The chemical name of the common salt is Sodium Chloride (NaCl). Sodium Chloride contains 39% of sodium, an element which never occurs in free form in nature. It is found associated with many minerals especially in plentiful amounts with chlorine.
Sodium chloride when dissolved in water yields sodium in the body and found in extracellular fluids. Sodium ions make up 93% of the basic ions in the blood. Common salt is obtained mainly from sea water. To recover common salt, sea water is run into lagoons and allowed to evaporate (A lagoon is a shallow salt water lake separated from the sea by sand banks). The sun’s heat evaporates water and crude common salt is left behind.
Sodium chloride is highly soluble in water. When common salt is kept open, it absorbs moisture from the air due to the presence of small amount of magnesium chloride in it. Magnesium chloride (MgCl2) is a deliquescent salt which absorbs moisture from the air to form a solution.
Requirement of salt in the body
Some amount of salt is definitely required by the body because of the following functions it serves in the body:
i. NaCl is an important constituent of our blood (0.9 gm in every 100 ml). It is important for the maintenance of Red Blood cells and helps proteins to dissolve.
ii. Sodium ions help in the conduction of nerve impulses and contraction of muscles.
iii. Sodium ions help to retain water in the body and maintain water balance.
iv. Sodium ions are important in transport of substances across cell membranes.
v. Sodium ions play a part in the electrical activity of the heart. Exchange of sodium and potassium ions in the pacemaker cells of the heart’s sinoatrial node causes the heart to beat.
vi. Chloride ions are an important component of blood plasma.
vii. Chloride ions help in formation of HC1 (Hydrochloric acid) in stomach for digestion.
viii. A saline drip is given to patients suffering from a severe loss of salts from the body as in cholera, dysentery, vomiting etc.
ix. Sodium plays an important role in the regulation of acid base balance in the body fluids including blood, lymph, tears and gastrointestinal secretions.
Experts suggest a maximum salt intake of 5 gm. per day for an adult without a family history of blood pressure. If there is a family history then salt may be reduced to 2 gm. per day.
However, increased salt intake is warranted during hot summer days and periods of heavy exertion that cause profuse sweating since salt and water are lost when we perspire or sweat. The white spots left on our coloured clothes by the drying sweat during summer are because of sodium chloride deposition. This is because when sweat dries from the clothes, water in it evaporates leaving behind sodium chloride which produces white spots on the clothes.
Severe salt loss in the body manifests muscle cramps, irritability and apathy.
Harmful effects of excess salt on body
i. Salt is a stimulant: It is stimulant. It stimulates Sympathetic Nervous System and adrenal glands and creates stress arousal. That’s why it comes under the category of stress food.
ii. High blood pressure: Excessive salt causes water retention in the body and increases the blood volume and cardiac output resulting into High Blood Pressure. Considerable fall in B.P. is observed with reduction in dietary salt intake in Hypertension.
iii. Weakening of bones: Eating too much salt can pull calcium from the bones making them weak More calcium is also excreted in the urine with the ingestion of more table salt.
iv. Effect on Kidneys: Excess salt puts a heavy burden on kidneys because they have to work harder to remove the excess salt. Hence they may gradually weaken. Kidneys can’t remove more than 4-5 gm of salt per day. Remaining salt not able to be excreted gives rise to undesirable ailments in the body.
v. Increase in weight: Excess salt in the body increases the weight of the body because of the following reason. Kidneys eliminate excess salt from the body by filtering out the sodium that makes up part of the salt compound. In case kidneys work less efficiently either because they have gone weak or because of lowered blood supply to them (because of weak heart), the kidneys excrete sodium less efficiently and more sodium is retained in the body. Since the kidneys are geared to maintain a fixed proportion of sodium to water in the blood, excess salt in the body means excess water too and hence excess weight of the body.
vi. Worsening of Oedema: Salt makes oedema worse and should be avoided in all oedematous states whether due to liver, kidney or endocrine diseases.
vii. Hardening of arteries: Table salt is not completely soluble in water and tends to harden the arteries by its excessive use. For good health, that salt is required which is entirely soluble in water. High temperatures used for making table salt and elements like potassium chloride and sulphate and other chlorides tend to inhibit the dissolving of salt in water.
viii. Salt increases uric acid: Excess of salt interferes with the elimination of certain wastes of the system like uric acid and therefore contributes indirectly to various diseases like gout etc.
ix. Bronchial and Lung problems: Deficiency of organic sodium in table salt results in bronchial and lung problems because organic sodium is required for the elimination of CO2 from the system.
Natural foods also contain salt
Actually speaking, there is some salt present in every natural food we eat which is enough to meet the needs of the body under normal circumstances.
Sodium Content of Different Foods (mg. per 100 gram)
Hence one has to calculate his sodium intake taking into account the above sodium contents present in natural foods.
Common eatables (processed/cooked foods) containing table salt
We are consuming table salt in various processed foods (in addition to salt consumed from natural foods as described earlier) such as (i) soft drinks (ii) sauce, ketchups (iii) cornflakes (iv) salted biscuits (v) processed cheese (vi) butter milk, lassi (Mamkeen), (vii) raita (viii) salad with salt sprinkled over it (ix) pickles (x) tinned and canned vegetables/fruits (xi) papads (xii) potato chips (xiii) roasted badam, kashewnuts, peanuts (xiv) pasta (xv) cooked vegetables and dais (xvi) sandwitches, pizzas (xvii) Chinese foods (xviii) chutney (xix) soup (xx) pakoras, patties, samosas (xxi) salted butter.
Please also remember that there are other forms of sodium also than those found in table salt. Sodium nitrate is used to preserve many processed foods. Scientists have discovered that sodium nitrate can cause cancerous tumors if ingested over a period of years. Another way to obtain sodium is through monosodium glutamate commonly known as MSG. It is commonly found in Chinese foods as well as canned, frozen and packaged foods. MSG is used to enhance flavour. Although it tastes less salty than table salt, it has three times the sodium content.
Recommendations/better substitutes for table salt
- Table salt is an inorganic material and a strongly ionic bonded material and resists being separated into the sodium and chloride ions that are usable by body. Hence it doesn’t replenish properly the sodium needed for our body. While the salt in fruits and vegetables is organic in nature and loosely covalently bonded and can be easily utilized by body. Hence we should try to reduce the intake of table salt and suffice our requirement by intake of natural foods. Infact whatever amount of salt is needed by body is already provided by the natural foods we take daily.
- Rock salt is considered better than table salt. Rock salt deposits are found in some mountainous regions. Salt is dug out from the rock salt deposits. It exists dissolved in water if found very deep. The saturated solution is then pumped out and evaporated to get the salt. Rock salt has been found to be entirely soluble in water and the body enzymes can make good use of it thereof.
- Black salt (Kala Namak) is also considered better than ordinary table salt because it (black salt) is organic in nature.
- For High B.P. patients, potassium salt is recommended than sodium salt. Such salts are now a days available in the market with the brand names ‘Annapurna salt’, ‘Lona salt’ (ayurvedic), ‘Saffola salt’ etc.