, 95% CI: - 42.44, - 8.57, P = 0.000) levels compared to corn oil.
   Syst Rev, 2024 · checked 2026-09-30
9. cosb-daily-r7-09 · network meta-analysis
   Rates of cardiovascular death [hazard ratio (HR) (95% confidence interval, CI) =0.80 (0.65-0.98); p =0.033], myocardial infarction [HR (95% CI) =0.73 (0.55-0.97); p=0.029] and stroke [HR (95% CI) =0.74 (0.58-0.94); p=0.014] were significantly lower in those receiving EPA compared to those receiving mineral oil, but were not different from rates in those receiving other oils or controls.
   J Cardiol, 2022 · checked 2026-09-30
10. cosb-daily-r7-11 · regulatory decision
    POL-HC-6985 Corn Oil with a guaranteed polyunsatured fatty acids content (56% of total fatty acids), supplemented with vitamin E. 1- When used within a healthy, balanced diet, in combination with a healty lifestyle, corn oil with an elevated vitamin E content and a guaranteed polyunsaturates fatty acids content contributes to the control of blood cholesterol. 2-When used within a healthy, balanced diet, in combination with a healty lifestyle, corn oil contributes to the control of blood cholesterol. 3-As a part of a healthy lifesyle, corn oil helps to maintain normal blood cholesterol level.4-As a part of a healthy lifesyle, corn oil helps to keep blood cholesterol levels under control. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-6985, snapshot 2026-09-21 · checked 2026-09-30
11. cosb-daily-r7-10 · meta-analysis of cohorts
    These findings suggest that consuming 9-16 g of linoleic acid (LA) daily (equivalent to 2-3 tablespoons of corn oil or 30-60 g of walnuts) and maintaining elevated blood levels of omega-3 fatty acids, especially eicosapentaenoic acid (EPA), may help reduce the risk of hip fractures.
    Osteoporos Int, 2025 · checked 2026-09-30