High-fructose corn syrup intake increases hepatic mitochondrial DNA copy number and methylation in adolescent rats

High-fructose corn syrup (HFCS) is consumed worldwide. However, it has been demonstrated that an increased intake of sweetened beverages, including those sweetened using fructose, is associated with the development of childhood obesity. It is unknown why the negative effects of fructose are stronger in young persons than in elderly individuals. In recent years, mitochondria have been identified as 1 of the targets of the negative effects of fructose; they possess their own genome called mitochondrial DNA (mtDNA), which encodes genes involved in metabolic functions. We hypothesized that HFCS intake affects mtDNA in the livers of rats, and that the intensity of these effects is age-dependent. The experimental period was divided into 3 parts: childhood and adolescence (postnatal day [PD] 21-60), young adulthood (PD61-100), and adulthood (PD101-140). Rats in the different age groups were assigned to receive either water (control group [CONT]) or a 20% HFCS solution (HFCS). The hepatic mtDNA copy number of the HFCS group was higher than that of the CONT group in childhood and adolescence. In addition, the mtDNA methylation level