Randomised trial · Journal of lipid research · 2024Conflicts declared

Coconut oil, olive oil and butter change blood fatty acids

What it found

In 96 healthy middle-aged adults, four weeks of eating 50 g a day of coconut oil, olive oil or butter changed the mix of fatty acids in the blood in different ways.

Coconut oil doubled two saturated fats in the blood, while olive oil raised oleic acid.

What they found

Studies in people

Coconut oil fatty acids

Coconut oil doubled the blood levels of lauric acid and myristic acid. Butter increased these to a lesser extent, and olive oil reduced them.

Olive oil and oleic acid

Olive oil increased oleic acid in the blood by about 1 mol%. Coconut oil and butter had little effect on oleic acid.

Butter and trans fats

Butter increased odd-chain saturated fats and trans fats in the blood. Olive oil and coconut oil decreased them.

Metabolic markers

Changes in most fatty acids showed no significant links with changes in metabolic markers like cholesterol. The authors found no strong evidence that coconut oil's lauric and myristic acids were linked to harmful changes in LDL, HDL or total cholesterol.

What the authors conclude

“In conclusion, the current findings suggest that in healthy middle-aged adults, the consumption of equal amounts of coconut oil, olive oil or butter leads to differential changes in plasma FAs, largely driven by differences in the predominant FAs in these dietary fats.”
Sowah SA, Koulman A, Sharp SJ, Imamura F, Khaw KT, Forouhi NG, 2024

Also in their conclusions

  • They conclude that equal amounts of coconut oil, olive oil or butter lead to different changes in blood fatty acids, mostly due to their different fatty acid contents.
  • They note a marked difference between coconut oil and butter on individual blood fatty acids, even though both are major sources of saturated fat.
  • They call for further studies to confirm these findings and to look at long-term effects on heart and metabolic disease risk.

How it was done

Dietary guidelines recommend limiting saturated fat, but there is growing interest in whether all saturated fats have similar metabolic effects. The authors wanted to compare how common dietary fats affect individual fatty acids in the blood.

They studied 96 healthy adults aged 50 to 75 in Cambridge, UK, for four weeks. Participants were randomly assigned to eat 50 g a day of extra-virgin coconut oil, extra-virgin olive oil, or unsalted butter, and blood fatty acids were measured at the start and end.

What it can’t tell you

  • This was a four-week study, so it cannot show what happens over a longer time.
  • The study measured fatty acids in the blood, not heart disease or diabetes outcomes.
  • The dose was fixed at 50 g a day, so it cannot show what different amounts would do.

The paper

Title
Effects of coconut oil, olive oil, and butter on plasma fatty acids and metabolic risk factors: a randomized trial
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Sowah SA, Koulman A, Sharp SJ, Imamura F, Khaw KT, Forouhi NG (2024). Effects of coconut oil, olive oil, and butter on plasma fatty acids and metabolic risk factors: a randomized trial. Journal of lipid research. doi:10.1016/j.jlr.2024.100681Free full textPubMed 39490924DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error