Randomised trial · The American journal of clinical nutrition · 2011Abstract only

Palm olein, olive oil and lard: effects on blood fats

What it found

In 32 healthy men, palm olein raised total and LDL cholesterol more than olive oil did.

It also led to lower blood triglycerides than olive oil.

What they found

Studies in people

Total and LDL cholesterol

Palm olein and lard both raised total cholesterol and LDL cholesterol compared with olive oil. The difference was statistically significant.

Blood triglycerides

Palm olein gave a lower blood triglyceride level than olive oil did. The authors called this unexpected.

HDL cholesterol and markers

There was no difference between the diets in HDL cholesterol, high-sensitivity C-reactive protein, plasminogen activator-1, insulin, or glucose.

What the authors conclude

“The current study did not support the previous finding that the effect of palm olein on total plasma cholesterol and LDL cholesterol in healthy individuals with normal plasma cholesterol concentrations is neutral compared with that of olive oil.”
Tholstrup T, Hjerpsted J, Raff M, 2011

Also in their conclusions

  • They say the study did not support the earlier finding that palm olein has a neutral effect on total and LDL cholesterol in healthy people with normal cholesterol levels, compared with olive oil.
  • They state that the position of palmitic acid in the fat molecule was not confirmed to be important for its effect on blood cholesterol.
  • They describe the lower blood triglycerides after the palm olein diet, compared with olive oil, as unexpected.

How it was done

Palm olein had been reported to have a neutral effect on blood cholesterol compared with olive oil, despite its high palmitic acid content. The authors wanted to test this and the idea that where palmitic acid sits in the fat molecule matters.

32 healthy men took part in a double-blinded, randomised crossover study with three 3-week periods. Each day they replaced part of their usual fat intake with about 17% of energy from palm olein, olive oil, or lard.

What it can’t tell you

  • We summarised it from the abstract only.
  • This was a small study of 32 healthy men, so the results may not apply to women, children, or people with existing health conditions.
  • Each diet period lasted only 3 weeks, so the longer-term effects are not known.

The paper

Title
Palm olein increases plasma cholesterol moderately compared with olive oil in healthy individuals
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Abstract only
Cite
Tholstrup T, Hjerpsted J, Raff M (2011). Palm olein increases plasma cholesterol moderately compared with olive oil in healthy individuals. The American journal of clinical nutrition. doi:10.3945/ajcn.111.018846PubMed 22071711DOI

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