3 Facts About the Common Cold You May Not Know

The common cold is indeed common, given that its incidence is higher than that of any other human illness.

The common cold is indeed common, given that its incidence is higher than that of any other human illness.

Despite the condition’s prevalence, no one has been able to determine how and why most individuals experience at least 1 cold every year.

A new article published in the Journal of Molecular Biology Research reviewed the following 3 interesting aspects of the common cold.

1. More than 200 virus strains cause the common cold, but the most common are rhinoviruses.

Rhinoviruses seem to capitalize on cooling temperatures, and the longer individuals are exposed to relatively cold temperatures, the more likely they are to contract a cold.

That exposure can be inhaled cold air, body surface cooling, or lowered core body temperature. Even cold feet can increase the likelihood of contracting a cold.

Ambient cooling seems to disturb blood circulation and reduce vessel permeability. Nutrition at the tissue level deteriorates and resistance to infectious agents declines, which opens the door for viral infection.

2. Children are much more likely to contract colds than adults.

Most researchers believe that this has to do with children’s high body heat conductivity and immature immune systems. Children are also more sensitive to drops in temperature than older adults.

In addition, men are more likely than women to develop the sniffles, and men seem to suffer more from colds regardless of age. Some theorists believe that this is because men’s body heat conductivity is higher than women’s, or that women’s resistance may be tied to their reproductive role. Biologically, women may have evolved resistance mechanisms to protect their young.

3. Only humans and apes can catch colds.

Some theorists believe that this is because these 2 species are unique in that they cannot make their own ascorbic acid. Some also suggest that certain primates have enhanced body heat conductivity that contributes to fast, deep cooling of their bodies when they are exposed to cold temperatures.

The review author also added a new theory to the mix. He discussed 2 types of genetic material: heterochromatin, the genome’s variable portion that is predominantly non-coding repeated DNA sequences, and euchromatin, the genome’s conservative portion that contains transcribed structural genes. All eukaryotes—plants, animals, and humans—have heterochromatin.

The inherited heterochromatin regions account for about 15% to 20% of the human genome, and the 2 types are Q- and C-heterochromatin.

All higher eukaryotes have C-heterochromatin, but only humans, chimpanzees, and gorillas have Q-heterochromatin. Gorillas and chimpanzees seem to have the greatest number of Q-heterochromatin regions, while humans have the least.

Here are a few things to know about an individual’s quantity of chromosomal Q-heterochromatin:

· Q-heterochromatin seems to be determined by the ecological environment, rather than racial or ethnic traits.

· Those who live in southern geographical latitudes have more Q-heterochromatin, while those in northern latitudes have less.

· Women have less Q-heterochromatin than men, and children have more Q-heterochromatin than older adults.

· Those who readily adapt to extreme high-altitude climates and the farthest and coldest latitudes usually have extremely small quantities of Q-heterochromatin.

Thus, the pattern of Q-heterochromatin distribution is similar to the patterns we see with the common cold. Q-heterochromatin has also been linked to human body heat conductivity.

Since chromosomal heterochromatin remains constant in ontogenesis, body heat conductivity—as well as the propensity to contract the common cold—may be constitutional characters like skin color, eye shape, body constitution, height, and other innate physical human traits. This is simply a hypothesis at this time, and the fact that monkeys do not contract the common cold is a confounder.

If body heat conductivity is inherited and a risk factor for cold, teaching at-risk patients to stay warm may reduce the incidence of the common cold.