​American researchers claim to have found a way to predict whether a person is at greater risk of developing Alzheimer's disease.

A blood test which it is claimed could be used to predict whether a person is at greater risk of developing dementia has been cautiously welcomed by a UK charity.

Researchers at Georgetown University Medical Center, USA published an article in Nature Medicine journal after they found a set of 10 molecules in blood could be used to predict with 90% accuracy.

Having such a test would be an interesting development, but it also throws up ethical considerations

Dr Doug Brown, director of research and development at the Alzheimer’s Society said the five-year study, which involved only 525 participants, could also give clues on how Alzheimer's disease occurs but it needed larger studies before it could be used as a blood test.

“Having such a test would be an interesting development, but it also throws up ethical considerations,” he said.

“If this does develop in the future people must be given a choice about whether they would want to know, and fully understand the implications.”

Over the course of the study, 28 people who started without cognitive symptoms of the disease went on to develop either mild cognitive impairment or Alzheimer's disease within an average of two to three years.