FRIDAY, July 3 (HealthDay News) -- Older people in the United States scored better than their counterparts in England on a memory and awareness test, possibly because of differences in levels of depression and education and the fact that American adults receive more aggressive treatment for heart disease, a new study suggests.

The test assessed immediate and delayed recall of 10 common nouns, such as tree, skin, river, table, baby and village. The participants, 13,575 people all older than 65, listened to the words being spoken and then were asked to repeat as many as possible immediately and again five minutes later. During the five-minute wait, the participants were asked other questions.

On a 24-point scale assessing cognitive function, the American seniors scored an average of 12.8 and the English seniors averaged 11.4. That difference represents about 10 years of aging, the researchers said. That means that, on average, 75-year-old U.S. residents had memories as good as 65-year-olds who lived in England.

The findings appear online in the journal BMC Geriatrics.

"Higher levels of education and net worth in the U.S. probably accounted for some of the better cognitive performance," study leader Kenneth Langa of the University of Michigan said in a news release from the journal's publisher. "Furthermore, U.S. adults reported significantly lower levels of depressive symptoms than English adults."

He added that the "better cognitive performance of U.S. adults was actually quite surprising since U.S. adults had a higher prevalence of cardiovascular risk factors, which is generally associated with cognitive decline and poorer mental function."

More aggressive treatment of cardiovascular disease in the United States might help explain the Americans' higher average score, Langa suggested.

More information

The American Psychological Association has more about memory changes in older adults.