Study Links Sunflower Oil Consumption to Liver Damage in RatsThursday, March 1, 2018
A recent study published in the Journal of Nutritional Biochemistry showed repeated consumption of sunflower oil induced fibrosis, increased oxidative stress and inflammation in the rats’ livers, leaving them vulnerable to non-alcoholic steatohepatitis (NASH). NASH can result from worsening of non-alcoholic fatty liver disease (NAFLD) and can be a precursor to cirrhosis or liver cancer. Sunflower oil contains mainly omega-6 polyunsaturated fatty acids, which have previously been linked to inflammation when consumed in excess.
Different types of fats (sunflower oil, virgin olive oil and fish oil), were fed to rats from weaning until the animals were 24 months old. The impact of the dietary oils on fat accumulation was analysed by the research team from the University of Granada, Spain. The scientists also examined changes over time in liver structure, fibrosis, oxidative stress, gene expression and telomere length (a biomarker of ageing). Results showed liver fat accumulation occurred with ageing, irrespective of the type of oil fed to the rodents. However, other changes to the organ, which took place between the ages of 6 and 24 months, were markedly different according to the type of oil consumed.
“Virgin olive oil led to the lowest oxidation and ultrastructural alterations (to the liver). Sunflower oil induced fibrosis, ultrastructural alterations and high oxidation. Fish oil intensified oxidation associated with age, lowered electron transport chain activity and enhanced the relative telomere length,” observed senior researcher Professor Jose Luis Quiles. Virgin olive oil contains not only a large proportion of monounsaturated fatty acid, but also rich in polyphenols. This contrasts with sunflower oil and fish oil which contain only small or trace amounts of these antioxidant phytonutrients. Previous researches had demonstrated that polyphenols have protection against oxidative stress.