Researcher links class status with flu susceptibility

Credit: Michael Setzer/SciTech Editor Credit: Michael Setzer/SciTech Editor

You don’t decide the circumstances of your birth, such as who your parents are, where you live, or your family’s financial status. But according to the ongoing research of Sheldon Cohen, a professor of psychology at Carnegie Mellon, these uncontrollable factors greatly influence health and wellness.

Since 2004, Cohen has attempted to find a causal relationship between lower socioeconomic status and health. Studying subjects in the Pittsburgh area, his research group mapped the socioeconomic backgrounds of its volunteers and then exposed them to the common cold to find their susceptibility.

“There was a very linear relationship between the number of years in a lower socioeconomic status and whether they got sick: the more years without a home, the more likely to respond to the virus,” Cohen said.

In psychological studies, home ownership is widely used as a marker for socioeconomic status. “It is considered a marker of income, wealth, and social status,” Cohen said.

However, the results from the first study revealed that not just people in extreme poverty feel the effects. Cohen said, “It turns out that the association follows a gradient. The risk gradually decreases with more and more years with home ownership.”

With these results in hand, it was clear that the relationship between poverty and health was not so black and white.

Cohen sought after other explanations, looking at common habits associated with low living standards such as increased alcohol consumption, smoking, and lack of exercise. However, none of these standards were able to prove the experimental results.

Last week, Cohen published groundbreaking research that could potentially solve this conundrum. He found a biological link between a lower socioeconomic status during childhood and a higher susceptibility to catching the common cold. According to his research, this relationship can be explained through telomeres.

Telomeres are essentially shields placed on the ends of DNA that protects it from degrading every time the cell replicates. However, telomeres slowly decrease in size over time; when they are no longer able to do their job, the cell is unable to replicate and dies.

In 2004, Cohen published research suggesting that a lower socioeconomic status in childhood could indicate a weaker resistance to infection. Consequently, Cohen said his latest research was driven by two fundamental questions: “Can we replicate the previous findings we had in 2004, and can we explain them through telomere length?” His research group was able to accomplish both goals.

Not only did the study uphold the strong correlation between childhood living standards and the likelihood of receiving an infection, but it also found that volunteers with lower socioeconomic status consistently had shorter telomeres.

“This doesn’t mean there is a direct causal relationship. However, the data is consistent. Statistically, 25 percent of susceptibility to the cold can be attributed to telomere length,” Cohen said.

He also mentioned that one factor that holds a strong correlation with shortened telomeres is stress. This is one possible explanation for his results, because people growing up in unstable living situations are likely to experience much more stress in their early years.

Moving forward, Cohen is going to continue this line of research. His lab is beginning a large project that will determine whether or not a lower socioeconomic status causes a faster rate of telomere degradation. This study will be conducted with over 1,500 volunteers. Fifteen years ago, Cohen recorded the social and economic backgrounds of these individuals and extracted samples of their blood. He will now go back to the volunteers and take down the same recordings. He hypothesizes that the subjects from a lower social status have a higher telomere degradation rate.

Cohen believes his research is providing vital information on how living standards can have a direct biological impact on humans. While it has always been clear that it is important to allocate resources toward bringing people out of poverty, this research may suggest that it should not be just a goal, but a priority.