A new blood test has been developed that allows scientists to estimate how quickly someone is aging; they hope that it will eventually serve as a predictor of dementia. The test may also be able to determine the “youthfulness” of donated organs for transplant operations. 
The purpose of the test is to determine the “vitality” of certain genes that are indicative of a person’s biological age, versus their chronological age. Researchers say the test can distinguish between healthy patients and those with Alzheimer’s – a promising discovery that may someday help doctors to identify patients who are in the early stages of the disease who have not yet developed symptoms.
The “aging test” could prove to be useful in determining whether donated organs are at risk of failing once they have been transplanted in a patient. If the test shows that an elderly person has a young biological age, it could serve as a way of screening whether that individual might be a good candidate for organ donation.
Researchers analyzed thousands of blood, brain, and muscle samples from people in their 60’s and used them to identify 150 markers of gene activity associated with good health at the age of 65. The scientists then used these biomarkers to develop a score-based rating system for healthy aging that could be assimilated into a blood test.
The team found that a study group of 700 healthy 70-year-olds had wide-ranging healthy aging scores when they were administered the test. Higher scores were associated with better mental ability, kidney function, and longevity over the course of 12 years; low scores were associated with Alzheimer’s. 
“We use birth year, or chronological age, to judge everything from insurance premiums to whether you get a medical procedure or not. Most people accept that all 60-year-olds are not the same, but there has been no reliable test for underlying biological age,” James Timmons, professor of precision medicine at King’s College London, said.
The blood test looks at RNA – an acid associated with genes in different body tissues. Subjects that had been diagnosed with Alzheimer’s were found to have an altered RNA signature in their blood and a lower healthy aging score.
According to Timmons, the test is likely one way of determining which patients are at risk of developing Alzheimer’s, and steering them towards clinical trials for prevention.
The professor explained:
“This is the first blood test of its kind that has shown that the same set of molecules are regulated in both the blood and the brain regions associated with dementia, and it can help contribute to a dementia diagnosis.
This also provides strong evidence that dementia in humans could be called a type of ‘accelerated aging’ or ‘failure to activate the healthy aging program’.”
According to the Alzheimer’s Association, Alzheimer’s disease is the sixth leading cause of death in the United States. One in three seniors die with Alzheimer’s or another form of dementia. This year, the disease is expected to cost the nation $226 billion. That number is expected to rise to $1.1 trillion by 2050.
This article originally appeared at Natural Society.