In 1949, Dr. Benjamin Sandler noticed a correlation between the incidence of polio and ice cream consumption, and concluded that sugar made children susceptible to the disease. Public health officials issued warnings. As it turned out, a third variable—warm weather—caused both an increase in disease (viruses become more active in the summer) and an increase in ice cream consumption.
GEORGE MARKS/GETTY IMAGES
BETTMANN/CORBIS
BETTMANN/CORBIS