All it takes to predict an individual's likelihood of developing Alzheimer's disease within the next two to three years is a blood test, according to a study published yesterday in Nature Medicine. The test, New Scientist reports, detects the concentrations of 10 chemicals that are associated with the disease — and the resulting diagnosis is 96 percent accurate.

The secret resides in our fats

In the study, scientists drew blood from 525 healthy adults over the age of 70. Then, they tracked their health for a period of five years. At the end of this period, 28 of the study participants had developed Alzheimer's disease or the cognitive impairments that tend to precede it, so the researchers went back and analyzed the participants' blood to figure out what set these adults apart. As it turns out, the secret to detecting Alzheimer's disease resides in our fats.

The study revealed that people who go on to develop Alzheimer's disease have lower levels of 10 specific lipids in their blood compared with people who stay cognitively healthy. This, the researchers say, could be an indication of the early breakdown of certain populations of neurons in the brain.

The scientists also analyzed the patients' full genome sequence and, according to lead-author and neurologist at Georgetown University Howard Federoff, the genetic changes that took place over the five-year period are an even stronger predictor of future cognitive impairments. That study, however, has yet to be published.

Detection perhaps even 10 to 20 years sooner

The next step in the research is to refine the blood test, Federoff told New Scientist. He would like to determine if the lipid changes can be detected sooner, perhaps even 10 to 20 years sooner. Studies have already shown that early detection is valuable in the treatment of neurodegenerative diseases, so a blood test of this nature could have a considerable impact on drug development.

Of course, without a cure for Alzheimer's disease, the question remains as to whether people will want to make use of these cognitive crystal balls. Many might prefer to remain happily in the dark until the disease hits. But, as Federoff pointed out to New Scientist, there are many other factors to think about besides treatment, or the lack thereof. "We may not have any therapy yet but there are things we can do — we can get our financial and legal affairs in order, plan for future care, and inform family members."