Silent vascular disease can affect the way people think, as well as their memory. Now, researchers from the University of California, Davis have discovered that this illness is quite common as people get older.

Charles DeCarli, M.D., one of the investigators involved with the study, said that “we’re beginning to realize that vascular disease plays a major role in Alzheimer’s disease (AD)—they go together.” According to the Centers for Disease Control and Prevention (CDC), about 5 million Americans suffer from AD.

For the study, the researchers wanted to better understand the relationship between white matter hyperintensities, which is damaged brain tissue, and cognitive functioning. More than 800 subjects between the ages of 55 and 90 were followed for two to three years. The participants were either cognitively normal, had mild cognitive impairment or suffered from AD.

The participants who had mild cognitive problems or AD at the beginning of the study had a greater presence of these intensities as the years progressed. Overall, the investigators discovered that as subjects became older, their white matter hyperintensities were linked to faster declines in memory impairment.

Experts suggest that while there is still no cure for AD, there are natural ways to slow the onset of this illness, such as exercising and maintaining a healthy diet.