Corn oil and sunflower oil: two omega-6 oils, and a sunflower that changed

The strongest trial evidence on corn oil uses it as the comparison. Across 16 randomized trials, fish oil lowered triglycerides by 25.5 mg/dL more than corn oil (95% CI 8.6 to 42.4) and raised HDL by 2.5 mg/dL more, with no difference in LDL or total cholesterol. Corn oil served as the control arm in those trials, so the result mostly describes fish oil. The bottle matters more than the plant name for sunflower oil. The UK food table lists classic sunflower oil at 63.2 g of omega-6 fat per 3.5 oz (100 g), more than the 50.4 g in corn oil. The sunflower oil in US survey data is a high-oleic type with 63.4 g of monounsaturated fat and 20.7 g of polyunsaturated fat per 3.5 oz (100 g). Both kinds are sold under the same name.

How much is actually in it

• The UK food table lists ordinary sunflower oil as the more linoleic of the two, with 63.2 g omega-6 per 3.5 oz (100 g) against 50.4 g in corn oil, the opposite of the high-oleic sunflower oil in US data. — CoFID 2021 codes 17-033 (Oil, corn) and 17-045 (Oil, sunflower) Evidence E source
  Per 100 g corn vs sunflower: n-6 poly 50.4 vs 63.2 g; mono 29.9 vs 20.5 g; n-3 poly 0.9 vs 0.1 g; vitamin E 17.24 vs 49.22 mg

What a real portion looks like

• In USDA survey data corn oil is 52.9% polyunsaturated fat and 13.4% saturated, while the sunflower oil listed is a high-oleic type with 63.4% monounsaturated fat and three times more vitamin E. — US survey foods, FNDDS Corn oil (code 82102000, fdc_id 2710183) and Sunflower oil (fdc_id 2710192) Evidence E source
  Per 100 g corn vs sunflower: PUFA 52.9 vs 20.7 g; linoleic 18:2 51.9 vs 20.6 g; MUFA 27.7 vs 63.4 g; SFA 13.4 vs 8.99 g; vitamin E 22.6 vs 68.48 mg; 1 tablespoon = 14 g

What cooking and storage change

• In a crossover trial in 19 healthy men, a meal with sunflower-palm olein oil reheated for 10 days of frying did not acutely impair blood vessel function compared with fresh oil. — 19 healthy men, single high-fat meals; oil heated at 180 C over 10 days (23.8% vs 7.2% polar compounds) (n = 19) Evidence B source
  FMD and arterial stiffness comparable; postprandial TAG rise lower after heated oil (p < 0.001)

What it does to your health

• Across 16 RCTs that used corn oil as the comparison, fish oil lowered triglycerides by 25.5 mg/dL and raised HDL by 2.5 mg/dL more than corn oil, with no difference in LDL or total cholesterol. — adults in 16 randomized trials with corn oil as control (491 participants per full text) (n = 16 RCTs) Evidence A source
  TG WMD -25.50 mg/dL (95% CI -42.44 to -8.57); HDL +2.54 mg/dL (0.55 to 4.52); TC and LDL ns
• In an 8-week RCT in 118 men with one FADS1 genotype, 2 to 3.4 tbsp (30 to 50 mL) a day of sunflower oil lowered lipoprotein(a) by 9.5%. Camelina oil lowered it by 7.3%, and the two did not differ significantly. — 118 men homozygous for FADS1 rs174550, 8-week diets with 30-50 mL/day oil (n = 118) Evidence B source
  Lp(a) -9.5% with sunflower oil (p < 0.001) vs -7.3% with camelina oil (between-diet p = 0.089); LDL-C, non-HDL-C, apoB lowered more by camelina (p < 0.01)
• A scoping review for the Nordic Nutrition Recommendations 2023 found canola oil may lower LDL cholesterol compared with sunflower oil, and ranked unsaturated oils above butter and tropical oils. — systematic reviews and meta-analyses on fats and oils at food level Evidence C source
  Direction only; all included reviews of low methodological quality

What people believe that the data does not support

• The EU did not authorize claims that corn oil, even with guaranteed polyunsaturated fat and added vitamin E, helps control or maintain normal blood cholesterol. — EU Register on nutrition and health claims, claim POL-HC-6985 Evidence E source
  Status Non-authorized

Who this works differently for

• Observational data from 15 cohorts in 511,622 men show no link between dietary linoleic acid, the main fat in corn and classic sunflower oil, and prostate cancer risk. — 15 prospective cohorts, 511,622 men, 39,993 prostate cancer cases, follow-up 5-21 years (n = 511622) Evidence C source
  Dietary LA RR 1.00 (95% CI 0.97 to 1.04) total prostate cancer; tissue LA RR 0.86 (0.77 to 0.96)

The bottom line

Corn oil in the US table is 52.9 g polyunsaturated and 13.4 g saturated fat per 3.5 oz (100 g), and a tablespoon weighs 14 g. The high-oleic sunflower oil carries about three times its vitamin E, 68.5 mg against 22.6 mg per 3.5 oz (100 g). In an 8-week randomized trial in 118 men carrying one specific FADS1 gene variant, a diet adding 2 to 3.4 tbsp (30 to 50 mL) a day of a linoleic acid rich oil lowered lipoprotein(a) by 9.5 percent. A camelina oil lowered it by 7.3 percent, and the gap between the two did not reach significance. Camelina lowered LDL cholesterol more. These are blood markers over two months in men only. A review of reviews for the Nordic Nutrition Recommendations found canola oil may lower LDL cholesterol compared with sunflower oil, and every review it drew on was of low methodological quality, so read that as a direction without a size. Across 15 cohorts in 511,622 men, dietary linoleic acid, the main fat in corn and classic sunflower oil, showed no link with prostate cancer (RR 1.00, 95% CI 0.97 to 1.04). That finding concerns the nutrient, and no oil was tested as a food. For frying, a crossover trial in 19 healthy men found that a sunflower and palm olein blend reheated over 10 days of frying at 180 C did not acutely worsen blood vessel function after one meal compared with fresh oil. It was a blend and a single meal. The EU did not authorize claims that corn oil, even with guaranteed polyunsaturated fat and added vitamin E, helps control blood cholesterol. We found no card on allergy, pregnancy, children or medicines for either oil, and that absence is a gap in our sources and says nothing about safety.

Sources

1. crsf-daily-r5-02 · food composition dataset
   CoFID 17-033 Oil, corn, per 100 g: Mono FA /100g food 29.90 g; Poly FA /100g food 51.30 g; n-3 poly /100g food 0.90 g; n-6 poly /100g food 50.40 g; Vitamin E 17.24 mg. CoFID 17-045 Oil, sunflower: Mono FA /100g food 20.50 g; Poly FA /100g food 63.30 g; n-3 poly 0.10 g; n-6 poly 63.20 g; Vitamin E 49.22 mg
   CoFID 2021, Public Health England, codes 17-033 and 17-045 (Open Government Licence v3.0) · checked 2026-09-29
2. crsf-daily-r5-01 · food composition dataset
   Corn oil (fdc_id 2710183) per 100 g: Fatty acids, total polyunsaturated 52.9 g; PUFA 18:2 51.9 g; Fatty acids, total monounsaturated 27.7 g; Fatty acids, total saturated 13.4 g; Vitamin E (alpha-tocopherol) 22.6 mg. Sunflower oil (fdc_id 2710192) per 100 g: total polyunsaturated 20.7 g; PUFA 18:2 20.6 g; total monounsaturated 63.4 g; total saturated 8.99 g; Vitamin E 68.48 mg. Corn oil 1 tablespoon 14 g
   USDA FoodData Central survey foods (FNDDS) 2024-10-31, fdc_id 2710183 and 2710192 · checked 2026-09-29
3. crsf-daily-r5-06 · RCT (postprandial)
   Postprandial vascular (FMD and arterial stiffness) responses as well as NEFA and glucose concentrations were comparable between meals. The postprandial TAG increase was lower after heated versus unheated oil (p < 0.001).
   Lipids, 2026 · checked 2026-09-29
4. crsf-daily-r5-04 · 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. Also, in this study, fish oil supplements had a positive and significant effect on HDL (WMD: 2.54 mg/dl, 95% CI: 0.55, 4.52). There were no significant changes in TC and LDL.
   Syst Rev, 2024 · checked 2026-09-29
5. crsf-daily-r5-05 · RCT
   ALA diet lowered serum Lp(a) concentration by 7.3 % (p = 0.003) and LA diet by 9.5 % (p < 0.001) (p = 0.089 for between-diet difference).
   Atherosclerosis, 2024 · checked 2026-09-29
6. crsf-daily-r5-07 · scoping review
   Canola/rapeseed oil may decrease LDL-cholesterol compared to olive oil, sunflower oil and sources of SFA and may also reduce body weight compared to other oils.
   Food Nutr Res, 2024 · checked 2026-09-29
7. crsf-daily-r5-09 · health claim register
   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 2026-09-29
8. crsf-daily-r5-08 · meta-analysis of cohorts
   Also, we found no significant association between dietary intake of LA and risk of total (RR:1.00, 95% CI: 0.97-1.04), advanced (RR: 0.98, 95% CI: 0.90-1.07), and fatal prostate cancer (RR: 0.97, 95% CI: 0.83-1.13).
   Crit Rev Food Sci Nutr, 2024 · checked 2026-09-29