It appears Dracula may have been onto something when he drank the blood of young maidens to stop him aging.
Older people given transfusions of blood from younger adults are at a lower risk of cancer, dementia and heart disease, new research shows.
In groundbreaking trials on humans, scientists appear to have confirmed the long-standing myth that such injections can reverse aging.
Ambrosia, a start-up firm based in San Francisco, has been testing the horror-movie inspired technique to assess its benefits.
It is similar to that of former North Korean dictator Kim Il-Sung who was said to take blood from people in their twenties to try to live to 100.
Jesse Karmazin, founder of the company, told New Scientist: 'I don't want to say the word panacea, but there's something about teenagers.
'Whatever is in young blood is causing changes that appear to make the aging process reverse.'
How did they carry out the study?
The findings came from blood tests that were taken both before and a month after 70 participants were given the radical treatment.
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.
What did they find?
Researchers noted improvements in biomarkers of various major diseases, also known of indicatorsfor 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. Mr Karmazin said that another, slightly older, woman affected worse by the disease is showing similar improvements. He reported some of the firm's findings, which suggested people will receive the most benefit from two injections a year, at the Recode conference in Los Angeles yesterday.
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.
Just last month US research 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.