December 11, 2012
Childhood Adversity May Slow Cognitive Decline In Later Years
April Flowers for redOrbit.com - Your Universe Online
A new study from the Rush Alzheimer's Disease Center at Rush University Medical Center suggests that people who experienced adversity as children, such as sometimes going hungry, may have slower cognitive decline in their elderly years compared to people who had easy childhoods.
"These results were unexpected because other studies have shown that people who experience adversity as children are more likely to have problems such as heart disease, mental illness and even lower cognitive functioning than people whose childhoods are free of adversity," said Dr. Lisa L. Barnes, associate professor in the departments of Neurological Sciences and Behavioral Sciences at Rush University. Dr. Barnes is also a cognitive neuropsychologist at the Alzheimer's Disease Center at Rush University Medical Center.
The participants in the study were 6,158 Chicago residents with an average age of 75, and 62 were African-American. Participants were asked about their health as children, the financial situation of their family, and their home learning environment — how often others read to them, told them stories and played games with them. After the initial assessment, the participants were given cognitive tests to measure changes every three years for up to 16 years.
The study, published in the journal Neurology, found that the 5.8 percent of the African-American participants who reported sometimes or often going without enough food to eat as children were more likely to show a slower rate of cognitive decline. The decline was reduced by about one-third compared to those who rarely or never went without enough food. Another subset of the participants with slower cognitive decline — again by one-third — were the 8.4 percent of African Americans who reported being much thinner at age 12 than their counterparts.
Interestingly, the researchers found no relationship between childhood adversity factors and cognitive decline for Caucasian participants.
"Researchers are not sure why childhood hunger could have a possible protective effect on cognitive decline," said Barnes. "One potential explanation for the finding could be found in research that has shown that calorie restriction can delay the onset of age-related changes in the body and increase the life span."
Dr. Barnes suggests a selective survival effect as another explanation.
"The older people in the study who experienced childhood adversity may be the hardiest and most resilient of their era; those with the most extreme adversity may have died before they reached old age," said Barnes.
Even after adjusting the results for factors such as education level and health problems, the researchers found that the patterns remained. The research team also found the same results after excluding people with the lowest cognitive function at the beginning of the study. This was to rule out the possibility that people with mild, undiagnosed Alzheimer's disease might be included in the study.
"Because relatively few Caucasians in the study reported childhood adversity, the study may not have been able to detect an effect of adversity on cognitive decline in Caucasians," Barnes said.