Growing up poor can have a range of consequences for a person’s status and future opportunities – and it can also make someone more likely to catch colds later in life, a new study shows.
Writing in the journal Brain, Behavior and Immunity, Carnegie Mellon University psychologist Sheldon Cohen and colleagues say they’ve found a connection between childhood poverty and a middle age with more sniffles, coughs and sneezes.
"We have found initial evidence for a biological explanation of the importance of childhood experiences on adult health," Cohen said in a statement. "The association we found in young and midlife adults suggests why those raised by parents of relatively low socioeconomic status may be at increased risk for disease throughout adulthood."
The main culprit seems to be telomeres, which are strings of repetitive DNA at the end of a person’s chromosomes -- kind of like the plastic caps on the end of your shoelaces, but even more important. Telomeres help protect genes from natural degradation, but they get shorter every time your cells divide. Shorter telomeres are thought to play a big role in aging and poor health.
Cohen and the team recruited 152 healthy subjects for their study. To place them on the socioeconomic ladder, the researchers asked participants if they currently owned a home and whether their parents had owned a home during the subject’s childhood. The scientists also drew blood from the subjects to examine the telomeres on their white blood cells. Then, they exposed the participants to the common cold virus, then quarantined them for five days to see if they developed full-fledged symptoms.
Participants who grew up in lower-income homes were both likelier to have caught the cold and to have shorter telomeres. On average, for each year a person’s parents did not own a home during the participant’s childhood, their telomere lengths decreased by 5 percent and their chances of developing a cold after virus exposure were boosted by 9 percent.
"This provides valuable insight into how our childhood environments can influence our adult health," said Cohen.
This latest paper builds off of one of Cohen’s previous studies, published this past February in the Journal of the American Medical Association. In that study, Cohen and colleagues found that telomere length is a good predictor of a person’s ability to fight off colds in young adulthood and middle age. The association starts to hold weight starting at around age 22, but increases throughout life. As a person ages, his or her telomeres get even shorter, thanks to more years of the person's cells dividing.
"Our work suggests the possibility that telomere length is a relatively consistent marker across the life span and that it can start predicting disease susceptibility in young adulthood," Cohen said in February.
SOURCE: Cohen et al. “Childhood socioeconomic status, telomere length, and susceptibility to upper respiratory infection.” Brain, Behavior and Immunity 34: 31-38, November 2013.