The report, "Valuing the Invaluable, The Economic Value of Family Caregiving" updates a study by AARP last year that estimated that 34 million Americans provide more than 20 hours of care per week to another adult, making informal caregiving a cornerstone of U.S. health and long-term care.

"Family caregivers are a vital and largely unrecognized part of America's health and long-

term care system," John Rother, AARP policy director said in a statement. "We often overlook how much family and friends contribute -- whether it's picking up groceries each week or providing daily healthcare for their loved ones."

Family caregiving has been shown to reduce hospital readmissions and delay entry into nursing homes, reducing the burden on taxpayer-funded Medicare, however, informal caregivers of people age 50 and older spent an average of $5,531 out-of-pocket in 2007 to care for their loved ones, the report said.

Family caregivers also lose workdays, wages, health insurance and retirement savings. More than one-third of informal caregivers are forced to quit their jobs or reduce work hours jeopardizing their own retirement.

Family caregivers also suffer a physical and emotional toll, Rother added.