Rapeseed oil and liver fat in obese men
What it found
In 27 obese men with fatty liver, taking 50 g of rapeseed oil daily for 8 weeks reduced liver fat and free fatty acids in the blood compared with olive oil.
The authors say rapeseed oil may be a useful nutritional option for fatty liver disease.
What they found
Studies in people
Liver fat
Liver fat fell from 13.1% to 11.1% in the rapeseed oil group, while it rose from 13.3% to 15.7% in the olive oil group. The difference between groups at 8 weeks was significant.
Free fatty acids
Blood levels of free fatty acids dropped by 21% in the rapeseed oil group after 8 weeks. No significant change was seen in the olive oil group.
Interleukin-6
Blood levels of interleukin-6 rose 1.68-fold in the rapeseed oil group after 8 weeks. The authors say this rise seems to be liver protective.
Body weight
Body weight, BMI, total body fat and waist-to-hip ratio did not change in either group over the 8 weeks.
Blood sugar and insulin
There were no significant changes in blood glucose, insulin, HOMA IR, or in whole-body and liver insulin sensitivity in either group. Liver enzymes also did not change.
Plasma fatty acids
Rapeseed oil increased plasma alpha-linolenic acid by 1.69-fold at 4 weeks and 1.53-fold at 8 weeks. It also increased linoleic acid. Olive oil slightly increased the n-6/n-3 ratio at 8 weeks.
What the authors conclude
“RA has a beneficial effect on hepatic lipid metabolism as shown by reduced IHL and serum FFA.”
Also in their conclusions
- They conclude that supplementing the diet with rapeseed oil on a daily basis should be considered as a nutritional option for patients with non-alcoholic fatty liver disease.
- They say this is because they found beneficial effects on liver steatosis and serum free fatty acids.
- They call for further studies to uncover the underlying mechanism.
How it was done
Effective treatment for obesity-related fatty liver disease is limited. The authors wanted to find an easy, efficient and low-cost nutritional option for treating liver steatosis.
27 overweight or obese men with fatty liver were randomly assigned to eat a diet with 50 g of refined rapeseed oil or refined olive oil daily for 8 weeks. Liver fat was measured by magnetic resonance spectroscopy, and blood tests and insulin sensitivity tests were done before and after.
What it can’t tell you
- This was a small pilot study with only 27 men, so the results may not apply to women or to larger groups.
- The study lasted only 8 weeks, so it cannot show what happens over a longer time.
- The study cannot show whether the reduction in liver fat would lead to better health outcomes in the long run.
Who paid
- Authors work at
- German Institute of Human Nutrition Potsdam-Rehbruecke, Germany; Charité University Medicine Berlin, Germany; German Center for Diabetes Research (DZD), Germany
The paper
- Title
- Dietary Rapeseed Oil Supplementation Reduces Hepatic Steatosis in Obese Men-A Randomized Controlled Trial
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Kruse M, Kemper M, Gancheva S, et al (2020). Dietary Rapeseed Oil Supplementation Reduces Hepatic Steatosis in Obese Men-A Randomized Controlled Trial. Molecular nutrition & food research. doi:10.1002/mnfr.202000419Free full textPubMed 32920973DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error