Older adults who faced social and economic hardships in childhood are more likely to score lower on tests of cognition, according to a new international study published online in the journal Neurology.
“Just like the body, the brain ages, but for some it may age faster than others,” said study author Pavla Cermáková, M.D., Ph.D., of the Czech National Institute of Mental Health in Klecany, Czech Republic.
“A growing body of evidence suggests aging of the brain may occur over a lifetime with its roots in childhood. Our study looked at a very large number of people from different backgrounds and geographic locations and found that social and economic disadvantages in childhood may indeed have a negative impact on cognitive skills.”
For the study, researchers looked at the data of 20,244 people (average age 71 at start of study) from 16 European countries who were part of a larger study called the Survey on Health, Ageing and Retirement in Europe. Participants were interviewed and tested once and then again at least one more time an average of five years later.
Participants completed tests of cognition that measured verbal and memory skills, including learning new words and recalling them after a delay.
To determine socioeconomic hardship in childhood, participants were asked questions about their home life situation at age 10, using a method known as a “life history calendar,” a technique used to improve the accuracy of recalled information.
Participants were asked about the number of rooms in the home, the number of people living there as well as the number of books. Researchers calculated a ratio for the number of people in the home to the number of rooms and considered those individuals with the highest ratio and the lowest number of books as those having experienced socioeconomic hardship.
A total of 844 people, or 4 percent of the entire group, experienced socioeconomic hardship in childhood. The findings show that these participants scored lower in the cognitive tests. They were also less educated, less employed and less frequently living with a partner in the home. They also scored higher in symptoms of depression, were less physically active and in general less healthy.
At the beginning of the study, cognitive test scores for all participants ranged anywhere from -2.39 to 3.45. Negative scores represent a lower level of cognitive performance.
After adjusting for age, sex and geographic location, researchers found those who experienced socioeconomic hardship in childhood performed lower on the cognitive tests than the rest of the group by an average of .27 points.
Even after taking into account differences in social and clinical factors such as education, employment, depression, body mass index, physical activity and cardiovascular diseases, they still scored an average .15 points lower.
While researchers found a difference between the two groups in cognitive skills, they found no link between socioeconomic hardship in childhood and a decline in these skills over time.
“While our research is observational, and cause and effect cannot be determined, it is by far the largest group of people ever studied on this topic,” said Cermáková.
“Our study shows that the environment where we grew up is mirrored in the level of our cognitive skills when we are old; and this is only partly explained by education, depression or different life style factors.”
“However, the childhood socioeconomic environment no longer affects how we fight against the declining skills while we age. We believe that the focus of strategies aiming to protect cognitive health should be shifted into childhood, taking into account that children facing social and economic challenges should be provided with more resources to counter the disadvantages they face.”
A limitation of the study is that participants had to recall information from childhood and memories may not always be accurate. Also, those who face hardship in childhood also face a higher risk of death, so healthier people may have been overrepresented in this study.
Source: American Academy of Neurology