History and impact of nutritional epidemiology.

The real and important role of epidemiology was discussed, noting heretofore unknown associations that led to improved understanding of the cause and prevention of individual nutritional deficiencies. However, epidemiology has been less successful in linking individual nutrients to the cause of chronic diseases, such as cancer and cardiovascular disease. Dietary changes, such as decreasing caloric intake to prevent cancer and the Mediterranean diet to prevent diabetes, were confirmed as successful approaches to modifying the incidence of chronic diseases.

The discovery of vitamin C.

The term 'scurvy' for the disease resulting from prolonged vitamin C deficiency had origins in 'scorbutus' (Latin), 'scorbut' (French), and 'Skorbut' (German). Scurvy was a common problem in the world's navies and is estimated to have affected 2 million sailors. In 1747, James Lind conducted a trial of six different treatments for 12 sailors with scurvy: only oranges and lemons were effective in treating scurvy.

The discovery of thiamin.

Thiamin deficiency was long known as 'beriberi' in English and 'kakké' in Japan and China. The cause of beriberi was attributed to miasmas rising from wet soil and later to an unknown infectious organism. Systematic studies of beriberi began in the Dutch East Indies in the 1880s.

Acute versus marginal deficiencies of nutrients.

Under experimental conditions, an acute nutrient deficiency (e.g., thiamin or folic acid) can be induced in both animal and human subjects.