Latinos and African Americans with Alzheimer’s disease live longer than do whites, Native Americans, and Asians, according to a study published by the journal NEUROLOGY. The findings transcended socioeconomic status, education levels, age when symptoms began, and other factors.

The study followed 31,000 Alzheimer’s patients for an average of 2.4 years and found that Latinos lived an average of 40% longer than whites, while African Americans lived 15% longer than whites. Asian and Native American patients’ longevity was similar to that of whites.

Factors that could account for the differences include the social support of extended families and varying levels of health and other diseases in addition to the Alzheimer’s, according to study author Kala Mehta of the University of California, San Francisco. “Determining the underlying factors behind this difference could lead to longer survival for everyone with Alzheimer’s disease,” says Mehta. “Regardless of the reason for this difference, these findings may have implications for health-care planning for people with Alzheimer’s disease.”