Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Table Salt shopping experience:
1. Compare - without doubt the biggest advantage that the Table Salt offers shoppers today is the ability to compare thousands of Table Salt at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Table Salt? Wrong! If the Table Salt is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Table Salt then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Table Salt? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Table Salt and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Table Salt wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Table Salt then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Table Salt site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Table Salt, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Table Salt, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
, which some use to prevent caking, China
Salt is a
mineral Dietary mineral for
animal life, composed primarily of sodium chloride. Salt for human consumption is produced in different forms: unrefined salt (such as sea salt), refined salt (
sodium chloride), and iodised salt. It is a crystalline solid, white, pale pink or light grey in color, normally obtained from
sea water or rock deposits. Edible rock salts may be slightly greyish in color due to this mineral content.
Sodium and chlorine, the two components of salt, are necessary for the survival of all living creatures, including humans, but they need not be consumed as salt, where they are found together in very concentrated form. Some isolated cultures, such as the
Yanomami in South America, have been found to consume little salt. Yanomami Indians in the INTERSALT study, (accessed
13 January,
2007) Salt is involved in regulating the water content (fluid balance) of the body. Salt
flavor is one of the
basic tastes. Salt cravings may be caused by trace mineral deficiencies as well as by a deficiency of sodium chloride itself.
Overconsumption of salt can increase the risk of health problems, including
hypertension. In food preparation, salt is used as a
preservative and as a
seasoning.
History
See main article: History of salt
At the dawn of civilization, salt's preservative ability eliminated dependency on the seasonal availability of food, allowed travel over long distances, and was a vital food additive. However, because salt (NaCl) was difficult to obtain, it became a highly valued trade item throughout history. Until the
1900s, salt was one of the prime movers of national economies and wars. Salt was often taxed; research has discovered this practice to have existed as early as the 20th century BC in China. By the Middle Ages,
camel trains consisting of as many as forty thousand
camels traversed four hundred miles of the
Sahara bearing salt, sometimes trading it for slavery.
The first registers of salt use were produced around 4000 BC in Egypt, and later in Greece and
Rome. Salt was very valuable and used to preserve and flavor foods. In Ancient Rome, salt was used as a currency. The Latin word
salarium; meaning a payment made in salt, is the root of the word "
salary." Unfortunately for those paid with salt, it was easily ruined by rain and other weather conditions. Payments to Roman workers and soldiers were made in salt.Bloch, David: Economics of NaCl: Salt made the world go round Salt was also given to the parents of the
groom in marriage until the 8th century.
From the Phoenicians dates the evidence of harvesting solid salt from the sea. They also exported it to other civilizations. As a result of the increased salt supply from the sea, the value of salt depreciated. The harvest method used was flooding plains of land with seawater, then leaving the plains to dry. After the water dried, the salt which was left was collected and sold.
In the Mali Empire, merchants in
12th century Timbuktu—the gateway to the Sahara Desert and the seat of scholars—valued salt (NaCl) enough to buy it for its weight in gold; this trade led to the legends of the incredibly wealthy city of Timbuktu, and fueled
inflation in Europe, which was importing the salt. Take a journey to Timbuktu, 13 January 2007 (accessed13 January,2007)
During his protests in India, Mohandas Gandhi performed the famous
Salt Satyagraha to challenge the
British Raj-imposed monopoly on salt.
In religion
Among the ancients, as with ourselves, "
sol" (sun) and "
sal" (salt) were considered essential to the maintenance of life.
There are thirty-five references (verses) to salt in the
Bible (King James Version), the most familiar probably being the story of Lot (biblical) wife, who was turned into a pillar of salt when she disobeyed the
angels and looked back at the wicked city of
Sodom and Gomorrah (
Genesis 19:26). In the
Sermon on the Mount,
Jesus also referred to his followers as the "salt of the earth". The apostle Paul also encouraged Christians to "let your conversation be always full of grace, seasoned with salt" (Colossians 4:6) so that when others enquire about their beliefs, the Christian's answer generates a 'thirst' to know more about Christ. Salt is mandatory in the rite of the Tridentine Mass. Salt is used in the third item (which includes an Exorcism) of the
Celtic Consecration (refer
Gallican rite) that is employed in the Consecration of a Church. Salt may be added to the water "where it is customary" in the Roman Catholic rite of Holy water. The earliest Biblical mention of salt appears to be in reference to the destruction of
Sodom and
Gomorrah (Genesis 19:24-26)When King Abimelech destroyed the city of Shechem, held to have occurred in the thirteenth century BCE., he is said to have "sowed salt on it," this phrase expressing the completeness of its ruin. (Judges 9:45.)
In the native Japanese religion
Shinto, salt is used for ritual purification of locations and people, such as in Sumo Wrestling.
In Aztec mythology, Huixtocihuatl was a fertility goddess who presided over salt and salt water.
Forms of salt
Unrefined salt
,
Senegal.Different natural salts have different mineralities, giving each one a unique flavor.
Fleur de sel, natural sea salt harvested by hand, has a unique flavor varying from region to region.
Some assert that unrefined sea salt is more healthy than refined salts.http://www.gomanzanillo.com/features/salt/index.htm However, completely raw sea salt is bitter due to magnesium and calcium compounds, and thus is rarely eaten. Other people think that raw sea and rock salts do not contain sufficient
iodine salts to prevent iodine deficiency diseases like
hypothyroidism.http://www.saltinstitute.org/iodine-seasalt.html
Refined salt
image:Piles of Salt Salar de Uyuni Bolivia Luca Galuzzi 2006 a.jpg.Refined salt, which is most widely used presently, is mainly sodium chloride. Food grade salt accounts for only a small part of salt production in industrialised countries (3% in EuropeEuropean Salt Producers' Association http://www.eu-salt.com/index3.htm) although world-wide, food uses account for 17.5% of salt productionRoskill Information Services http://www.roskill.com/reports/salt. The majority is sold for industrial use. Salt has great commercial value, because it is a necessary ingredient in the manufacturing of many things. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.
The manufacture and use of salt is one of the oldest chemical industries.http://www.salt.org.il/arch.html Salt is also obtained by evaporation of
sea water, usually in shallow basins warmed by sunlight;http://nauticus.org/currwthrless043.html salt so obtained was formerly called bay salt, and is now often called sea salt or solar salt. Today, most refined salt is prepared from rock salt: mineral deposits high in salt. These rock salt deposits were formed by the evaporation of ancient salt lakes.UK Salt Manufacturers' Association http://www.saltsense.co.uk/aboutsalt-what01.htm These deposits may be
mining conventionally or through the injection of water. Injected water dissolves the salt, and the brine solution can be pumped to the surface where the salt is collected.
After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts).http://www.saltsense.co.uk/aboutsalt-prod02.htm Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are
kiln-dried.
Since the 1950's it has been common to add a trace of sodium hexacyanoferrate II to the brine; this acts as an anticaking agent by promoting irregular crystals.http://www.saltsense.co.uk/hist-chem08.htm Other
anticaking agents (and potassium iodide, for iodised salt) are generally added after crystallization. These agents are
hygroscopic chemicals which absorb
humidity, keeping the salt crystals from sticking together. Some anticaking agents used are
tricalcium phosphate,
calcium carbonate or magnesium carbonates,
fatty acid salts (acid salts), magnesium oxide, silicon dioxide, calcium silicate, sodium alumino-silicate, and alumino-calcium
silicate. Concerns have been raised regarding the possible toxic effects of aluminium in the latter two compounds; however, both the European Union and the United States
Food and Drug Administration (FDA) permit their use. http://www.ces.purdue.edu/extmedia/HE/HE-625.html The refined salt is then ready for packing and distribution.
Table salt
Table salt is refined salt, 99%
sodium chloride.Nutritional analysis provided with Tesco Table Salt, from Tesco Stores Ltd (UK) states 38.9% sodium by weight which equals 98.9% sodium chloridehttp://www.wasalt.com.au/Table.html It usually contains substances that make it free flowing (anticaking agents) such as sodium silicoaluminate or magnesium carbonate. It is common practice to put a few grains of uncooked rice in salt shakers to absorb extra moisture when anticaking agents are not enough.
Iodized salt
Iodized salt (
British English:
iodised salt),
table salt mixed with a minute amount of potassium iodide, or sometimes sodium iodide, or
sodium iodate, is used to help reduce the chance of
iodine deficiency in humans. Iodine deficiency commonly leads to thyroid gland problems, specifically endemic
Goitre. Endemic goiter is a disease characterized by a swelling of the thyroid gland, usually resulting in a bulbous protrusion on the neck. While only tiny quantities of iodine are required in a diet (nutrition) to prevent goiter, the United States Food and Drug Administration recommends (21 CFR 101.9 (c)(8)(iv)) 150
Kilogram#SI multiples of iodine per day for both men and women, and there are many places around the world where natural levels of iodine in the soil are low and the iodine is not taken up by vegetables.
Today, iodized salt is more common in the United States, Australia and New Zealand than in UK.Table salt is also often iodized—a small amount of potassium iodide (in the US) or
potassium iodate (in the EU) is added as an important dietary supplement. Table salt is mainly employed in cooking and as a table condiment. Iodized table salt has significantly reduced disorders of iodine deficiency in countries where it is used.http://www.saltinstitute.org/37.html Iodine is important to prevent the insufficient production of thyroid hormones (hypothyroidism), which can cause
goitre,
cretinism in children, and myxedema in adults.
Fluorinated salt
In some European countries where
Water fluoridation of drinking water is not practiced, fluorinated table salt is available. In France, 35% of sold table salt contains sodium fluoride or potassium fluoride.http://www.afssa.fr/Ftp/Afssa/26447-26448.pdf Another additive, especially important for pregnancy women, is
Folic acid (Vitamin B9), which gives the table salt a yellow color.
Salty condiments
In many Asian cultures, table salt is not traditionally used as a condiment.http://seattletimes.nwsource.com/pacificnw/2001/0729/taste.htmlHowever, condiments such as soy sauce, fish sauce and oyster sauce tend to have a high salt content and fill much the same role as a salt-providing table condiment that table salt serves in western cultures.
Health effects
Sodium is one of the primary electrolytes in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are available in unrefined salt, as are other vital minerals needed for optimal bodily function. Too much or too little salt in the diet can lead to
cramp,
dizziness, or even an
electrolyte disturbance, which can cause severe, even fatal, neurological problems.Australia: Better Health Channel (Australia, Victoria) Salt Drinking too much water, with insufficient salt intake, puts a person at risk of
water intoxication (hyponatremia). Salt is even sometimes used as a health aid, such as in treatment of dysautonomia. Cleveland Clinic Health Information Center Dysautonomia page
People's risk for disease due to insufficient or excessive salt intake varies due to biochemical individuality. Some have asserted that while the risks of consuming too much salt are real, the risks have been exaggerated for most people, or that the studies done on the consumption of salt can be interpreted in many different ways.Why Files article Salt and other woundsGary Taubes, "The (Political) Science of Salt",
Science, 14 August 1998, Vol. 281. no. 5379, pp. 898 - 907
Excess salt consumption has been linked to:
- exercise-induced asthma. Exercise-induced asthma more clearly linked to high-salt diet On the other hand, another source counters, "…we still don't know whether salt contributes to asthma. If there is a link then it's very weak…".Dr Trisha Macnair "Does eating salt make asthma worse?"
- heartburnEverybody Study adds salt to suspected triggers for heartburn.
- osteoporosis: One report shows that a high salt diet does reduce bone density in girls. High salt diet reduces bone density in girls. Yet "While high salt intakes have been associated with detrimental effects on bone health, there are insufficient data to draw firm conclusions." (Scientific Advisory Committee on Nutrition (SACN) Salt and Health (PDF), p3)
- Gastric cancer (Stomach cancer) is associated with high levels of sodium, "but the evidence does not generally relate to foods typically consumed in the UK." (, p18) However, in Japan, salt consumption is higher. Salt raises 'stomach cancer risk'
- hypertension (high blood pressure): "Since 1994, the evidence of an association between dietary salt intakes and blood pressure has increased. The data have been consistent in various study populations and across the age range in adults." ( p3). Professor Dr. Diederick Grobbee claims that there is no evidence of a causal link between salt intake and mortality or cardiovascular events. Salt Manufacturers' Association press release. One study found that low urinary sodium is associated with greater risk of myocardial infarction among treated hypertensive men Michael H. Alderman; Shantha Madhavan; Hillel Cohen; Jean E. Sealey; John H. Laragh Low Urinary Sodium Is Associated With Greater Risk of Myocardial Infarction Among Treated Hypertensive Men Hypertension 1995;25:1144-1152..
- left ventricular hypertrophy (cardiac enlargement): "Evidence suggests that high salt intake causes left ventricular hypertrophy, a strong risk factor for cardiovascular disease, independently of blood pressure effects." ( p3) "…there is accumulating evidence that high salt intake predicts left ventricular hypertrophy." (Food Safety Authority of Ireland Salt and Health: Review of the Scientific Evidence and Recommendations for Public Policy in Ireland, p12) Excessive salt (sodium) intake, combined with an inadequate intake of water, can cause hypernatremia. It can exacerbate renal disease.
- edema (British English: oedema): A decrease in salt intake has been suggested to treat edema (fluid retention).Australia: Better Health Channel (Australia, Victoria) Fluid retention
- Peptic ulcer and Peptic ulcerBBC High-salt diet link to ulcer risk 22 May 2007
A large scale study by Nancy Cook
et al shows that people with high-normal blood pressure who significantly reduced the amount of salt in their diet decreased their chances of
developing cardiovascular disease by 25% over the following 10 to 15 years. Their risk of
dying from cardiovascular disease decreased by 20%.
BBC News Cutting salt 'reduces heart risk' 19 April 2007 Eating less salt could prevent cardiovascular disease
Recommended intake
This section summarizes the salt intake recommended by the health agencies of various countries. Recommendations tend to be similar. Note that targets for the population as a whole tend to be pragmatic (what is achievable) while advice for an individual is ideal (what is best for health). For example, in the UK target for the population is "eat no more than 6 g a day" but for a person is 4 g.
Intakes can be expressed variously as salt or sodium and in various units.
- 1 g sodium = 1,000 mg sodium = 42 mmol sodium = 2.5 g salt
United Kingdom: In 2003, the UK's Scientific Advisory Committee on Nutrition (SACN) recommended that, for a typical adult, the
Reference Nutrient Intake is 4 g salt per day (1.6 g or 70 mmol sodium). However, average adult intake is two and a half times the Reference Nutrient Intake for sodium. "Although accurate data are not available for children, conservative estimates indicate that, on a body weight basis, the average salt intake of children is higher than that of adults." SACN aimed for an achievable target reduction in average intake of salt to 6 g per day (2.4 g or 100 mmol sodium) — this is roughly equivalent to a teaspoonful of salt. The SACN recommendations for children are:
- 0–6 months old: less than 1 g/day
- 7–12 months: 1 g/day
- 1–3 years: 2 g/day
- 4–6 years: 3 g/day
- 7–10 years: 5 g/day
- 11–14 years: 6 g/day
SACN states, "The target salt intakes set for adults and children do not represent ideal or optimum consumption levels, but achievable population goals."
Republic of Ireland: The Food Safety Authority of Ireland endorses the UK targets "emphasising that the RDA of 1.6 g sodium (4 g salt) per day should form the basis of advice targeted at individuals as distinct from the population health target of a mean salt intake of 6 g per day."(, p16)
Canada: Health Canada recommends an Adequate Intake (AI) and an Upper Limit (UL) in terms of
sodium.
- 0–6 months old: 0.12 g/day (AI)
- 7–12 months: 0.37 g/day (AI)
- 1–3 years: 1 g/day (AI) 1.5 g/day (UL)
- 4–8 years: 1.2/day (AI) 1.9 g/day (UL)
- 9–13 years: 1.5 g/day (AI) 2.2 g/day (UL)
- 14–50 years: 1.5 g/day (AI) 2.3 g/day (UL)
- 51–70 years: 1.3 g/day (AI) 2.3 g/day (UL)
- 70 years and older: 1.2 g/day (AI) 2.3 g/day (UL)Health Canada Dietary Reference Intakes (look for Sodium)
New Zealand
- Adequate Intake (AI) 0.46 – 0.92 g sodium = 1.2 – 2.3g salt
- Upper Limit (UL)) 2.3 g sodium = 5.8 g saltAuckland District Health Board Public Health Nutrition Advice (PDF)
Australia: The recommended dietary intake (RDI) is 0.92 g–2.3 g sodium per day (= 2.3 g–5.8 g salt)Better Health Channel (Australia, Victoria) Salt
USA: The Food and Drug Administration itself does not make a recommendationU. S. Food and Drug Administration A Pinch of Controversy Shakes Up Dietary Salt but refers readers to
Dietary Guidelines for Americans 2005. These suggest that US citizens should consume less than 2,300 mg of sodium (= 2.3 g sodium = 5.8 g salt) per day.Department of Health and Human Services (HHS) and the Department of Agriculture (USDA)
Dietary Guidelines for Americans 2005 "Sodium and Potassium"
Labeling
UK: The Food Standards Agency defines the level of salt in foods as follows: "High is more than 1.5g salt per 100g (or 0.6g sodium). Low is 0.3g salt or less per 100g (or 0.1g sodium). If the amount of salt per 100g is in between these figures, then that is a medium level of salt." In the UK, foods produced by some supermarkets and manufacturers have ‘traffic light’ colors on the front of the pack: Red (High), Amber (Medium), or Green (Low). Understanding labels
USA: The FDA
Food Labeling Guide stipulates whether a food can be labelled as "free", "low", or "reduced/less" in respect of sodium. When other health claims are made about a food (e.g. low in fat, calories, etc.), a disclosure statement is required if the food exceeds 480mg of sodium per 'serving.'Food and Drug Administration A Food Labeling Guide--Appendix A
Campaigns
In 2004, Britain's
Food Standards Agency started a public health campaign called "Salt - Watch it", which recommends no more than 6g of salt per day; it features a character called Sid the Slug and was criticised by the Salt Manufacturers Association (SMA).Salt Manufacturers Association press release New salt campaign under attack The Advertising Standards Authority did not uphold the SMA complaint in its adjudication.Advertising Standards Authority Broadcast Advertising Adjudications: 20 April 2005 (PDF). In March 2007, the FSA launched the third phase of their campaign with the slogan "Salt. Is your food full of it?" fronted by comedienne Jenny Eclair. Salt TV ads
The Menzies Research Institute in Tasmania, Australia, maintains a website Salt Matters dedicated to educating people about the potential problems of a salt-laden diet.
Salt substitutes
Salt intake can be reduced by simply reducing the quantity of salty foods in a diet, without recourse to salt substitutes. Salt substitutes have a taste similar to table salt and contain mostly potassium chloride, which will increase potassium intake. Excess potassium intake can cause hyperkalemia. Various diseases and medications may decrease the body's excretion of potassium, thereby increasing the risk of hyperkalemia. If you have kidney failure, heart failure or diabetes, seek medical advice before using a salt substitute. A manufacturer, LoSalt, has issued an advisory statementLoSalt Advisory Statement (PDF) that people taking the following prescription drugs should not use a salt substitute: Amiloride, Triamterene, Dytac,
Spironolactone (Brand name Aldactone),
Eplerenone and
Inspra.
Production trends
Salt is produced by evaporation of seawater or brine from other sources, such as brine wells and
salt lake (geography)s, and by salt mine
rock salt, called halite. In 2002, total world production was estimated at 210 million metric tonnes, the top five producers being the United States (40.3 million tonnes), China (32.9), Germany (17.7), India (14.5), and Canada (12.3).Susan R. Feldman. Sodium chloride.
Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. Published online
2005. Note that these figures are not just for table salt but for sodium chloride in general.
See also
References
External links
- Salt production methods and practices
- Salt Institute
- Cook's Thesaurus: Salt (Summary and descriptions of edible salts)
Salt and health
Government bodies
Many other government bodies are listed in the References section above.
- Ireland: Food Safety Authority of Ireland Salt and Health
- UK: Food Standards Agency Salt campaign
- UK: Scientific Advisory Committee on Nutrition (SACN) Salt and Health (PDF) and Salt Subgroup minutes
- UK: Why 6g? A summary of the scientific evidence for the salt intake target
Medical authorities
- The Cochrane Collaboration "Effect of longer-term modest salt reduction on blood pressure"
- Menzies Research Institute Salt Matters Web Site
Charities and campaigns
- British Nutrition Foundation article "Salt in the Diet"
- Consensus Action on Salt and Health (UK charity)
- Action on Salt and Health
- CSPI page Salt: The Forgotten Killer
- Irish Heart Foundation booklet Time to cut down on salt (PDF format)
Journalism
- BBC article "Salt: friend or foe?"
- BBC medical notes "Salt"
- Guardian article The sceptic
- Ockham's Razor Salt matters - talk by Dr Trevor Beard, Menzies Research Institute (ABC Radio National 4th February 2007)
Salt industry
- EuSalt Position papers
- LoSalt (salt substitute manufacturer)
- Salt Manufacturers' Association Salt and health
- Salt Institute Sodium and health
- Bloch, David: Economics of NaCl: Salt made the world go round.
Chemical data
Further reading
- Mark Kurlansky, Salt : A World History (Penguin Books, 2002). ISBN 0802713734.
- Kurlansky, Mark, and S. D. Schindler. The Story of Salt. New York, NY: G.P. Putnam's Sons, 2006. ISBN 0399239987 -- a children's book about salt.
- Laszlo, Pierre. Salt: Grain of Life. Arts and traditions of the table. New York: Columbia University Press, 2001.
- Department of Health, Dietary Reference Values for Food Energy and Nutrients for the UK: Report of the Panel on DRVs of the Committee on the Medical Aspects of Food Policy , The Stationery Office.
, which some use to prevent caking, China
Salt is a
mineral Dietary mineral for animal life, composed primarily of
sodium chloride. Salt for human consumption is produced in different forms: unrefined salt (such as sea salt), refined salt (sodium chloride), and
iodised salt. It is a crystalline solid, white, pale pink or light grey in color, normally obtained from
sea water or rock deposits. Edible rock salts may be slightly greyish in color due to this mineral content.
Sodium and chlorine, the two components of salt, are necessary for the survival of all living creatures, including humans, but they need not be consumed as salt, where they are found together in very concentrated form. Some isolated cultures, such as the Yanomami in South America, have been found to consume little salt. Yanomami Indians in the INTERSALT study, (accessed
13 January,
2007) Salt is involved in regulating the water content (fluid balance) of the body. Salt flavor is one of the basic tastes. Salt cravings may be caused by trace mineral deficiencies as well as by a deficiency of sodium chloride itself.
Overconsumption of salt can increase the risk of health problems, including
hypertension. In food preparation, salt is used as a preservative and as a seasoning.
History
See main article: History of salt
At the dawn of civilization, salt's preservative ability eliminated dependency on the seasonal availability of food, allowed travel over long distances, and was a vital food additive. However, because salt (NaCl) was difficult to obtain, it became a highly valued trade item throughout history. Until the
1900s, salt was one of the prime movers of national economies and wars. Salt was often taxed; research has discovered this practice to have existed as early as the 20th century BC in China. By the Middle Ages, camel trains consisting of as many as forty thousand camels traversed four hundred miles of the
Sahara bearing salt, sometimes trading it for slavery.
The first registers of salt use were produced around 4000 BC in
Egypt, and later in Greece and
Rome. Salt was very valuable and used to preserve and flavor foods. In Ancient Rome, salt was used as a
currency. The Latin word
salarium; meaning a payment made in salt, is the root of the word "
salary." Unfortunately for those paid with salt, it was easily ruined by rain and other weather conditions. Payments to Roman workers and soldiers were made in salt.Bloch, David: Economics of NaCl: Salt made the world go round Salt was also given to the parents of the groom in marriage until the 8th century.
From the
Phoenicians dates the evidence of harvesting solid salt from the sea. They also exported it to other civilizations. As a result of the increased salt supply from the sea, the value of salt depreciated. The harvest method used was flooding plains of land with seawater, then leaving the plains to dry. After the water dried, the salt which was left was collected and sold.
In the Mali Empire, merchants in 12th century Timbuktu—the gateway to the Sahara Desert and the seat of scholars—valued salt (NaCl) enough to buy it for its weight in
gold; this trade led to the legends of the incredibly wealthy city of Timbuktu, and fueled
inflation in
Europe, which was importing the salt. Take a journey to Timbuktu, 13 January 2007 (accessed13 January,
2007)
During his protests in India, Mohandas Gandhi performed the famous Salt Satyagraha to challenge the
British Raj-imposed monopoly on salt.
In religion
Among the ancients, as with ourselves, "
sol" (sun) and "
sal" (salt) were considered essential to the maintenance of life.
There are thirty-five references (verses) to salt in the Bible (King James Version), the most familiar probably being the story of Lot (biblical) wife, who was turned into a pillar of salt when she disobeyed the
angels and looked back at the wicked city of Sodom and Gomorrah (Genesis 19:26). In the Sermon on the Mount,
Jesus also referred to his followers as the "salt of the earth". The apostle Paul also encouraged Christians to "let your conversation be always full of grace, seasoned with salt" (Colossians 4:6) so that when others enquire about their beliefs, the Christian's answer generates a 'thirst' to know more about Christ. Salt is mandatory in the rite of the Tridentine Mass. Salt is used in the third item (which includes an Exorcism) of the
Celtic Consecration (refer Gallican rite) that is employed in the Consecration of a Church. Salt may be added to the water "where it is customary" in the Roman Catholic rite of
Holy water. The earliest Biblical mention of salt appears to be in reference to the destruction of Sodom and Gomorrah (Genesis 19:24-26)When
King Abimelech destroyed the city of
Shechem, held to have occurred in the thirteenth century BCE., he is said to have "sowed salt on it," this phrase expressing the completeness of its ruin. (Judges 9:45.)
In the native Japanese religion Shinto, salt is used for ritual purification of locations and people, such as in Sumo Wrestling.
In Aztec mythology, Huixtocihuatl was a fertility goddess who presided over salt and salt water.
Forms of salt
Unrefined salt
,
Senegal.Different natural salts have different mineralities, giving each one a unique flavor. Fleur de sel, natural sea salt harvested by hand, has a unique flavor varying from region to region.
Some assert that unrefined sea salt is more healthy than refined salts.http://www.gomanzanillo.com/features/salt/index.htm However, completely raw sea salt is bitter due to magnesium and calcium compounds, and thus is rarely eaten. Other people think that raw sea and rock salts do not contain sufficient iodine salts to prevent iodine deficiency diseases like
hypothyroidism.http://www.saltinstitute.org/iodine-seasalt.html
Refined salt
image:Piles of Salt Salar de Uyuni Bolivia Luca Galuzzi 2006 a.jpg.Refined salt, which is most widely used presently, is mainly sodium chloride. Food grade salt accounts for only a small part of salt production in industrialised countries (3% in EuropeEuropean Salt Producers' Association http://www.eu-salt.com/index3.htm) although world-wide, food uses account for 17.5% of salt productionRoskill Information Services http://www.roskill.com/reports/salt. The majority is sold for industrial use. Salt has great commercial value, because it is a necessary ingredient in the manufacturing of many things. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.
The manufacture and use of salt is one of the oldest chemical industries.http://www.salt.org.il/arch.html Salt is also obtained by evaporation of sea water, usually in shallow basins warmed by sunlight;http://nauticus.org/currwthrless043.html salt so obtained was formerly called bay salt, and is now often called sea salt or solar salt. Today, most refined salt is prepared from rock salt: mineral deposits high in salt. These rock salt deposits were formed by the evaporation of ancient salt lakes.UK Salt Manufacturers' Association http://www.saltsense.co.uk/aboutsalt-what01.htm These deposits may be
mining conventionally or through the injection of water. Injected water dissolves the salt, and the brine solution can be pumped to the surface where the salt is collected.
After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts).http://www.saltsense.co.uk/aboutsalt-prod02.htm Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are
kiln-dried.
Since the 1950's it has been common to add a trace of sodium hexacyanoferrate II to the brine; this acts as an anticaking agent by promoting irregular crystals.http://www.saltsense.co.uk/hist-chem08.htm Other anticaking agents (and
potassium iodide, for iodised salt) are generally added after crystallization. These agents are hygroscopic chemicals which absorb
humidity, keeping the salt crystals from sticking together. Some anticaking agents used are tricalcium phosphate, calcium carbonate or
magnesium carbonates,
fatty acid salts (acid salts),
magnesium oxide,
silicon dioxide,
calcium silicate, sodium alumino-silicate, and alumino-calcium
silicate. Concerns have been raised regarding the possible toxic effects of
aluminium in the latter two compounds; however, both the European Union and the United States
Food and Drug Administration (FDA) permit their use. http://www.ces.purdue.edu/extmedia/HE/HE-625.html The refined salt is then ready for packing and distribution.
Table salt
Table salt is refined salt, 99%
sodium chloride.Nutritional analysis provided with Tesco Table Salt, from Tesco Stores Ltd (UK) states 38.9% sodium by weight which equals 98.9% sodium chloridehttp://www.wasalt.com.au/Table.html It usually contains substances that make it free flowing (anticaking agents) such as sodium silicoaluminate or magnesium carbonate. It is common practice to put a few grains of uncooked
rice in salt shakers to absorb extra moisture when anticaking agents are not enough.
Iodized salt
Iodized salt (
British English:
iodised salt), table salt mixed with a minute amount of potassium iodide, or sometimes sodium iodide, or
sodium iodate, is used to help reduce the chance of iodine deficiency in humans. Iodine deficiency commonly leads to thyroid gland problems, specifically endemic Goitre. Endemic goiter is a disease characterized by a swelling of the thyroid gland, usually resulting in a bulbous protrusion on the neck. While only tiny quantities of iodine are required in a
diet (nutrition) to prevent goiter, the
United States Food and Drug Administration recommends (21 CFR 101.9 (c)(8)(iv)) 150
Kilogram#SI multiples of iodine per day for both men and women, and there are many places around the world where natural levels of iodine in the soil are low and the iodine is not taken up by vegetables.
Today, iodized salt is more common in the United States, Australia and New Zealand than in
UK.Table salt is also often iodized—a small amount of
potassium iodide (in the US) or potassium iodate (in the EU) is added as an important dietary supplement. Table salt is mainly employed in cooking and as a table condiment. Iodized table salt has significantly reduced disorders of
iodine deficiency in countries where it is used.http://www.saltinstitute.org/37.html Iodine is important to prevent the insufficient production of thyroid hormones (hypothyroidism), which can cause
goitre, cretinism in children, and myxedema in adults.
Fluorinated salt
In some European countries where
Water fluoridation of drinking water is not practiced, fluorinated table salt is available. In France, 35% of sold table salt contains sodium fluoride or potassium fluoride.http://www.afssa.fr/Ftp/Afssa/26447-26448.pdf Another additive, especially important for pregnancy women, is
Folic acid (Vitamin B9), which gives the table salt a yellow color.
Salty condiments
In many Asian cultures, table salt is not traditionally used as a condiment.http://seattletimes.nwsource.com/pacificnw/2001/0729/taste.htmlHowever, condiments such as soy sauce,
fish sauce and oyster sauce tend to have a high salt content and fill much the same role as a salt-providing table condiment that table salt serves in western cultures.
Health effects
Sodium is one of the primary
electrolytes in the body. All four cationic electrolytes (sodium, potassium, magnesium, and calcium) are available in unrefined salt, as are other vital minerals needed for optimal bodily function. Too much or too little salt in the diet can lead to
cramp,
dizziness, or even an electrolyte disturbance, which can cause severe, even fatal, neurological problems.Australia: Better Health Channel (Australia, Victoria) Salt Drinking too much water, with insufficient salt intake, puts a person at risk of water intoxication (
hyponatremia). Salt is even sometimes used as a health aid, such as in treatment of
dysautonomia. Cleveland Clinic Health Information Center Dysautonomia page
People's risk for disease due to insufficient or excessive salt intake varies due to biochemical individuality. Some have asserted that while the risks of consuming too much salt are real, the risks have been exaggerated for most people, or that the studies done on the consumption of salt can be interpreted in many different ways.Why Files article Salt and other woundsGary Taubes, "The (Political) Science of Salt",
Science, 14 August 1998, Vol. 281. no. 5379, pp. 898 - 907
Excess salt consumption has been linked to:
- exercise-induced asthma. Exercise-induced asthma more clearly linked to high-salt diet On the other hand, another source counters, "…we still don't know whether salt contributes to asthma. If there is a link then it's very weak…".Dr Trisha Macnair "Does eating salt make asthma worse?"
- heartburnEverybody Study adds salt to suspected triggers for heartburn.
- osteoporosis: One report shows that a high salt diet does reduce bone density in girls. High salt diet reduces bone density in girls. Yet "While high salt intakes have been associated with detrimental effects on bone health, there are insufficient data to draw firm conclusions." (Scientific Advisory Committee on Nutrition (SACN) Salt and Health (PDF), p3)
- Gastric cancer (Stomach cancer) is associated with high levels of sodium, "but the evidence does not generally relate to foods typically consumed in the UK." (, p18) However, in Japan, salt consumption is higher. Salt raises 'stomach cancer risk'
- hypertension (high blood pressure): "Since 1994, the evidence of an association between dietary salt intakes and blood pressure has increased. The data have been consistent in various study populations and across the age range in adults." ( p3). Professor Dr. Diederick Grobbee claims that there is no evidence of a causal link between salt intake and mortality or cardiovascular events. Salt Manufacturers' Association press release. One study found that low urinary sodium is associated with greater risk of myocardial infarction among treated hypertensive men Michael H. Alderman; Shantha Madhavan; Hillel Cohen; Jean E. Sealey; John H. Laragh Low Urinary Sodium Is Associated With Greater Risk of Myocardial Infarction Among Treated Hypertensive Men Hypertension 1995;25:1144-1152..
- left ventricular hypertrophy (cardiac enlargement): "Evidence suggests that high salt intake causes left ventricular hypertrophy, a strong risk factor for cardiovascular disease, independently of blood pressure effects." ( p3) "…there is accumulating evidence that high salt intake predicts left ventricular hypertrophy." (Food Safety Authority of Ireland Salt and Health: Review of the Scientific Evidence and Recommendations for Public Policy in Ireland, p12) Excessive salt (sodium) intake, combined with an inadequate intake of water, can cause hypernatremia. It can exacerbate renal disease.
- edema (British English: oedema): A decrease in salt intake has been suggested to treat edema (fluid retention).Australia: Better Health Channel (Australia, Victoria) Fluid retention
- Peptic ulcer and Peptic ulcerBBC High-salt diet link to ulcer risk 22 May 2007
A large scale study by Nancy Cook
et al shows that people with high-normal blood pressure who significantly reduced the amount of salt in their diet decreased their chances of
developing cardiovascular disease by 25% over the following 10 to 15 years. Their risk of
dying from cardiovascular disease decreased by 20%.
BBC News Cutting salt 'reduces heart risk' 19 April 2007 Eating less salt could prevent cardiovascular disease
Recommended intake
This section summarizes the salt intake recommended by the health agencies of various countries. Recommendations tend to be similar. Note that targets for the population as a whole tend to be pragmatic (what is achievable) while advice for an individual is ideal (what is best for health). For example, in the UK target for the population is "eat no more than 6 g a day" but for a person is 4 g.
Intakes can be expressed variously as salt or sodium and in various units.
- 1 g sodium = 1,000 mg sodium = 42 mmol sodium = 2.5 g salt
United Kingdom: In 2003, the UK's Scientific Advisory Committee on Nutrition (SACN) recommended that, for a typical adult, the
Reference Nutrient Intake is 4 g salt per day (1.6 g or 70 mmol sodium). However, average adult intake is two and a half times the Reference Nutrient Intake for sodium. "Although accurate data are not available for children, conservative estimates indicate that, on a body weight basis, the average salt intake of children is higher than that of adults." SACN aimed for an achievable target reduction in average intake of salt to 6 g per day (2.4 g or 100 mmol sodium) — this is roughly equivalent to a teaspoonful of salt. The SACN recommendations for children are:
- 0–6 months old: less than 1 g/day
- 7–12 months: 1 g/day
- 1–3 years: 2 g/day
- 4–6 years: 3 g/day
- 7–10 years: 5 g/day
- 11–14 years: 6 g/day
SACN states, "The target salt intakes set for adults and children do not represent ideal or optimum consumption levels, but achievable population goals."
Republic of Ireland: The Food Safety Authority of Ireland endorses the UK targets "emphasising that the RDA of 1.6 g sodium (4 g salt) per day should form the basis of advice targeted at individuals as distinct from the population health target of a mean salt intake of 6 g per day."(, p16)
Canada: Health Canada recommends an Adequate Intake (AI) and an Upper Limit (UL) in terms of
sodium.
- 0–6 months old: 0.12 g/day (AI)
- 7–12 months: 0.37 g/day (AI)
- 1–3 years: 1 g/day (AI) 1.5 g/day (UL)
- 4–8 years: 1.2/day (AI) 1.9 g/day (UL)
- 9–13 years: 1.5 g/day (AI) 2.2 g/day (UL)
- 14–50 years: 1.5 g/day (AI) 2.3 g/day (UL)
- 51–70 years: 1.3 g/day (AI) 2.3 g/day (UL)
- 70 years and older: 1.2 g/day (AI) 2.3 g/day (UL)Health Canada Dietary Reference Intakes (look for Sodium)
New Zealand
- Adequate Intake (AI) 0.46 – 0.92 g sodium = 1.2 – 2.3g salt
- Upper Limit (UL)) 2.3 g sodium = 5.8 g saltAuckland District Health Board Public Health Nutrition Advice (PDF)
Australia: The recommended dietary intake (RDI) is 0.92 g–2.3 g sodium per day (= 2.3 g–5.8 g salt)Better Health Channel (Australia, Victoria) Salt
USA: The Food and Drug Administration itself does not make a recommendationU. S. Food and Drug Administration A Pinch of Controversy Shakes Up Dietary Salt but refers readers to
Dietary Guidelines for Americans 2005. These suggest that US citizens should consume less than 2,300 mg of sodium (= 2.3 g sodium = 5.8 g salt) per day.Department of Health and Human Services (HHS) and the Department of Agriculture (USDA)
Dietary Guidelines for Americans 2005 "Sodium and Potassium"
Labeling
UK: The Food Standards Agency defines the level of salt in foods as follows: "High is more than 1.5g salt per 100g (or 0.6g sodium). Low is 0.3g salt or less per 100g (or 0.1g sodium). If the amount of salt per 100g is in between these figures, then that is a medium level of salt." In the UK, foods produced by some supermarkets and manufacturers have ‘traffic light’ colors on the front of the pack: Red (High), Amber (Medium), or Green (Low). Understanding labels
USA: The FDA
Food Labeling Guide stipulates whether a food can be labelled as "free", "low", or "reduced/less" in respect of sodium. When other health claims are made about a food (e.g. low in fat, calories, etc.), a disclosure statement is required if the food exceeds 480mg of sodium per 'serving.'Food and Drug Administration A Food Labeling Guide--Appendix A
Campaigns
In 2004, Britain's Food Standards Agency started a public health campaign called "Salt - Watch it", which recommends no more than 6g of salt per day; it features a character called Sid the Slug and was criticised by the Salt Manufacturers Association (SMA).Salt Manufacturers Association press release New salt campaign under attack The
Advertising Standards Authority did not uphold the SMA complaint in its adjudication.Advertising Standards Authority Broadcast Advertising Adjudications: 20 April 2005 (PDF). In March 2007, the FSA launched the third phase of their campaign with the slogan "Salt. Is your food full of it?" fronted by comedienne
Jenny Eclair. Salt TV ads
The Menzies Research Institute in Tasmania, Australia, maintains a website Salt Matters dedicated to educating people about the potential problems of a salt-laden diet.
Salt substitutes
Salt intake can be reduced by simply reducing the quantity of salty foods in a diet, without recourse to salt substitutes. Salt substitutes have a taste similar to table salt and contain mostly
potassium chloride, which will increase potassium intake. Excess potassium intake can cause hyperkalemia. Various diseases and medications may decrease the body's excretion of potassium, thereby increasing the risk of hyperkalemia. If you have kidney failure, heart failure or diabetes, seek medical advice before using a salt substitute. A manufacturer, LoSalt, has issued an advisory statementLoSalt Advisory Statement (PDF) that people taking the following prescription drugs should not use a salt substitute: Amiloride,
Triamterene, Dytac,
Spironolactone (Brand name Aldactone), Eplerenone and
Inspra.
Production trends
Salt is produced by evaporation of seawater or brine from other sources, such as brine wells and salt lake (geography)s, and by salt mine
rock salt, called
halite. In 2002, total world production was estimated at 210 million metric tonnes, the top five producers being the United States (40.3 million tonnes), China (32.9), Germany (17.7), India (14.5), and Canada (12.3).Susan R. Feldman. Sodium chloride.
Kirk-Othmer Encyclopedia of Chemical Technology. John Wiley & Sons, Inc. Published online
2005. Note that these figures are not just for table salt but for sodium chloride in general.
See also
References
External links
- Salt production methods and practices
- Salt Institute
- Cook's Thesaurus: Salt (Summary and descriptions of edible salts)
Salt and health
Government bodies
Many other government bodies are listed in the References section above.
- Ireland: Food Safety Authority of Ireland Salt and Health
- UK: Food Standards Agency Salt campaign
- UK: Scientific Advisory Committee on Nutrition (SACN) Salt and Health (PDF) and Salt Subgroup minutes
- UK: Why 6g? A summary of the scientific evidence for the salt intake target
Medical authorities
- The Cochrane Collaboration "Effect of longer-term modest salt reduction on blood pressure"
- Menzies Research Institute Salt Matters Web Site
Charities and campaigns
- British Nutrition Foundation article "Salt in the Diet"
- Consensus Action on Salt and Health (UK charity)
- Action on Salt and Health
- CSPI page Salt: The Forgotten Killer
- Irish Heart Foundation booklet Time to cut down on salt (PDF format)
Journalism
- BBC article "Salt: friend or foe?"
- BBC medical notes "Salt"
- Guardian article The sceptic
- Ockham's Razor Salt matters - talk by Dr Trevor Beard, Menzies Research Institute (ABC Radio National 4th February 2007)
Salt industry
- EuSalt Position papers
- LoSalt (salt substitute manufacturer)
- Salt Manufacturers' Association Salt and health
- Salt Institute Sodium and health
- Bloch, David: Economics of NaCl: Salt made the world go round.
Chemical data
Further reading
- Mark Kurlansky, Salt : A World History (Penguin Books, 2002). ISBN 0802713734.
- Kurlansky, Mark, and S. D. Schindler. The Story of Salt. New York, NY: G.P. Putnam's Sons, 2006. ISBN 0399239987 -- a children's book about salt.
- Laszlo, Pierre. Salt: Grain of Life. Arts and traditions of the table. New York: Columbia University Press, 2001.
- Department of Health, Dietary Reference Values for Food Energy and Nutrients for the UK: Report of the Panel on DRVs of the Committee on the Medical Aspects of Food Policy , The Stationery Office.
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Sea salt is more highly prized than rock salt, which is mined from underground and needs to be further refined for cooking salt and table salt.