Butter or corn oil: what the swap does to cholesterol

Swapping butter for corn oil lowers LDL cholesterol. A network meta-analysis of 54 randomized trials found that corn oil, along with eight other oils and beef fat, lowered LDL cholesterol by 8.9 to 16 mg/dL (0.23 to 0.42 mmol/l) more than butter. The paper gives one range for all ten fats, with no separate figure for corn oil. The two fats differ sharply on paper. Per 100 g, salted butter has 45.6 g saturated fat and 2.5 g polyunsaturated fat, and corn oil has 13.4 g saturated and 52.9 g polyunsaturated, measured across 13 and 5 USDA samples. A tablespoon of butter gives about 104 calories and 6.4 g saturated fat. A tablespoon of corn oil gives 126 calories and 1.9 g. Butter has fewer calories per spoon because it contains water. Whether lower LDL means fewer heart attacks is less settled.

How much is actually in it

• Salted butter has 45.6 g saturated fat and 2.5 g polyunsaturated fat per 3.5 oz (100 g), while corn oil has 13.4 g saturated and 52.9 g polyunsaturated fat with 22.6 mg vitamin E. — USDA Foundation Foods, 13 butter samples and 5 corn oil samples (n = 18 samples) Evidence E source
  Butter SFA 45.6 g (43.3-48.4); corn oil SFA 13.4 g (13.2-13.6), PUFA 52.9 g (51.9-53.6)

What a real portion looks like

• A tablespoon of butter gives about 104 calories and 6.4 g saturated fat, while a tablespoon of corn oil gives 126 calories, 1.9 g saturated fat and 7.4 g polyunsaturated fat. — US survey food codes, 14 g tablespoon (n = 2 food codes) Evidence E source
  Butter 1 tbsp: 104 calories, SFA 6.4 g, cholesterol 32.9 mg; corn oil 1 tbsp: 126 calories, SFA 1.9 g, PUFA 7.4 g, vitamin E 3.2 mg

What cooking and storage change

• In randomized trials with 10 and 17 volunteers, heated corn oil slowed stomach emptying and cut the next meal by about 600 to 650 kJ compared with unheated corn oil. — healthy volunteers, 10 in experiment 1 and 17 in experiment 2 (n = 27) Evidence B source
  Energy intake about 600-650 kJ lower after heated oil or 2,4-decadienal

What it does to your health

• A network meta-analysis of 54 randomized trials found that corn oil and other plant oils lowered LDL cholesterol by 8.9 to 16 mg/dL (0.23 to 0.42 mmol/l) more than butter, per 10% of energy swapped. — 54 randomized trials of at least 3 weeks comparing oils and solid fats (n = 54 trials) Evidence A source
  LDL-C -16 to -8.9 mg/dL (-0.42 to -0.23 mmol/l) vs butter per 10% isocaloric exchange
• A Cochrane review of 15 randomized trials in about 59,000 people found that cutting saturated fat for at least two years lowered combined cardiovascular events by 21%, with little effect on deaths. — 15 RCTs, about 59,000 adults, at least 24 months (n = 59000) Evidence A source
  CVD events RR 0.79 (0.66 to 0.93); all-cause mortality RR 0.96 (0.90 to 1.03)
• A 2026 meta-analysis of randomized trials in 1690 adults found that diets high in polyunsaturated fat lowered LDL cholesterol by 3.31 mg/dL more than diets high in monounsaturated fat. — 53 records, 1690 adults (n = 1690) Evidence A source
  LDL -3.31 mg/dL (-5.39 to -1.24), TG -6.59 mg/dL, HDL -0.77 mg/dL vs high-MUFA

What people believe that the data does not support

• In the recovered Minnesota trial, a corn oil diet replacing animal fats cut serum cholesterol by 13.8% but showed no mortality benefit, and a meta-analysis of 5 such trials found no clear effect on coronary deaths. — 9423 adults aged 20-97 in Minnesota institutions; 5 RCTs, 10,808 people in the meta-analysis (n = 10808) Evidence A source
  Cholesterol -13.8% vs -1.0%; CHD mortality RR 1.13 (0.83 to 1.54), all-cause 1.07 (0.90 to 1.27)
• The EU rejected a claim that corn oil helps control blood cholesterol, and has authorized no claim for corn oil as such. — EU Register on nutrition and health claims, 1 corn oil entry, 0 authorized Evidence E source
  POL-HC-6985 non-authorized

Who this works differently for

• In a 4-week randomized trial in adults aged 50 to 75, eating 1.8 oz (50 g) of butter daily raised LDL cholesterol by 15 mg/dL (0.38 mmol/L) more than the same amount of olive oil. — 94 healthy men and women aged 50-75, UK, 50 g/day for 4 weeks (n = 94) Evidence B source
  LDL-C +15 mg/dL (6.2 to 23; metric: 0.38 mmol/L, 0.16 to 0.60) vs olive oil, +0.42 vs coconut oil
• In the same Cochrane review, 56 people without heart disease but only 32 people with it would need to cut saturated fat for about four years for one to avoid a cardiovascular event. — primary and secondary prevention trials, about four years (n = 59000) Evidence A source
  NNTB 56 in primary prevention, 32 in secondary prevention

What is still unknown

• The Cochrane review found that data on replacing saturated fat with monounsaturated fat or protein were very limited, so the best swap for butter beyond polyunsaturated oils is not settled. — 15 RCTs, about 59,000 adults (n = 59000) Evidence A source
  No difference between PUFA and carbohydrate replacement; MUFA and protein data very limited

The bottom line

A Cochrane review of 15 randomized trials in about 59,000 people found that cutting saturated fat for at least two years lowered combined cardiovascular events by 21 percent (RR 0.79, 0.66 to 0.93), on moderate quality evidence. It found little or no effect on deaths from any cause (RR 0.96, 0.90 to 1.03). In those trials the saturated fat was replaced by polyunsaturated fat or carbohydrate, and corn oil was not tested by name. Over about four years, 56 people without heart disease would need to make the change for one of them to avoid an event, against 32 people who already had it. The Minnesota trial is the one usually quoted against corn oil. Its recovered data from 1968 to 1973 showed that a corn oil diet replacing animal fats cut serum cholesterol by 13.8 percent against 1.0 percent in controls, with no mortality benefit. A meta-analysis of 5 such trials in 10,808 people found no clear effect on coronary deaths (RR 1.13, 0.83 to 1.54). The trial is criticized for dropout and short exposure, and its control diet included margarines along with animal fats. Events fell in the broader Cochrane set, and deaths did not move in either. In a 4-week trial in 94 healthy adults aged 50 to 75 in the UK, 1.8 oz (50 g) of butter a day raised LDL by 15 mg/dL (0.38 mmol/L) more than the same amount of olive oil. A 2026 meta-analysis in 1690 adults found that diets high in polyunsaturated fat lowered LDL by 3.31 mg/dL more than diets high in monounsaturated fat, a small difference. In two small crossover trials, heated corn oil slowed stomach emptying and cut the next meal by about 600 to 650 kJ compared with unheated oil. That is a short-term effect and says nothing about the long-term safety of frying. The EU did not authorize a claim that corn oil helps control blood cholesterol. Which swap for butter works best beyond polyunsaturated oils is unsettled, because data on monounsaturated fat and protein were very limited. We have no evidence card on allergy, pregnancy or drug interactions for either fat, so this page cannot say who should be careful.

Sources

1. bcor-r1-01 · reference dataset
   FDC 790508 Butter, stick, salted: Fatty acids, total saturated 45.6 g, range 43.3-48.4, n=13 · PUFA 2.52 g · Cholesterol 235 mg · Vitamin A 758 ug RAE · Sodium 524 mg · FDC 748323 Oil, corn: Fatty acids, total saturated 13.4 g, range 13.2-13.6, n=5 · Fatty acids, total polyunsaturated 52.9 g, range 51.9-53.6, n=5 · MUFA 27.7 g · Vitamin E 22.6 mg
   USDA FoodData Central Foundation Foods, release 2026-04-30 · checked 2026-10-02
2. bcor-r1-02 · reference dataset
   FNDDS 2710155 Butter, stick: Energy 743 kcal/100 g, 1 tablespoon 14 g 104.0 kcal, Fatty acids, total saturated 6.4 g, Cholesterol 32.9 mg · FNDDS 2710183 Corn oil: Energy 900 kcal/100 g, 1 tablespoon 14 g 126.0 kcal, Fatty acids, total saturated 1.9 g, Fatty acids, total polyunsaturated 7.4 g, Vitamin E 3.2 mg
   USDA FNDDS 2021-2023 · checked 2026-10-02
3. bcor-r1-09 · randomized crossover trial
   Experiment 2 showed a delayed GE rate in HO and 2,4-DD trials compared with CO trial (p < 0.05). Energy intake was approximately 600-650 kJ lower in HO and 2,4-DD trials compared with CO trial (p < 0.05).
   Nutrients, 2021 · checked 2026-10-02
4. bcor-r1-03 · network meta-analysis
   Safflower, sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, and coconut oil as well beef fat were more effective in reducing LDL-C (-0.42 to -0.23 mmol/l) as compared with butter.
   J Lipid Res, 2018 · checked 2026-10-02
5. bcor-r1-06 · Cochrane review
   The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 21% (risk ratio (RR) 0.79; 95% confidence interval (CI) 0.66 to 0.93, 11 trials, 53,300 participants of whom 8% had a cardiovascular event, I² = 65%, GRADE moderate-quality evidence). ... We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence.
   Cochrane Database Syst Rev, 2020 · checked 2026-10-02
6. bcor-r1-08 · meta-analysis of RCTs
   Fifty-three records were included, representing 1690 adult participants. "High PUFA" diets reduced TC [-5.71 (-8.02, -3.40) mg/dL], LDL cholesterol [-3.31 (-5.39, -1.24) mg/dL], HDL cholesterol [-0.77 (-1.27, -0.26) mg/dL], and TG [-6.59 (-8.77, -4.42) mg/dL] compared with "high MUFA" diets.
   Am J Clin Nutr, 2026 · checked 2026-10-02
7. bcor-r1-05 · meta-analysis of RCTs
   Serum cholesterol lowering diet that replaced saturated fat with linoleic acid (from corn oil and corn oil polyunsaturated margarine). ... The intervention group had significant reduction in serum cholesterol compared with controls (mean change from baseline -13.8%v-1.0%; P<0.001). Kaplan Meier graphs showed no mortality benefit for the intervention group in the full randomized cohort or for any prespecified subgroup. ... In meta-analyses, these cholesterol lowering interventions showed no evidence of benefit on mortality from coronary heart disease (1.13, 0.83 to 1.54) or all cause mortality (1.07, 0.90 to 1.27).
   BMJ, 2016 · checked 2026-10-02
8. bcor-r1-11 · 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 2026-10-02
9. bcor-r1-04 · randomized controlled trial
   LDL-C concentrations were significantly increased on butter compared with coconut oil (+0.42, 95% CI 0.19 to 0.65 mmol/L, P<0.0001) and with olive oil (+0.38, 95% CI 0.16 to 0.60 mmol/L, P<0.0001), with no differences in change of LDL-C in coconut oil compared with olive oil (-0.04, 95% CI -0.27 to 0.19 mmol/L, P=0.74).
   BMJ Open, 2018 · checked 2026-10-02
10. bcor-r1-07 · Cochrane review
    The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 32.
    Cochrane Database Syst Rev, 2020 · checked 2026-10-02
11. bcor-r1-10 · Cochrane review
    Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited.
    Cochrane Database Syst Rev, 2020 · checked 2026-10-02