If you’ve ever wondered why it seems like some people get a cold every month, don’t assume they’re just weaklings. New research suggests that the reason certain people get sick more often is in their genes.
A study published this week in the Journal of the American Medical Association has identified a biological marker in the immune system that predicts one’s ability to fight off the common cold. The catch? It doesn’t start predicting until about age 22.
Researchers at Carnegie Mellon in Pittsburgh determined that the length of telomeres, protein caps at the ends of chromosomes, predict resistance to upper respiratory infections in adults beginning in early adulthood. Measuring telomere length is already used as a biological marker of aging. Research shows that older people with short telomeres are more likely to die at an earlier age, and are at greater risk for immune-related diseases, such as heart disease and cancer.
For the study, the research team exposed 152 healthy volunteers aged 18 to 55 to rhinovirus, which causes the common cold. Then, they were quarantined for five days.
Results showed that the telomere lengths of participants between 18 and 21 did not predict their likelihoods of developing colds. Instead, researchers found that the older the participant, the telomere length became an even stronger predictor of risk of infection. Those with short telomeres were more likely to catch a cold than those with long telomeres.
“Beyond what we already knew about [. . .] telomere length being a risk for illness and mortality among older people, this [research] suggests it may actually start being at risk very early on in young adulthood,” lead researcher Sheldon Cohen said in a video statement.
The full study is available at JAMA’s website.
