Deficiency disease
Illnesses caused not by germs but by missing nutrients, such as scurvy from too little vitamin C and pellagra from too little niacin.
A deficiency disease is caused by the lack of something the body needs, rather than by an infection. Because such illnesses can strike many people who eat the same poor diet, they were often mistaken for contagious diseases.
Scurvy comes from a shortage of vitamin C, which the body needs to make collagen, the protein that holds skin, gums and blood vessels together. Without it, gums bleed, old wounds reopen and people grow weak. It killed huge numbers of sailors on long voyages without fresh food. In May 1747 the naval surgeon James Lind took 12 sailors with scurvy aboard HMS Salisbury and gave them different treatments; those given oranges and lemons improved fastest, and one was fit for duty after six days. Fresh meat that is eaten raw or lightly cooked also contains some vitamin C, which helped some polar crews survive.
Pellagra is caused by a lack of niacin (vitamin B3) and is remembered by four Ds: dermatitis, diarrhoea, dementia and death. It spread with diets based heavily on maize. In the United States between 1906 and 1940 there were about 3 million cases and 100,000 deaths. Joseph Goldberger showed it was dietary, not infectious. Indigenous Americans had long avoided it by soaking maize in an alkaline solution of lye or lime, a process called nixtamalization, which turns its bound niacin into a form the body can absorb.
Both diseases can be cured by restoring the missing nutrient.
Coming up in future stories
- The Doctor Who Threw Filth Parties 1916 · USA (Mississippi and South Carolina)
- The Explorer Who Ate Only Meat for a Year 28 Feb 1928 – Mar 1929 · Bellevue Hospital, New York
- The Fizzy Water Meant to Cure Scurvy 1772 · Leeds and London, England
- The Prisoners Who Volunteered for Pellagra 1915–1916 · Rankin Prison Farm, Mississippi
- Twelve Sick Sailors and the First Clinical Trial 1747 · HMS Salisbury, Bay of Biscay