Alzheimer's is the sixth leading cause of death in the United States and five million people live with the disease every day.

Now there is new hope for early detection.

Researchers at Georgetown University Medical Center say they've developed a blood test that can predict Alzheimer's two to three years before onset.

The study, published this week in the Journal of Nature Medicine, focused on the presence of several fats in the blood of 70-year-old patients.

Researchers say more clinical trials are needed, and right now, a cure is nowhere in sight.

"As a clinician and geriatrician I was excited when I heard about the study. We are getting there but how long it's going to take us who knows," said Dr. Alaa Mira with St. Luke's University Health Network's Center for Positive Aging.

Mira says the possibility of using a blood test to diagnose Alzheimer's before it attacks the brain is hopeful.

Right now, doctors use spinal fluid and MRIs to detect the disease after it manifests.

Mira says a blood test would be a less invasive method that could ultimately change the course of treatment, especially if it were developed to be used in younger people.

"Hopefully with the blood test, new blood test that can identify people that develop the disease and try something before we get there," said Mira.

Mira says if that happens, researchers would have to grapple with the ethical question of telling a younger patient that they have an incurable disease.

But at the same time, he says detecting Alzheimer's decades before it attacks the brain could help unlock a cure.