Diet and Liver Diseases

Fatty liver (steatosis) is characterized by an elevated fat content in the liver and is strongly associated with disrupted metabolism and cardiometabolic diseases. Fatty liver, or "Metabolic-dysfunction Associated Steatotic Liver Disease" (MASLD) (previously known as NAFLD), is the starting point for the development of more severe liver diseases, such as cirrhosis and liver cancer. It is also closely linked to type 2 diabetes and cardiovascular diseases. Currently, there are no approved medications for MASLD, emphasizing the significant role of diet in both treatment and prevention.

We have been pioneers in demonstrating that the type of fat plays a significant role in liver fat accumulation. Saturated fats increase, whereas unsaturated fats decrease liver fat, even when the total amount of fat and carbohydrates is the same between groups. In several well-controlled randomized studies, we have shown that saturated fats, whether in the form of palm oil or butter, increase liver fat compared to polyunsaturated omega-6 fats from vegetable oils. The same polyunsaturated fats also improved blood lipid profiles and reduced signs of insulin resistance and inflammation in individuals with abdominal obesity.

We are currently conducting both observational and randomized studies to further investigate the role of diet in both liver fat accumulation and the development of more severe fatty liver.

Key Publications

1. Bjermo H, Iggman D, Kullberg J, Dahlman I, Johansson L, Persson L, et al. Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial. Am J Clin Nutr [Internet]. 2012 May;95(5):1003–12. Available from: http://www.ncbi.nlm.nih.gov/pubmed/22492369
2. Rosqvist F, Iggman D, Kullberg J, Cedernaes J, Johansson H-E, Larsson A, et al. Overfeeding polyunsaturated and saturated fat causes distinct effects on liver and visceral fat accumulation in humans. Diabetes [Internet]. 2014 Jul;63(7):2356–68. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24550191
3. Rosqvist F, Kullberg J, Ståhlman M, Cedernaes J, Heurling K, Johansson H-E, et al. Overeating Saturated Fat Promotes Fatty Liver and Ceramides Compared With Polyunsaturated Fat: A Randomized Trial. J Clin Endocrinol Metab [Internet]. 2019;104(12):6207–19. Available from: http://www.ncbi.nlm.nih.gov/pubmed/31369090
4. Fridén M, Rosqvist F, Kullberg J, Ahlström H, Lind L, Risérus U. Associations between fatty acid composition in serum cholesteryl esters and liver fat, basal fat oxidation, and resting energy expenditure: a population-based study. Am J Clin Nutr 2021;114:1743-1751.
5. Johansson HE, Edholm D, Kullberg J, Rosqvist F, Rudling M, Straniero S, Karlsson FA, Ahlström H, Sundbom M, Risérus U. Energy restriction in obese women suggest linear reduction of hepatic fat content and time-dependent metabolic improvements. Nutr Diabetes 2019;9:34.