Know the common substance: Table salt (sodium chloride, NaCl)
The earliest record of salt usage was about 4,700 years agoin ancient China, where more than 40 different types of saltwere available.1 Ancient documentations were also found inEgypt around 4000BC, followed by Greece and Rome.2 Inancient Rome, salt was used as a currency and it is believedthat the English word “salary” actually originated from the Latin(salarium, meaning a payment made in salt).
The chemical name of common table salt is sodium chloride(NaCl), which appears as white isometric cubic crystals (Figure1). Natural salt is harvested from salt water, either the sea orsalt springs, by evaporation. The commonest used of salt isfor flavouring in cooking. Other usage of salt in the communityincludes the use of salt to produce fermented food and inhibitbacteria and fungal growth.
History of Salt. Salt Institute. http://www.saltinstitute.org/38.html (accessed 10 Dec 2008).
Kurlansky M, Schindler SD. The Story of Salt. G.P. Putnam’s Sons, New York, 2006.
Salt and health. Scientific Advisory Committee On Nutrition. 2003. http://www.sacn.gov.uk/pdfs/
sacn_salt_final.pdf (accessed 10 Dec 2008).
Cook NR, Cutler JA, Obarzanek E, et al. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP). BMJ. 2007;334(7599):885.
Hooper L, BartlettC, Davey SG, Ebrahim S. Advice to reduce dietary salt for prevention of cardiovascular disease. Cochrane Database Syst Rev. 2004;(1):CD003656.
Dietary Guidelines for Americans. Department of Health Service (HHS). 2005. http://www.cnpp.usda.gov/dietaryguidelines.htm(accessed 15 Dec 2008).