High-oleic sunflower oil as a comparison oil in a supplement trial
What it found
In exercising people, high-oleic sunflower oil was used as the comparison oil for a 12-week supplement trial.
Both groups saw similar drops in some blood fats over that time.
What they found
Studies in people
Blood cholesterol changes
Total cholesterol and LDL cholesterol dropped in both the sunflower oil group and the supplement group over 12 weeks. HDL cholesterol also fell in women across both groups.
Insulin response in women
Women taking the supplement had lower average insulin levels during a sugar test than women taking the sunflower oil. Insulin fell from 24.3 to 20.4 microU/ml in the supplement group but rose from 23.7 to 26.0 microU/ml in the sunflower oil group.
Free fatty acids after sugar
Levels of free fatty acids in the blood after a sugar drink were lower in both men and women who took the supplement compared to those who took the sunflower oil.
Body fat and appetite
Taking the supplement instead of the sunflower oil made no difference to body weight, body fat, resting energy use or feelings of hunger over the 12 weeks.
What the authors conclude
- They conclude that the supplement improved how insulin and free fatty acids responded to sugar in fit, normal-weight women compared to the sunflower oil control.
- They found no specific effects of the supplement on body fat, energy use or appetite when compared to the sunflower oil.
- The authors advise more research to understand why gender, fitness and body fat levels might change how people respond to the supplement.
How it was done
Scientists wanted to test whether a fatty acid supplement changed body fat, energy use and blood sugar handling in fit people. They needed a comparison oil that would not interfere with those measurements, so they chose high-oleic acid sunflower oil.
Sixty-two regularly exercising men and women took either 3.9 g of a fatty acid supplement or 3.9 g of high-oleic acid sunflower oil each day. The trial lasted 12 weeks, and researchers measured body fat, blood fats, blood sugar handling and appetite before and after.
What it can’t tell you
- This trial only looked at fit, normal-weight adults who exercised regularly. It cannot show what happens in people who are overweight or do not exercise.
- The study lasted 12 weeks, so it cannot show what happens if someone takes these oils for years.
Who paid
- Authors work at
- University of Cape Town, South Africa
The paper
- Title
- Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism, glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Lambert EV, Goedecke JH, Bluett K, et al (2007). Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism, glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals. The British journal of nutrition. doi:10.1017/S0007114507172822Free full textPubMed 17381964DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error