In what could have profound implications for understanding the process of aging, a trio of scientific papers published today show that infusing elderly mice with the blood of young mice can reverse many of the mental and physical impairments of growing old.

Expanding on earlier research, the three studies—published concurrently in Nature Medicine and Science—demonstrate rejuvenating effects in memory, muscle strength, endurance, and sense of smell. Together, they suggest that there might be factors in the young blood that can produce globally regenerating effects in older animals. In addition to reversing the normal ravages of aging, the papers suggest, young blood might help turn around declines in cognitive function associated with age-related conditions such as heart enlargement and Alzheimer's disease.

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