Most Susceptible Babies And Women

As people grow older, they generally have fewer colds. The graph at left documents the drop-off in the incidence of respiratory disease over the average lifetime, as traced in a six-year study of 4,905 males and females in Tecumseh, Michigan. The researchers’ figures lump together all respiratory illness, including influenza, bronchitis and pneumonia, as well as colds, but colds were by far the most frequent complaint.

The decline in the number of colds is not steady; a dramatic reduction in an individual’s susceptibility to respiratory ailments occurs during the first 20 years of life. An average infant has a sniffly existence, suffering 6.1 colds and other respiratory infections before the age of one. By the late teens, a person will encounter only 2.5 such illnesses yearly; presumably, resistance has been stiffened by the colds endured at a younger age.
From young adulthood on, the decline in the number of annual colds continues more slowly. Respiratory ailments make a brief comeback among people in their twenties. During those childrearing years, a couple’s children are likely to pass some of their numerous colds on to the parents.

Gender makes a surprising difference. Mothers usually have closer contact with their children than fathers do, and this fact may help explain why women in their twenties and thirties experience so many more respiratory diseases than men of the same age, But elderly women and young girls are also stricken more often than males of the same ages; the only exception to this rule is boys aged three or younger. The male-female discrepancy is one of the mysteries of the common cold that continue to puzzle medical researchers.