In a first-of-its-kind study from the University of Rochester Medical Center, researchers have developed a blood test for Alzheimer’s disease that accurately predicts whether a healthy person will develop the disease.

It is hoped the test will someday be available in doctors’ offices, since the only methods for predicting Alzheimer’s right now, such as PET scans and spinal taps, are expensive, impractical, often unreliable and sometimes risky.

“This is a potential game-changer,” said Dr. Howard Federoff, senior author of the report and a neurologist at Georgetown University Medical Center. “My level of enthusiasm is very high.”

Mark Mapstone, a neuropsychologist and lead author of the study says the beauty of this test is that it caught Alzheimer’s before the patient even had symptoms, suggesting that the disease process begins long before people’s memories start failing. He says that perhaps the lipid levels started decreasing at the same time as brain cells started dying.

Researchers drew blood from hundreds of healthy people over age 70 living near Rochester, New York, and Irvine, California. Five years later, 28 of the seniors had developed Alzheimer’s disease or the mild cognitive problems that usually precede it. Looking at more than 100 fats, or lipids, for what might set this group apart, they found that these 28 seniors had low levels of 10 particular lipids, compared with healthy seniors.

To confirm their findings, the researchers then looked at the blood of 54 other patients who had Alzheimer’s or mild cognitive impairment. This group also had low levels of the lipids.

Overall, the blood test predicted who would get Alzheimer’s or mild cognitive impairment with over 90% accuracy.

He and his team plan to try out this test in people in their 40s and 50s. If that works, he says, that would be the “holy grail,” because then researchers could try experimental drugs and treatments in a group that’s almost sure to get the disease. That would speed research along immensely.

Plus, people could get a heads up that they were probably destined to get Alzheimer’s. Although some people might not want to know that they’re destined for a horrible disease, others might be grateful for the warning.