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Edible salt

2007 Schools Wikipedia Selection. Related subjects: Chemical compounds;
Health and medicine

   Edible salt is mostly sodium chloride (NaCl). This salt shaker also
   contains grains of rice, which absorb moisture and prevent the salt
   from caking
   Enlarge
   Edible salt is mostly sodium chloride (NaCl). This salt shaker also
   contains grains of rice, which absorb moisture and prevent the salt
   from caking
   Salt well brine being boiled down to pure salt in Zigong, China
   Enlarge
   Salt well brine being boiled down to pure salt in Zigong, China
   Mounds of salt
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   Mounds of salt
   Salt rocks
   Enlarge
   Salt rocks

   Edible salt, also called table salt or just salt, is a mineral, one of
   a very few rocks commonly eaten by humans. There are different forms of
   edible salt: unrefined salt, refined salt, table salt or iodised salt.
   It is a crystalline solid, white, pale pink or light grey in colour,
   obtained from sea water or from rock deposits. Sea salt comes in fine
   or larger crystals. In nature, it includes not only sodium chloride,
   but also other vital trace minerals. Edible rock salts may be slightly
   greyish in colour due to this mineral content.

   Salt is necessary for the survival of all living creatures, including
   humans. 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.

   Salt is required for life, but overconsumption can increase the risk of
   health problems, including high blood pressure, in those individuals
   who are genetically predisposed to hypertension. In food preparation,
   salt is used as a preservative and as a seasoning.

History of edible salt

   Salt's preservative ability was a foundation of civilization. It
   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.

   In the empire of Mali, 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 exporting the salt.

Forms of edible salt

Unrefined salt

   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.
   There are concerns, however, that raw sea or rock salts may not contain
   sufficient iodine salts to prevent iodine deficiency diseases like
   goitre.

Refined salt

   Refined salt, that is most widely used presently, is mainly sodium
   chloride. Only about 7% of refined salt is used as a food additive. The
   majority is sold for industrial use, from manufacturing pulp and paper
   to setting dyes in textiles and fabric, to producing soaps and
   detergents, and has great commercial value.

   The manufacture and use of salt is one of the oldest chemical
   industries. Salt is also obtained by evaporation of sea water, usually
   in shallow basins warmed by sunlight; 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
   edible salt. These rock salt deposits were formed by the evaporation of
   ancient salt lakes. These deposits may be mined 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). Multiple stages of evaporation are then used to collect
   pure sodium chloride crystals, which are kiln-dried.

   Anticaking agents (and potassium iodide, for iodised salt) are
   generally added at this point. These agents are hygroscopic chemicals
   which absorb humidity, keeping the salt crystals from sticking
   together. Some anticaking agents used are tricalcium phosphate, calcium
   or magnesium carbonates, fatty acid salts ( acid salts), magnesium
   oxide, silicon dioxide, 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 in regulated quantities. The refined salt is then
   ready for packing and distribution.

Table salt

   Single-serving salt packets
   Enlarge
   Single-serving salt packets

   Table salt is refined salt, nearly pure (95% or greater) sodium
   chloride. It usually contains substances that make it free flowing
   (anticaking agents) such as sodium silicoaluminate as well as a minute
   amount of invert sugar to prevent the salt from turning a yellow colour
   when exposed to sunlight, and to prevent a significant loss of iodine
   via vaporization. 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. Table salt is also often iodised—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. Iodised table salt has significantly
   reduced disorders of iodine deficiency in countries where it is used.
   Iodine is important to prevent the insufficient production of thyroid
   hormones ( hypothyroidism), which can cause goitre, cretinism in
   children, and myxedema in adults.

   Table salt is now used all over the world.

   In European countries where fluoridation of drinking water is not
   practiced, some brands of fluorinated and iodised table salt are
   available. In Germany, 60% of sold table salt contains sodium or
   potassium fluoride. Another additive, especially important for pregnant
   women is Folic acid (B vitamin) giving the table salt a yellow colour.

Health effects

   Sodium is one of the primary electrolytes in the body. All three
   electrolytes (sodium, potassium, 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 muscle
   cramps, dizziness, or even an electrolyte disturbance, which can cause
   severe, even fatal, neurological problems. Drinking too much water,
   with insufficient salt intake, puts a person at risk of water
   intoxication. Salt is even sometimes used as a health aid, such as in
   treatment of dysautonomia.

   People's risk for disease due to salt intake that is too low or too
   high varies, due to biochemical individuality. In fact, some have
   asserted that while the risks of consuming too much salt are real, the
   risks have been dramatically overhyped for most people, or that the
   studies done on the consumption of edible salt can be interpeted in
   many different ways.

   Salt consumption has been linked to:
     * exercise-induced asthma. 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…".
     * heartburn.
     * osteoporosis: One report shows that a high salt diet does reduce
       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." (, 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)
     * 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). "The CMO
       [Chief Medical Officer] of England, in his Annual Report (DH,
       2001), highlighted that people with high blood pressure are three
       times more likely to develop heart disease and stroke, and twice as
       likely to die from these diseases than those with normal levels."(,
       p14). Professor Dr. Diederick Grobbee claims that there is no
       evidence of a causal link between salt intake and mortality or
       cardiovascular events.. One study found that low urinary sodium is
       associated with greater risk of myocardial infarction among treated
       hypertensive men .
     * 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." (,
       p12) Excessive salt (sodium) intake, combined with an inadequate
       intake of water, can cause hypernatremia. It can exacerbate renal
       disease.
     * edema (BE: oedema): A decrease in salt intake has been suggested to
       treat edema (BE: oedema) (fluid retention).

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 6g a day" but for a person is 4g.

   Intakes can be expressed variously as salt or sodium and in various
   units.
     * 1g sodium = 1,000mg sodium = 42 mmol sodium = 2.5g salt

   United Kingdom: In 2003, the UK's Scientific Advisory Committee on
   Nutrition (SACN) recommended that, for a typical adult, the Reference
   Nutrient Intake (the amount you need) is 4g salt per day (1.6g 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 6g per day (2.4g 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 1g/day
     * 7–12 months: 1g/day
     * 1–3 years: 2g/day
     * 4–6 years: 3g/day
     * 7–10 years: 5g/day
     * 11–14 years: 6g/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 1.6g sodium (4g 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 6g per
   day."(, p16)

   Canada: Health Canada recommends an Adequate Intake (AI) and an Upper
   Limit (UL) in terms of sodium.
     * 0–6 months old: 0.12g/day (AI)
     * 7–12 months: 0.37g/day (AI)
     * 1–3 years: 1g/day (AI) 1.5g/day (UL)
     * 4–8 years: 1.2/day (AI) 1.9g/day (UL)
     * 9–13 years: 1.5g/day (AI) 2.2g/day (UL)
     * 14–50 years: 1.5g/day (AI) 2.3g/day (UL)
     * 51–70 years: 1.3g/day (AI) 2.3g/day (UL)
     * 70 years and older: 1.2g/day (AI) 2.3g/day (UL)

   New Zealand
     * Adequate Intake (AI) 0.46 – 0.92g sodium = 1.2 – 2.3g salt
     * Upper Limit (UL)) 2.3g sodium = 5.8g salt

   Australia: The recommended dietary intake (RDI) is 0.92g–2.3g sodium
   per day (= 2.3g–5.8g salt)

   USA: The Food and Drug Administration itself does not make a
   recommendation but refers readers to Dietary Guidelines for Americans
   2005. These suggest that US citizens should consume less than 2,300 mg
   of sodium (= 2.3g sodium = 5.8g salt) per day.

Labeling

   The FDA Food Labeling Guide stipulates whether a food can be labelled
   as "free", "low", or "reduced/less" in respect of sodium. A food that
   exceeds 480mg of sodium per 'serving' must have a disclosure statement.

Campaigns

   In 2004, the 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). The Advertising Standards
   Authority did not uphold the SMA complaint in its adjudication..

Salt substitutes

   Salt intake can be reduced quite easily by simply reducing salty foods
   in one's diet. Salt substitutes have a taste similar to table salt and
   contain mostly potassium chloride, which will increase potassium
   intake. Because excess potassium intake can cause potentially fatal
   hyperkalemia, it is advisable to check with one's physician and
   pharmacist before using salt substitutes. 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 have diabetes, you should not use a low salt variety without
   medical advice. A manufacturer, LoSalt, has issued an advisory
   statement. that people taking the following prescription drugs should
   not use a salt substitute: Amiloride, Triamterene, Dytac,
   Spironolactone, Aldactone, Eplerenone, and Inspra.

   Retrieved from " http://en.wikipedia.org/wiki/Edible_salt"
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   with only minor checks and changes (see www.wikipedia.org for details
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