Young Blood May Contain Chemical Factors Which Can Prevent or Reduce Some Effects of Aging
It seems like a horror story hearkening back to legends of the “Blood Countess” Elizabeth Bathory, who reportedly bathed in the blood of slain maidens to keep her youthful complexion, but rumors persist that late North Korean dictator Kim Jong Il would inject himself with the blood of young people (presumably donated blood from still-living donors) to slow his aging process.
Surprisingly, scientists have found hints that Countess Bathory and Kim Jong Il may have been onto something. Researcher Saul Villeda of Stanford University presented a study done on mice to the annual meeting of the Society for Neuroscience in New Orleans. His results indicate that an older mouse injected with the blood of a younger mouse shows a reversal of some signs of aging. In fact, the older mice who received the treatment showed greater cognitive and memory abilities than did untreated mice of similar age.
Villeda's research involved connecting the circulatory systems of two mice by a technique known as heterochronic parabiosis, which is typically used to study immune systems. After the blood of the old mice and young mice had mixed, Villeda found that the older mice showed distinct signs of a slowdown or even a small reversal in the aging process. The brains showed an increase in stem cells, and the connections between neurons had increased by 20%. "One of the main things that changes with ageing are these connections, there are a lot less of them as we get older," Villeda explained. "If you have less connections, neurons aren't communicating, all of a sudden you have [problems] in learning and memory."
This new study, not yet published in a peer-reviewed journal, is a follow-up to a study Villeda and his colleagues published last year in Nature. The earlier study showed that young mice exposed to old blood showed brain deterioration, and old mice exposed to young blood showed an increased stem cell count. In the new study, Villeda and his team also tested the mice’s behavior.
Villeda injected small amounts of blood plasma, the liquid portion of blood, from two-month-old mice into 18-month-old mice eight times over the course of a month. The amount of plasma used was approximately 5% of a mouse’s total blood volume. Villeda then had the mice solve a water maze, an activity in which mice have to remember the location of a platform. Untreated older mice made mistakes as they attempted to solve the maze, such as swimming down blind alleys. Mice who had received the young plasma, however, often found the platform on their first try and performed similarly to mice four to six months of age.
Villeda thinks the plasma may have helped improve the older mice’s brain power by replenishing chemical factors which decrease during normal aging. "All of a sudden you have all of these plasticity and learning and memory-related genes that are coming back,” he said.
Much more research will be required before these findings can help develop an effective anti-aging treatment for humans, particularly because blood contains thousands of chemical factors and researchers were unsure of which ones helped rejuvenate the older mice. Villeda, however, believes that treatments based on factors found in youthful blood may eventually be able to help middle-aged people prevent some of the worst effects of age-related deterioration, possibly even Alzheimer's disease.
Andrew Randall, a professor of applied neurophysiology at Exeter and Bristol Universities, thinks these findings show potential for future treatments. “Temporarily plumbing teenagers' blood supplies into those of their great-grandparents does not seem a particularly feasible future therapy for cognitive decline in aging,” he said. “Instead this fascinating work suggests there may be significant benefit in working out what the 'good stuff' is in the high octane young blood, so that we can provide just those key components to the elderly."
University College London professor of regenerative medicine bioprocessing Chris Mason agrees. "Even if the finding leads only to a drug that prevents, rather than reverses the normal effects of ageing on the brain, the impact upon future generations will be substantial – potentially outweighing other wonder drugs such as penicillin."
Villeda says the results of his research have changed his opinion on how anti-aging treatments might be developed. "Do I think that giving young blood could have an effect on a human? I'm thinking more and more that it might," he said. "I did not, for sure, three years ago."