Better answers about the origins of dementia and Alzheimer’s disease may be lurking in the bloodstream.

Researchers from The Johns Hopkins University’s Bloomberg School of Public Health have linked unusual levels of 38 proteins in the blood to higher risks of developing Alzheimer’s disease within five years.

Among the proteins researchers evaluated, they found 16 of them were capable of predicting the potential for Alzheimer’s disease two decades ahead of the onset of symptoms.

More than 6 million Americans are affected by Alzheimer’s disease, the most common type of dementia.

In the fight against Alzheimer’s disease researchers focus on two pathologies. One of those is the clumps of protein known as plaques that build up in the brain. The other is tau proteins, which affect communication between brain cells.

The researchers’ analysis of blood samples from 11,000 middle-aged and older people suggest that protein levels in the blood are associated with the potential for developing dementia. Most of the proteins studied were not previously known to be linked to dementia. That, researchers said, raises the prospect that the blood proteins could become new targets to prevent it.

In their analysis, the researchers used a new technology to record the levels of many proteins in the blood. Ultimately, they zeroed in on one that may trigger or drive Alzheimer’s disease.

Next, the group will use the new technology to analyze proteins and blood samples from long-term studies to better focus on therapeutic targets.

In time, the chemical secrets of blood may prove to be a pathway to addressing dementia.