The leading salt substitutes are non-sodium table salts, which have their tastes as a result of compounds other than sodium chloride. Non-sodium salts reduce daily sodium intake and reduce the health effects of this element.
The human minimum requirement for sodium in the diet is about 500 mg per day,[3] which is typically less than one-sixth as much as many diets "seasoned to taste". For certain people with salt-sensitive blood pressure or diseases such as Ménière's disease, this extra intake may cause a negative effect on health.
WHO guidelines[4][5] state that adults should consume less than 2,000 mg of sodium/day (i.e. about 5 grams of traditional table salt), and at least 3,510 mg of potassium per day.[6] In Europe, adults and children consume about twice as much sodium as recommended by experts.[7]
In 2021, a large randomised controlled trial of 20,995 older people in China reported that use of a potassium salt substitute in home cooking over a five-year period reduced the risk of stroke by 14%, major cardiovascular events by 13% and all-cause mortality by 12% compared to use of regular table salt.[8] The study reported no significant difference in hyperkalaemia between the two groups, though people with serious kidney disease were excluded from the trial. The salt substitute used was 25% potassium chloride and 75% sodium chloride.
A 2022 Cochrane review of 26 trials involving salt substitutes reported their use probably slightly reduces blood pressure, non-fatal stroke, non-fatal acute coronary syndrome and heart disease death in adults compared to use of regular table salt.[9] A separate systematic review and meta-analysis published in the same year of 21 trials involving salt substitutes reported protective effects of salt substitute on total mortality, cardiovascular mortality and cardiovascular events.[10]
A 2023 clinical trial engaged 1,612 residents of 48 residential care facilities in China. They were cluster-randomized via a 2 × 2 factorial design substituting 62.5% NaCl/25% KCl versus usual salt and progressively restricted versus usual supply for 2 years. The substitute lowered systolic blood pressure (–7.1 mmHg, 95% confidence interval (CI) –10.5 to –3.8), meeting the primary endpoint, whereas restricted vs usual supply had no effect. Substitute lowered diastolic blood pressure (–1.9 mmHg, 95% CI –3.6 to –0.2) and resulted in fewer cardiovascular events (hazard ratio (HR) 0.60, 95% CI 0.38–0.96), but had no effect on total mortality.[11]
Potassium closely resembles the saltiness of sodium. In practice, potassium chloride (also known as potassium salt) is the most commonly used salt substitute. Its toxicity for a healthy person is approximately equal to that of table salt (the LD50 is about 2.5 g/kg, or approximately 190 g for a person weighing 75 kg). Potassium lactate may also be used to reduce sodium levels in food products and is commonly used in meat and poultry products.[12] The recommended daily allowance of potassium is higher than that for sodium,[13] yet a typical person consumes less potassium than sodium in a given day.[14] Potassium chloride has a bitteraftertaste when used in higher proportions, which consumers may find unpalatable. As a result, some formulations only replace half the sodium chloride with potassium.[15]
Sodium malate is salty in taste and may be blended with other salt substitutes. Although it contains sodium, the mass fraction is lower.[17]
Monosodium glutamate is often used as a substitute for salt in processed and restaurant food, due to its salty taste and low sodium content compared to table salt, and can also be used effectively in home cooking.[18][19]
Seaweed granules are also marketed as alternatives to salt.[20]
Dehydrated, pulverized Salicornia (glasswort, marsh samphire) is sold under the brand name "Green Salt" as a salt substitute claimed to be as salty in taste as table salt, but with less sodium.[21][22]
Even further back in the early 20th century, lithium chloride was used as a salt substitute for those with hypertension. However, overdosing was common and deaths have occurred, leading to its prohibition in 1949.[25]
Salt substitutes can also be further enriched with the essential nutrients. A salt substitute can, analogously to the problem of iodine deficiency, help to eliminate the "hidden hunger" i.e. insufficient supply of necessary micronutrients such as iron.[30][31] Such substances are promoted by UNICEF as a "super-salt".[32]
^Drake, S. L.; Drake, M. A. (2011). "Comparison of Salty Taste and Time Intensity of Sea and Land Salts from Around the World". Journal of Sensory Studies. 26 (1): 25–34. doi:10.1111/j.1745-459X.2010.00317.x. ISSN1745-459X.
^Florence Fabricant, "To Sprinkle: Add Some Green To Your Salt Lineup", New York Times, August 11, 2021, p. D3; online version "Add Green to Your Salt Lineup" August 9, 2021
^Marmol, F. (2008). "Lithium: Bipolar disorder and neurodegenerative diseases Possible cellular mechanisms of the therapeutic effects of lithium". Progress in Neuro-Psychopharmacology and Biological Psychiatry. 32 (8): 1761–1771. doi:10.1016/j.pnpbp.2008.08.012. PMID18789369. S2CID25861243.
^Huynh, Hue Linh; Danhi, Robert; Yan, See Wan (27 November 2015). "Using Fish Sauce as a Substitute for Sodium Chloride in Culinary Sauces and Effects on Sensory Properties". Journal of Food Science. 81 (1): S150–S155. doi:10.1111/1750-3841.13171. PMID26613570.