For years researchers have been trying to find ways to prevent and treat the common cold. Given the wide array of common respiratory viruses and the way we live modern life, however, complete prevention is not practical.
Preventing a virus from infecting a young child or an infant is a particular challenge; their immune systems are new and they are surrounded by germs. Here I will share a few observations on how the little ones get sick, how they share what they catch, and what parents can do to protect the whole family.
Young children who go to nursery school or other indoor play centers typically contract 8 to 12 respiratory illnesses per year. Most of the colds, fortunately, will be limited to the upper airway. How sick a child becomes each time is determined by factors such as age, nutritional reserve, and immune resilience. Some common viruses, such as respiratory syncytial virus, cause cellular injury to the lower respiratory tract lining in infants. Influenza weakens local tissue defenses, allowing increased adhesion to respiratory epithelial cells of pathogenic bacteria such as pneumococci.
Magnitude of exposure is key
The size of the viral “inoculum” also plays a role. The greater the exposure, the sicker the child is likely to be. The germs in a cough will travel about an arm's length and then drop to the floor. If someone inhales while another person coughs directly into his or her face, the respiratory air stream will carry germs deep into the lungs. When a few germs land on a person's hands, however, or are inhaled in a large spacious room or outdoors, the immune system starts to process the pathogen in the tonsils and adenoids. This immune surveillance system can be effective enough that a person exposed to a bug doesn't get sick. In the days before the chickenpox vaccine, some children suffered milder cases than others. The kids who were exposed to the virus in small doses over several days (ie, in a well-ventilated classroom with all the desks facing forward) tended to have a milder version than those whose first contact was more intense, ie, with an affectionate sibling during the most contagious phase of the virus when the spots were just beginning to appear.
Building the antibody library
One reason children in nursery school or daycare are so prone to getting colds is that they run around an indoor space all day with other children of the same size, coughing into each other's faces. When the children head home, they freely cough into their parents' faces and pass on the newest circulating virus. As the months go by, a new preschooler gradually builds up an elaborate library of antibodies. Often, by the time kids start grammar school, they get sick only rarely. In the 1950s a study reported that kindergarteners missed an average of 30 school days a year. The reason was their vulnerability to modern-day vaccine preventable illnesses: measles, mumps, rubella, and chickenpox.
Protect the new sibling
The preschooler with a newborn sibling at home is a particular challenge. Parents can’t, and shouldn’t, keep the older sibling away from the newborn. The easiest way to protect the infant is to have the child wash his hands with an alcohol-based hand sanitizer as soon as he is picked up at school or when he enters the house. Have the affectionate older child learn to kiss the baby on the feet (or top of the head or hands) instead of the face. At family gatherings, infants should be kept out of the coughing and touching range of other partygoers. Infant carriers are particularly helpful because they help keep the baby in the respiratory air zone of the parent and less likely to be passed around the room, from person to person.
There are many over-the-counter products from A (Airborne) to Z (zinc tablets) that are marketed as adjuncts in the prevention of common colds. Some alleviate symptoms, others enhance resistance. The human immune system is elaborate and many of the processes behind the immune response are still unclear. I don’t have the magic potion for prevention or cure, but here I offer some nutritional approaches and home treatments I’ve found helpful.
Green tea contains catechins which have been shown in studies of nursing home residents to help decrease the adhesion of influenza virus to receptors on the back of the throat. Green tea gargles were proposed as a possible preventive measure for nursing home staff and patients.
Cranberry, pomegranate, Concord grape, and several other fruits contain proanthocyanidins, which inhibit several viruses and also help block the viral receptor hemagglutinin.
Vitamin D has been shown to increase the efficacy of monocytes. Widespread vitamin D deficiency during the early years of the industrial revolution is now thought to have helped propel the spread of tuberculosis in city dwellers.
Vitamin C–containing fluids help reduce the viscosity of respiratory secretions and improve immune resistance within the mucous layer.
Keep the immune system strong
Get enough sleep: Sleep deprivation reduces human resistance.
Eat a balanced diet: Include fruits, vegetables, and proteins; all help optimize immunity.
Exercise outdoors: Walking outdoors, and particularly in the cold, makes the nasal passages produce a wave of protective clear mucus that helps clear away germs.
Stay warm: It’s also important to stay warm during the cold months. Prolonged sitting/standing in cold temperatures can weaken immune defense. We have all heard people complain of a cold getting worse after they’ve been “chilled.” The influenza virus prefers a cooler nostril and prolonged cold can even promote replication. Drinking warm liquids after exercising in the cold helps prevent the virus from settling in.