Palm oil and blood sugar markers in people
What it found
In eight short trials in healthy adults, palm oil made little or no difference to fasting glucose, fasting insulin or insulin resistance compared with other vegetable oils.
The authors rate the evidence as poor.
What they found
Studies in people
Fasting glucose
Palm oil made no significant difference to fasting glucose compared with partially hydrogenated soybean oil, soybean oil or olive oil. No significant differences were seen against canola, rapeseed, high oleic sunflower or sunflower oil either.
Fasting insulin
Palm oil made no significant difference to fasting insulin compared with partially hydrogenated soybean oil or olive oil. No significant differences were seen against soybean, canola, rapeseed, high oleic sunflower or sunflower oil.
Insulin resistance
Four studies looked at HOMA, a measure of insulin resistance. Palm oil made no significant difference compared with partially hydrogenated soybean oil, soybean oil, canola oil, sunflower oil, olive oil or high oleic acid sunflower oil.
Post-meal glucose
Only one study measured glucose two hours after a meal. It found no significant difference between palm oil and high oleic sunflower oil.
Other findings
Evidence quality
The authors graded the evidence for fasting glucose as low quality, and for fasting insulin as very low to low quality. They downgraded it because of high risk of bias in the studies, the narrow group of healthy young participants, and wide, non-significant results.
What the authors conclude
“We conclude that little or no additional benefit will be obtained by replacing palm oil with other oils rich in mono or polyunsaturated fatty acids for changes in glucose metabolism.”
Also in their conclusions
- They conclude that current evidence on palm oil and glucose metabolism is poor and limited to healthy participants.
- They say that little or no additional benefit will be obtained by replacing palm oil with other oils rich in mono or polyunsaturated fatty acids for changes in glucose metabolism.
- They recommend more long-term population studies and larger, longer trials that include people with type 2 diabetes, not just healthy participants.
How it was done
Palm oil is the most consumed vegetable oil in many countries, and its high saturated fat content has raised concerns about heart and metabolic health. The authors wanted to see whether palm oil affects blood sugar and insulin differently from other vegetable oils.
They searched three databases up to June 2018 and found eight trials, seven of which were randomised crossover trials and one was a parallel trial. The trials included 333 healthy, non-diabetic, normal-weight adults aged 20 to 40, mostly, and lasted three to seven weeks, with 15% to 20% of energy from fat swapped between palm oil or palm olein and other oils.
What it can’t tell you
- The trials lasted only three to seven weeks, so they cannot show what happens over the long term.
- The participants were healthy, young to middle-aged, normal-weight adults, so the results may not apply to older people, people with diabetes or people with obesity.
- Four crossover trials had no washout period, so results may carry over from one diet to the next.
Who paid
- Conflicts
- The authors have declared that no competing interests exist.
- Authors work at
- Institute for Medical Research, Malaysia
The paper
- Title
- Effects of palm oil consumption on biomarkers of glucose metabolism: A systematic review
- Type
- Systematic review
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Zulkiply SH, Balasubramaniam V, Abu Bakar NA, Abd Rashed A, Ismail SR (2019). Effects of palm oil consumption on biomarkers of glucose metabolism: A systematic review. PloS one. doi:10.1371/journal.pone.0220877Free full textPubMed 31415611DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error