Racial disparities in health among Americans generally has not been understood very well, often because clinical research trials historically didn’t focus on non-white subjects, according to Forbes.

So Kaiser Permanente and the University of California Davis trying to find a way to close at least one racial health knowledge gap to find out why black Americans are more likely than white Americans to develop Alzheimer’s disease. The study will focus on a group of 1,800 racially diverse Kaiser insurance holders over the age of 65 without dementia. Researchers will go back through their medical records from the 1960s through the 1980s to try to find early health markers that could have predicted Alzheimer’s development, and those markers are different for different racial groups.

“Things that happen earlier in life can really have an effect on your brain later in life,” study leader Rachel Whitmer, PhD told Forbes.

The study will take about five years and cost about $13 million, the magazine reported. Check out Forbes to see how else the study could help fill in pieces missing from the understanding of racial health disparities.