It seems like sugar might be the drug we all need to avoid according to this book. I'm trying but it is difficult...

"Simply stated, sugar lowers immunity. In 1951, Benjamin Sandler, M.D., a physician from Northern Carolina, wrote a book entitled Diet Prevents Polio. Dr. Sandler's work with rabbits and monkeys convinced him that high amounts of sugar in the diet made one more susceptible to polio. During the polio epidemic of 1948-49, he appeared on an Asheville radio station urging parents not to feed their children refined sugar or foods containing sugar such as ice cream, candy, and soft drinks. His admonitions also ran in local newspapers. In 1948, the incidence of polio in Northern Carolina was 2,402 cases. In 1949, after adopting the "Sandler diet," the rate had fallen to 214 cases. During this time, the national incidence of polio (39 states) had risen."

http://www.whale.to/v/sandler8.html