Study Suggests Help for Seniors' Immune Systems

A new study finds that laboratory mice that have a certain enzyme removed from their bodies live 30-60% longer than normal mice. Researchers from the University of Pittsburgh and the Mayo Clinic say that nixing the "PAPPA" protein from the genes of a rodent allowed its thymus to flourish into old age and defend against infections more readily.

The thymus is an organ just above the heart that produces white blood cells. Usually it deteriorates with age and allows the body to be infected more easily; however, lead author Dr. Abbe de Vallejo says he and his colleagues may have found a solution.

De Vallejo says he hasn't found a miracle cure for aging, but his findings could help the elderly. "Extending life is good, but I think the goal is healthy longevity, so not just simply extending life but making sure you have a good quality of life. Obviously a good quality of life would be promoted if you have a good immune system," says de Vallejo. He says there's no telling exactly how much the findings would help humans.

De Vallejo says mice can live up to three and a half years, much longer than their expected two years -- but there are still some unknowns in the process. "They ultimately die, but we dont know what they die of, so one of the things my colleagues and I are doing is trying to ascertain is what the causes of death are," says de Vallejo. The full results of the study will be published in this week's Proceedings of the National Academy of Sciences.