A study published in the prestigious international academic journal GenomeBiology on September 7 reported that a “genetic tag” could predict the onset of certain diseases, such as Alzheimer’s disease, years in advance. Related reading: Getting fat in middle age may lead to earlier onset of Alzheimer’s disease. The study aims to define a set of genes associated with “healthy aging” in 65-year-olds, according to Lin Wei of the Department of Neurosurgery at PLA Hospital 101. Such a molecular profile could be used to identify people at earlier risk for age-related diseases. This could improve the application of real age and complement traditional indicators such as blood pressure. We use year of birth, or actual age, to determine everything from insurance premiums to whether you’ve had a certain medical procedure,” says James Timmons, first author of the paper, from King’s College London, UK. Most people think that 60-year-olds are different, but there has been no reliable test of the underlying ‘biological age. “Our findings, which for the first time provide a powerful molecular marker of human biological age, should transform the way ‘age’ is used to make medical decisions. This includes, among other things, identifying those who are more likely to be at risk for Alzheimer’s disease, as identifying those at ‘early risk’ is key to evaluating potential treatments.” The researchers analyzed RNA from healthy 65-year-olds and used this information to develop a tag containing 150 RNA genes that indicate “healthy aging. They found that when studying RNA from tissues, including human muscle, brain and skin, these tags reliably predicted the risk of age-related diseases. With this RNA tag, they developed a “healthy age gene score” that they used to test and compare RNA frames across individuals and showed that higher scores were associated with better health in both men and women. The researchers studied RNA in healthy people at age 70 and analyzed 20 years of follow-up health data. Although all subjects were born within the same year, their RNA over the 70-year period showed a very wide distribution in the “healthy-for-age gene score,” varying over a four-fold range. This variation was correlated with long-term health. The higher the score, the better the cognitive health and kidney function (across a 12-year span) – both important determinants of mortality. In particular, they demonstrated that patients diagnosed with Alzheimer’s disease had altered “healthy aging” RNA tags in their blood, so that lower healthy age gene scores implied a significant correlation with the disease. Timmons said, “This is the first blood test of its kind to show that the same set of molecules, regulated in the blood and in areas of the brain associated with Alzheimer’s disease, could help contribute to the diagnosis of Alzheimer’s disease. It also provides strong evidence that human Alzheimer’s disease can be termed an ‘artificial aging’ or ‘healthy aging program disorder’.” Given the importance of early intervention in Alzheimer’s disease, it is necessary to identify those at greatest risk for the disease, the authors say, and their “healthy age genetic score” can be integrated to help determine which middle-aged subjects can enter preventive clinical trials and receive clinical treatment many years before the onset of clinical symptoms of Alzheimer’s disease. The authors say their “Healthy Age Genetic Score” could be integrated to help determine which middle-aged subjects could enter preventive clinical trials for clinical treatment of Alzheimer’s disease many years before clinical symptoms appear.