Butter and olive oil: what the cholesterol trials show

Swapping butter for olive oil has been tested head to head in randomized trials. A network meta-analysis of 54 randomized trials lasting at least three weeks found that olive oil, eight other plant oils and beef fat lowered LDL cholesterol by 8.9 to 16 mg/dL (0.23 to 0.42 mmol/L) more than butter. That range covers the oils as a group, and the abstract gives no separate figure for olive oil. In 94 healthy adults aged 50 to 75 in Cambridgeshire, 50 g of fat a day for four weeks raised LDL by 15 mg/dL (0.38 mmol/L) more on butter than on extra virgin olive oil (95% CI 0.16 to 0.60). Fifty grams a day is a large dose, eaten in ordinary daily life. A double-blind crossover trial in 47 healthy adults found the same direction over five weeks, with no size given in its abstract. One popular belief did not hold up. By a meta-analysis of 51 randomized trials in 4334 adults, olive oil did not significantly change blood glucose, insulin or HbA1c, though results for insulin varied widely between trials.

How much is actually in it

• By the UK composition tables butter is 52.1 g saturated fat and 213 mg cholesterol per 3.5 oz (100 g), while olive oil is 14.3 g saturated and 73 g monounsaturated with no cholesterol. — CoFID 2021 records 17-685 Butter, salted, 17-661 Butter, unsalted and 17-038 Oil, olive, per 3.5 oz (100 g) (n = 3 reference records) Evidence E source
  Butter 744 calories, fat 82.2 g, SFA 52.09 g, MUFA 20.91 g, cholesterol 213 mg, retinol 958 mcg, sodium 730 mg salted vs 8 mg unsalted; olive oil 899 calories, fat 99.9 g, SFA 14.3 g, MUFA 73.0 g, PUFA 8.2 g, vitamin E 5.1 mg

What a real portion looks like

• In the US survey database a tablespoon of butter and of olive oil both weigh 14 g, and a pat of butter for a slice of bread is 7 g. — USDA FNDDS household measures for Butter, stick (81101000) and Olive oil (82104000) (n = 8 and 3 measures) Evidence E source
  Butter 1 tablespoon 14 g, 1 pat 7 g, 1 stick 113 g, per slice of bread 7 g, large sandwich 28 g; olive oil 1 tablespoon 14 g, quantity not specified 14 g

What your body absorbs

• In a crossover RCT of 16 adults, a salad with 28 g olive oil yielded 55.2% more absorbed carotenoids than the same salad with coconut oil. — 16 subjects, carotenoid-rich salad with 0.99 oz (28 g) of olive or coconut oil, emulsified or not, 10-hour plasma curves (n = 16) Evidence B source
  Total carotenoid iAUC +55.2% olive vs coconut oil; alpha-carotene +110.8%, lycopene +45.8%
• Laboratory digestion data suggest beta-carotene was six times less bioaccessible from a high-fat dairy breakfast than when digested with olive oil. — In vitro digestion and Caco-2 cell work following a crossover trial in 7 people (n = 7) Evidence D source
  Beta-carotene bioaccessibility sixfold lower from the dairy-based meal than with olive oil (p < 0.05)

What cooking and storage change

• In a crossover RCT of 20 obese adults, breakfasts made with virgin olive oil heated 20 times reduced NF-kB activation and plasma LPS after the meal. — 20 obese participants, four breakfasts with oils subjected to 20 heating cycles (n = 20) Evidence B source
  Virgin olive oil reduced NF-kB activation and plasma LPS; sunflower oil raised inflammatory gene expression

What it does to your health

• In a 4-week RCT of 94 adults aged 50-75 eating 50 g fat a day, butter raised LDL cholesterol by 15 mg/dL (0.38 mmol/L) more than extra virgin olive oil. — 94 healthy men and women aged 50-75 in Cambridgeshire, UK, 50 g/day of unsalted butter, extra virgin olive oil or coconut oil for 4 weeks (n = 94) Evidence B source
  LDL-C +15 mg/dL (95% CI 6.2 to 23; metric: 0.38 mmol/L, 0.16 to 0.60) butter vs olive oil; no difference in weight, waist or blood pressure
• By a network meta-analysis of 54 RCTs, olive oil and other plant oils lowered LDL cholesterol by 8.9 to 16 mg/dL (0.23 to 0.42 mmol/L) compared with butter. — 54 randomized trials of at least 3 weeks comparing oils and solid fats, per 10% isocaloric exchange (n = 54 trials) Evidence A source
  LDL-C -16 to -8.9 mg/dL (-0.42 to -0.23 mmol/L) for safflower, sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, coconut oil and beef fat vs butter
• In the same 4-week trial, 50 g olive oil a day raised plasma oleic acid by about 1 mol%, while butter raised odd-chain saturated and trans fatty acids. — 96 healthy adults, 50 g/d extra-virgin coconut oil (30), extra-virgin olive oil (33) or unsalted butter (33), 4 weeks (n = 96) Evidence B source
  Olive oil oleic acid +~1 mol%; butter raised odd-chain SFA and trans-FA; changes mostly unrelated to metabolic markers
• Observational data from 221,054 US adults followed up to 33 years link swapping 10 g of butter a day for the same amount of plant oils with 17% lower total mortality. — 221,054 adults in Nurses' Health Study I and II and Health Professionals Follow-up Study, 50,932 deaths (n = 221054) Evidence C source
  Highest vs lowest butter HR 1.15 (1.08 to 1.22); olive oil per 5 g/d HR 0.92 (0.91 to 0.94); substituting 10 g/d butter with plant oils HR 0.83 (0.79 to 0.86)
• Observational data from 60,582 US adults over 28 years link more than half a tablespoon of olive oil a day with 19% lower all-cause mortality. — 60,582 US women and men, 28 years of follow-up, 36,856 deaths (n = 60582) Evidence C source
  All-cause mortality HR 0.81 (0.78 to 0.84); CVD mortality HR 0.81 (0.75 to 0.87)

Safety, limits and interactions

• WHO recommends limiting saturated fat to less than 10% of total energy. — WHO guideline on saturated and trans-fatty acid intake for adults and children, 2023 Evidence E source
  SFA limit below 10% of total energy

What people believe that the data does not support

• By a meta-analysis of 51 RCTs in 4334 adults, olive oil did not change blood glucose, insulin or HbA1c overall. — 51 randomized controlled trials, 4334 adults (n = 4334) Evidence A source
  Glucose WMD -0.04 mg/dL (-0.1 to 0.02); HbA1c WMD 0.02% (-0.01 to 0.06); HOMA-IR improved only at 25-50 g/day
• The USDA 2020 fat review found most butter cohorts reported null links with cardiovascular disease and weighed them less than direct saturated fat data. — Five European cohort articles assessing butter intake, USDA Nutrition Evidence Systematic Review 2020 (n = 5 articles) Evidence C source
  Mostly null associations with CVD, CHD, MI and stroke; one positive for CHD in women
• The EU authorized the claim that olive oil polyphenols contribute to protecting blood lipids from oxidative stress. — EU Register on nutrition and health claims, substance Olive oil polyphenols Evidence E source
  Authorized
• The EU did not authorize the general claim that olive oil promotes heart health. — EU Register on nutrition and health claims, substance Olive Oil Evidence E source
  Non-authorized

Who this works differently for

• In a double-blind crossover RCT of 47 adults, swapping 4.5% of energy to butter for 5 weeks raised total and LDL cholesterol more than refined olive oil. — 47 healthy men and women, mean age 40, 70% women, 2 x 5-week periods, 4.5% of energy from butter or refined olive oil (n = 47) Evidence B source
  Total and LDL cholesterol higher on butter than olive oil (P < 0.05); no difference in triglycerides, hsCRP, glucose or insulin

What is still unknown

• Observational data from 636,151 people show a tablespoon of butter a day was barely linked to mortality (RR 1.01) and not to cardiovascular disease, and no trials existed. — 15 country-specific cohorts, 636,151 participants, 6.5 million person-years (n = 636151) Evidence C source
  Per 14 g/day: all-cause mortality RR 1.01 (1.00 to 1.03); CVD RR 1.00 (0.98 to 1.02); diabetes RR 0.96 (0.93 to 0.99)

The bottom line

Per 100 g in the UK food tables, butter carries 52.1 g of saturated fat and 213 mg of cholesterol. Olive oil carries 14.3 g of saturated fat, 73.0 g of monounsaturated fat and no cholesterol. Butter is about 18 percent water, which is why it has 744 calories per 3.5 oz (100 g) against 899 for olive oil. Salted butter has 730 mg of sodium per 3.5 oz (100 g) and unsalted has 8 mg. A tablespoon of either weighs 14 g in the US survey tables, and the pat of butter on a slice of bread is 7 g. The long term picture comes only from observational data, which show links and cannot show cause. In 221,054 US adults followed for up to 33 years, replacing 10 g of butter a day with the same amount of plant oils was associated with 17 percent lower total mortality (HR 0.83, 95% CI 0.79 to 0.86). That figure is a statistical model built on food questionnaires. In 60,582 US adults over 28 years, more than half a tablespoon of olive oil a day was linked to 19 percent lower all-cause mortality than never or rarely using it (HR 0.81, 0.78 to 0.84). Olive oil users tend to eat a healthier diet overall. Butter on its own shows only a weak signal. Across 636,151 people in cohorts, each tablespoon a day was linked to a 1 percent higher risk of death (RR 1.01, 1.00 to 1.03) and to no change in cardiovascular disease, measured against all other foods rather than against olive oil. That review found no randomized trial of butter on heart attacks or deaths, so this question is still open. A USDA review of five European cohort articles also found mostly null links between butter and cardiovascular disease. The fat you cook with changes what you absorb from vegetables. In a crossover trial in 16 adults, a salad with 0.99 oz (28 g) of olive oil delivered 55.2 percent more carotenoids to the blood than the same salad with coconut oil, and butter was not tested. Laboratory digestion work suggests beta-carotene was six times less available from a dairy-based breakfast than with olive oil. The EU authorized a claim that olive oil polyphenols help protect blood lipids from oxidative stress, a claim about the polyphenols rather than olive oil as a whole. It refused the broader claim that olive oil promotes heart health, which means the evidence fell short when it was assessed. Who should be careful. The authors of the 47-person trial advise people with high cholesterol to keep butter to a minimum. WHO recommends keeping saturated fat below 10 percent of total energy, and butter is about half saturated fat by weight. We have no cards on allergy, pregnancy or medicines for either fat.

Sources

1. btoo-daily-r6-14 · reference dataset
   CoFID 17-685 Butter, salted: Energy 744 kcal, Fat 82.2 g, Satd FA /100g fd 52.09 g, Mono FA /100g food 20.91 g, Poly FA /100g food 2.83 g, Cholesterol 213.2 mg, Sodium 730 mg, Retinol 958 µg, Vitamin E 1.85 mg | CoFID 17-661 Butter, unsalted: Sodium 8 mg | CoFID 17-038 Oil, olive: Energy 899 kcal, Fat 99.9 g, Satd FA /100g fd 14.30 g, Mono FA /100g food 73.00 g, Poly FA /100g food 8.20 g, Cholesterol 0.0 mg, Vitamin E 5.10 mg
   CoFID 2021, Public Health England, records 17-685, 17-661 and 17-038 · checked 2026-10-02
2. btoo-daily-r6-15 · reference dataset
   Butter, stick, FNDDS 81101000: 1 cup 224 g | 1 tablespoon 14 g | 1 stick 113 g | 1 pat 7 g | Guideline amount per slice of bread/roll 7 g | Guideline amount on regular sandwich 14 g | Guideline amount on large sandwich 28 g | Quantity not specified 14 g || Olive oil, FNDDS 82104000: 1 cup 224 g | 1 tablespoon 14 g | Quantity not specified 14 g
   USDA FNDDS, Butter stick 81101000 and Olive oil 82104000 · checked 2026-10-02
3. btoo-daily-r6-09 · RCT
   Similarly, the positive iAUC1-10h of TC, α-carotene, and lycopene were 55.2%, 110.8%, and 45.8%, respectively, higher with olive oil than with coconut oil.
   Am J Clin Nutr, 2023 · checked 2026-10-02
4. btoo-daily-r6-10 · In vitro digestion
   β-carotene bioaccessibility from the dairy-based test meal was sixfold lower (p < 0.05) than when digested with olive oil.
   Eur J Nutr, 2024 · checked 2026-10-02
5. btoo-daily-r6-11 · RCT
   VOO and SOP breakfasts reduced NF-κB activation, increased IκB-α, and decreased LPS plasma concentration.
   Mol Nutr Food Res, 2012 · checked 2026-10-02
6. btoo-daily-r6-01 · RCT
   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
7. btoo-daily-r6-03 · 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
8. btoo-daily-r6-04 · RCT
   Olive oil increased oleic acid (OA) approximately by 1 mol%, while coconut oil and butter had little effect on OA. Butter increased odd-chain SFAs and trans-FAs while olive oil and coconut oil decreased them.
   J Lipid Res, 2024 · checked 2026-10-02
9. btoo-daily-r6-05 · Prospective cohort
   Substituting 10-g/d intake of total butter with an equivalent amount of total plant-based oils was associated with an estimated 17% reduction in total mortality (HR, 0.83; 95% CI, 0.79-0.86; P < .001) and a 17% reduction in cancer mortality (HR, 0.83; 95% CI, 0.76-0.90; P < .001).
   JAMA Intern Med, 2025 · checked 2026-10-02
10. btoo-daily-r6-07 · Prospective cohort
    The multivariable-adjusted pooled HR for all-cause mortality among participants who had the highest consumption of olive oil (>0.5 tablespoon/day or >7 g/d) was 0.81 (95% CI: 0.78-0.84) compared with those who never or rarely consumed olive oil.
    J Am Coll Cardiol, 2022 · checked 2026-10-02
11. btoo-daily-r6-13 · WHO guideline
    The SFA supplied by these amounts of milk and cheddar cheese (67% SFA) would contribute 16.0% of total energy as SFA, far in excess of the WHO recommendation to limit SFA intake to less than 10% of total energy.
    WHO, Saturated fatty acid and trans-fatty acid intake for adults and children: WHO guideline, 2023 · checked 2026-10-02
12. btoo-daily-r6-08 · Meta-analysis of RCTs
    We found the consumption of olive oil was not associated with statistically significant changes in blood glucose (WMD = -0.04 mg dL-1; 95% CI, -0.1 to 0.02; P = .18; I2 = 27.05%), insulin (WMD = -0.3 µIU mL-1; 95% CI, -0.99 to 0.38; P = .39; I2 = 91.49%), hemoglobin A1c (HbA1c) (WMD = 0.02%, 95% CI, -0.01 to 0.06; P = .21; I2 = 0%)
    Nutr Rev, 2026 · checked 2026-10-02
13. btoo-daily-r6-12 · USDA NESR systematic review
    The majority of these articles reported null associations between butter intake and CVD,193,206 CHD and MI,162,176,194,206 or stroke,162,206 with only one article reporting an association between higher butter intake and higher risk of CHD in women, but not in men.162
    USDA NESR, Types of Dietary Fat and Cardiovascular Disease: A Systematic Review, 2020 · checked 2026-10-02
14. btoo-daily-r6-16 · EU claim register
    POL-HC-6431 Olive oil polyphenols Olive oil polyphenols contribute to the protection of blood lipids from oxidative stress Authorised
    EU Register on nutrition and health claims, claim POL-HC-6431, snapshot 2026-09-21 · checked 2026-10-02
15. btoo-daily-r6-17 · EU claim register
    POL-HC-7679 Olive Oil Olive Oil promotes your heart health Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7679, snapshot 2026-09-21 · checked 2026-10-02
16. btoo-daily-r6-02 · RCT
    Butter intake increased total cholesterol and LDL cholesterol more than did olive oil intake (P < 0.05) and the run-in period (P < 0.005 and P < 0.05, respectively) and increased HDL cholesterol compared with the run-in period (P < 0.05). ... We conclude that hypercholesterolemic people should keep their consumption of butter to a minimum, whereas moderate butter intake may be considered part of the diet in the normocholesterolemic population.
    Am J Clin Nutr, 2015 · checked 2026-10-02
17. btoo-daily-r6-06 · Meta-analysis of cohorts
    No RCTs were identified. Butter consumption was weakly associated with all-cause mortality (N = 9 country-specific cohorts; per 14g(1 tablespoon)/day: RR = 1.01, 95%CI = 1.00, 1.03, P = 0.045); was not significantly associated with any cardiovascular disease (N = 4; RR = 1.00, 95%CI = 0.98, 1.02; P = 0.704)
    PLoS One, 2016 · checked 2026-10-02