American over-65s scored significantly better than their English counterparts at a memory and awareness test. The authors of the research, published in the open access journal BMC Geriatrics, suggest that differences in relative levels of depression, education, and the aggressiveness of treatment for heart disease may be to blame.
Kenneth Langa, from the University of Michigan, led a team of researchers who used data from the U.S. ‘Health and Retirement Study’ and the ‘English Longitudinal Study of Ageing’ to compare the brain health of elderly people from both countries. He said, “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 are generally associated with cognitive decline and poorer mental function.”
Subjects from both countries took tests of immediate and delayed recall of 10 common nouns like hotel, river, tree, skin, gold, village, baby, and table. They heard the words spoken and were asked to repeat as many as possible immediately, then asked other survey questions and were finally asked to repeat the words again five minutes later. During the interview, participants were also asked what day, date, month, and year it was. Taken together, the answers (10 points for immediate recall, 10 for delayed recall, and 4 for orientation) were used to create 24-point scale of cognitive function.
The average score for the 8,299 American participants was 12.8, while the 5,276 English subjects only averaged 11.4 out of 24. This difference approaches the magnitude associated with about 10 years of aging. In other words, 75-year-olds in the U.S. had memories as good, on average, as 65-year-olds in England. According to Langa, “Higher levels of education and net worth in the U.S. probably accounted for some of the better cognitive performance. Furthermore, U.S. adults reported significantly lower levels of depressive symptoms than English adults”.
Transatlantic differences in aggressiveness of cardiovascular disease treatment are also suggested as possible explanations for the English adults’ poor showing.
Source:Biomed Central
