“ We are indeed much more than we eat, but what we eat nevertheless helps us to be much more than we are.” A century ago our ancestors feared infectious and communicable diseases such as smallpox -- diseases that claimed many children’s lives and limited the average life expectancy of adults. Today far fewer infectious diseases threaten us, thanks to medical science’s ability to identify disease-causing microorganisms and develop vaccines. In developed nations, purification of water prevents the spread of infections, and immunizations protect individuals. Most people live well into their later years, and today’s average life expectancy far