It's childhood experiences that affect your risk of cognitive impairement later in life, according to a new study, and not race.

Prior studies have linked race and ethnicity to an increased risk of late-life cognitive impairment, such as dementia. The new study, however, focuses on the effects of a person's childhood, as well as their socioeconomic status and literacy, on cognitive impairment later on. "These findings are important, because it challenges earlier research that suggests associations between race and ethnicity, particularly among Latinos, and an increased risk of late-life cognitive impairment and dementia," said lead author of the study Paul Brewster, a doctoral student at the University of Victoria, Canada, in a press release

For the study, 300 participants, aged 60 and older, were recruited from various senior settings, including a social, recreational, and residential center. The men and women spoke English or Spanish, had no major psychiatric illnesses or life threatening medical illnesses, and were Caucasian, African-American, or Hispanic. All participants were evaluated using multidisciplinary diagnostic evaluations through the UC Davis Alzheimer's Disease Center in Spanish or English.

The researchers found that non-Latino Caucasians scored 20 to 25 percent higher on semantic memory tests (memory of meanings, understandings, and concept-based knowledge), and 13 to 14 percent higher on tests of executive function compared to other ethnic groups. One of their greatest findings, however, was that differences in semantic memory dropped by 20 to 30 percent, and ethnic differences in executive function disappeared when socioeconomic status, literacy, and levels of physical activity during their lives were considered. 

"It shows that variables like ethnicity and years of education that influence cognitive test scores in a single evaluation are not associated with rate of cognitive decline, but that specific life experiences like level of reading attainment and intellectually stimulating activities are predictive of the rate of late-life cognitive decline. This suggests that intellectual stimulation throughout the life span can reduce cognitive decline in old age," said Dan Mungas, professor of neurology, in the release.

Alzheimer's is a growing health concern among the elderly. It is the most common form of dementia and the sixth leading cause of death in the United States. Currently, 5.3 million Americans are affected by Alzheimer's, according to the Centers for Disease Control and Prevention. By 2050, those numbers are expected to double. This research is critical in understanding dementia and can assist in finding new treatments for Alzheimer's.

Source: Brewster PW, Melrose RJ, Marquine MJ, et al. Life Experience and Demographic Influences on Cognitive Function in Older Adults. Neuropsychology. 2014.