Nonalcoholic fatty liver disease, characterized by abnormal accumulation of fat within the liver, is associated with childhood obesity.  Nonalcoholic fatty liver disease is associated with insulin resistance, impaired glucose regulation, elevated blood lipids, and increased risk of cardiovascular disease. Recent studies suggest that a dietary imbalance of high omega-6 fatty acids and low omega-3 fatty acids, characteristic of the Western diet, may lead to the development of nonalcoholic fatty liver disease.

A recent study by Nicola Santoro (Yale School of Medicine) and colleagues provides new information about the beneficial effects of a food-based dietary intervention high in omega-3 fatty acids and low in omega-6 fatty acids. In a single-arm unblinded study recently published in The Journal of Nutrition, a total of 17 obese youths between 9 and 19 years of age with nonalcoholic fatty liver were treated with a low omega-6 to omega-3 fat diet for 12 weeks. The ratio of omega 6 to omega 3 fat in the diet was 4:1. The researchers measured changes in hepatic fat and insulin sensitivity. In addition, a common genetic variant in the PNPLA3 gene, associated with development of fatty liver disease in obese adolescents, was also assessed to compare the percentage of changes in liver fat accumulation between homozygous for the high-risk variant and those who carry one or no high-risk variant.

This food-based intervention high in omega-3 fatty acids and low in omega-6 fatty acids reduced fatty liver disease in the majority of participants and restored liver fat content to normal in one-third of the participants, in the absence of weight loss. Furthermore, those with increased risk genotypes tended to have a more robust response to the dietary intervention, suggesting that it may be especially effective in youth with a genetic variant that predisposes to fatty liver disease. Improvements in lipids, lipoprotein concentrations, and insulin sensitivity at the end of the study provides further evidence of a beneficial impact of a diet high in omega-3 fatty acids and low in omega-6 fatty acids. Further studies are needed to determine whether this nutritional modification is generalizable to a large population.

Reference Van Name MA, Savoye M, Chick JM, Galuppo BT, Feldstein AE, Pierpont B, Johnson C, Shabanova V, Ekong U, Valentino PL, Kim G, Caprio S, Santoro N. A low ω-6 to ω-d PUFA Ratio (n-6:n-3 PUFA) Diet to Treat Fatty Liver Disease In Obese Youth. The Journal of Nutrition, Volume 150, Issue 9, 1 September 2020, Pages 2314–2321,

Images credit: