3 Findings on Colds You May Have Missed

Three studies published last year provide useful information on risk factors for colds, which affect adults 2 to 3 times a year, according to the US Centers for Disease Control and Prevention.

1. Hugs could buffer the effects of stress on the immune system.

For 14 consecutive evenings, researchers interviewed participants by telephone about conflicts that they experienced and whether they had been hugged that day. The researchers then isolated participants and inoculated them with a common cold virus, monitoring for signs of infection.

They found that a higher percentage of days with hugs was associated with a significantly lower risk for infection. They also found that infection rates increased with greater tension among participants who received fewer hugs.

These results, which were published in Psychological Science, suggest that hugs can buffer the effects of interpersonal stress on the immune system.

2. Fewer hours of sleep are associated with greater risk of infection.

The researchers enrolled 164 healthy volunteers. For 1 week, participants kept diaries and wore wrist devices to measure the quality and duration of their sleep. Researchers then administered rhinovirus-containing nasal drops and monitored subjects for 5 days.

Individuals who slept fewer than 6 hours per night had a significantly greater risk of infection compared with those who had slept for more than 7 hours.

This association remained significant after controlling for pre-challenge antibody levels, demographics, body mass index (BMI), and psychological variables.

Another finding from the Sleep study was that there appeared to be no association between sleep fragmentation and cold susceptibility.

3. Patient’s self-rated health may help determine disease risk for colds.

A study published in Psychosomatic Medicine looked at the relationship between self-rated health and susceptibility to the common cold.

Researchers studied 360 adults aged 18 to 55 years who were generally healthy based on physical examination, laboratory testing, absence of chronic illness, and lack of regular medications.

Questionnaires and interviews were administered to determine the subjects’ self-rated health, socioemotional variables, health behaviors, and experiences of positive emotions. Then, the subjects received rhinovirus via nasal drops.

While 80% of the subjects became infected, only 33% met clinical cold criteria.

The researchers discovered that poorer self-rated health correlated with increased risk of developing a cold after controlling for age, sex, race, BMI, education, income, smoking, drinking, exercise, sleep, parent status, stress, and socioemotional factors. They suggested that self-rated health may be a useful screening tool to measure disease risk.