Researchers in the US have discovered changes in people’s blood that may be able to detect Alzheimer’s disease in its earliest stages. The study, which suggests a possible way to identify people with the disease before symptoms appear, is published in the journal Nature Medicine.
Led by scientists at Georgetown University in Washington DC, the team followed a group of over-70s for five years, none of whom had memory problems at the start of the study. They aimed to discover whether Alzheimer’s could be detected by searching for metabolites – small molecules found in blood and tissue that are by-products of chemical reactions in the body.
Each participant gave blood samples and took part in memory tests once a year. The researchers analysed blood samples from 147 people: 73 who experienced no significant memory decline during the study, 28 who went on to develop either Alzheimer’s or amnestic mild cognitive impairment (aMCI) – memory problems not severe enough to be classified as Alzheimer’s disease – and 46 who were found to have either Alzheimer’s or aMCI at the start of the study.
The results showed there were differences in the metabolites found in the blood of those with Alzheimer’s or aMCI compared to those without memory problems. The researchers found that by looking for changes in 10 different metabolites, they were able to predict with 90% accuracy which people had gone on to develop memory problems. They argue that further investigation is needed to see whether testing for these metabolites may be a useful way of detecting the earliest stages of the disease.
Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, said:
“Alzheimer’s disease begins to develop long before symptoms such as memory loss appear, but detecting the disease at this pre-symptomatic stage has so far proved difficult. More work is needed to confirm these findings, but a blood test to identify people at risk of Alzheimer’s would be a real step forward for research. To test the effectiveness of potential new drugs, it’s important to be able to recruit people to clinical trials in the early stages of the disease, when such treatments are most likely to be effective. If confirmed, these results could also aid efforts to develop better tools for diagnosing Alzheimer’s – allowing people with the disease to access crucial support and existing treatments sooner. We now need to see further studies to investigate the accuracy of this test in larger groups of people.
“These are encouraging findings, but it’s vital to continue investing in research to capitalise on results like these. Half a million people are living with Alzheimer’s in the UK today but we still need better ways to diagnose the disease and treatments that can stop it in its tracks. Research is key if we are to make a real difference to people’s lives.”