The fructose–copper connection: Added sugars induce fatty liver and insulin resistance via copper deficiency

Background:  Evidence suggests that the overconsumption of added sugars can induce fatty liver disease and insulin resistance. Aim:  To propose a hypothesis that added sugars induce copper deficiency which can lead to hepatic iron overload, fatty liver disease, insulin resistance and eventually non-alcoholic steatohepatitis. Setting:  On average, the intake of added sugars in humans is higher than levels that have been found to impair copper status in animals. Methods:  Narrative review. Results:  Fructose-induced copper deficiency may be a leading cause of fatty liver disease and insulin resistance. Conclusion:  The reduction in the intake of added sugars may improve copper status and reduce the risk of fatty liver disease and insulin resistance.