New research shows student debt has reached a record high in the United States, with nearly one in five households now burdened by debt from college loans. According to the Pew Research Center, the number of households with college debt doubled from 1989 to 2010 and jumped 15 percent over just three years from 2007 to 2010. Researchers found the poor are most heavily burdened by college debt, with student loans consuming nearly a quarter of household income for the poorest 20 percent of Americans.