After the blood was put into the circulatory system of the older mice, they were found to have dramatic improvements in brain and muscle strength and activity. The mice given younger blood were also able to last longer on a treadmill than the control group, which was given saline. Young mice injected with old blood saw a negative effect of premature aging.
The findings are the result of three studies, all published Sunday in the journals Science and Nature Medicine, with two by Harvard Stem Cell Institute and one by a group of researchers from Stanford University.
The researchers are trying to narrow down what in the blood of the young mice causes the effects, and found that a prevalent protein in the young blood, GDF11, caused the same effects when injected to the older mice. The researchers believe there are other components in the blood that help reverse aging but this protein is one of the main components.
The hope is the new studies will lead to human tests, and possible treatments for dementia and Alzheimer's.
"Right now we can’t do anything for Alzheimer’s patients, and this seems so easy and simple," said Tony Wyss-Coray, a neuroscientist and study author from Stanford University.
Beyond the mental effects of aging, scientists are hoping to find that with greater knowledge of the aging process, they can start to tackle other diseases that come with getting older.
"If we understand the aging process in enough detail, we can begin to tackle the underlying mechanisms rather than treating one disease at a time," said Judith Campisi, a biochemist at the Buck Institute for Research on Aging.