It appears Dracula may have been onto something when he drank the blood of young maidens.
Scores of start-ups have been tinkering with transfusions of blood from younger adults to treat age-related diseases.
But a leading geneticist at University College London insists those experiments are no joke, and are seriously considered by leading physicians to be one of the most promising ventures in modern medicine, reports The Daily Mail.
Publishing an analysis of data in the journal Nature, Dame Linda Partridge, a geneticist, says research shows young blood could allow humans to live a life free of diseases like cancer, dementia and heart disease, right up until their deaths.
Her work forms part of a wave of studies and trials, including a set of human trials backed by Peter Thiel at a San Francisco start-up called Ambrosia, injecting older adults with young blood - something that would cost $8,000 if it were rolled out to the public.
Professor Partridge's study showed older mice given young blood did not develop age-related diseases and maintained sharp cognitive function, while younger ones given older blood saw the opposite effect.
It's proof, she says, that blood needs to be more closely studied in animals to identify the molecules that conserve physical health.
"Identification of these is a high priority for research," the study says.
"The practical accessibility of both the human microbiome and blood system makes therapeutic manipulation a particularly attractive approach, but research in animals is needed to establish the long-term consequences and possible side effects."
Professor Partridge and her co-authors Joris Deelen and P. Eline Slagboom add: "[Blood] is the most practically accessible and therefore the most commonly investigated tissue, but it is much less commonly used in animal studies.
"It will be important to develop blood-based biomarkers of risk, ageing hallmarks and responses to candidate interventions in animals."
Theirs is hardly the first study to show such an effect.
The Ambrosia trials involved 70 participants. All of those involved were at least 35 and had paid $8,000 (£6,200) to be part of the experiment out of their own pocket.
They were given plasma - the main component of blood - from volunteers aged between 16 and 25.
Researchers noted improvements in biomarkers of various major diseases, also known of indicators for certain conditions.
This included a 10 per cent reduction in blood cholesterol, of which high levels are known to lead to heart disease.
Other effects noted by the scientists were a 20 per cent reduction in proteins called carcinoembryonic antigens.
These can be seen in high quantities in people who have various forms of cancer, the website reports, but it remains to be seen whether.
The younger blood also helped to slash amyloid protein levels, which forms toxic clumps in the brains of dementia patients, by a fifth.
In particular, one 55-year-old patient with early onset Alzheimer's began to show improvements in his condition after just one transfusion.
Another, slightly older woman with more severe Alzheimer's pathology is showing similar improvements, the start-up reported.
The scientists at Ambrosia envision a world in which elderly people receive two injections a year.
However, he hinted it's possible some of the effects of could have been imagined by those who were desperate to see results after paying so much.
Scientists have long studied the effects of young blood on animals, but have come across a mixed bag of results.
Previous US research has suggested that the blood from human umbilical cords could be the key ingredient for a "fountain of youth" drug.
The Stanford University team discovered a protein found with the plasma can reverse the effects of age-related mental decline.
However, experts at The Ottawa Hospital made a much different finding last July. They noted how blood donations from young women may be linked to poorer survival rates in recipients.