New Delhi: The World Health Organisation (WHO), for the first time, has recommended replacing regular table salt with low sodium salt substitutes (LSSS) for normal adults without kidney issues amid growing evidence that lowering blood pressure is crucial to reduce cardiovascular and chronic kidney diseases.
The health body said that eight million deaths are associated with poor diet globally each year, and of these, 1.9 million are attributable to high sodium intake.
The latest recommendations by the WHO’s Department of Nutrition and Food Safety are for adults in the general population, excluding pregnant women and children, or individuals with kidney impairments, or with other circumstances or conditions that might compromise potassium excretion.
In 2012, WHO had issued guidance on limiting salt intake to under five grams per day and sodium intake to below two grams a day to reduce blood pressure and risk of cardiovascular diseases (CVDs). The member states had then agreed on a global target to reduce mean population sodium intake by 30 percent by 2030 for the prevention and control of non-communicable diseases.
But despite the efforts, progress has been slow and the mean global sodium intake remains high—estimated to be 4.3 grams/day (with a range of 2 to 7 grams/day) in 2019, which is more than twice of what WHO recommends. This demands urgent and accelerated action, WHO said.
The recommendations may have considerable implications for India, where the estimated mean daily salt intake is 8 grams per day (ranging between 7 and 11 grams per day)—much higher than the limit suggested by WHO.
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What the new recommendation means for average Indian
Some experts called the recommendation on replacing regular table salt with potassium-enriched, lower-sodium salt substitutes a transformative step toward reducing hypertension and cardiovascular disease globally, including in India.
Dr Vivekanand Jha, executive director of The George Institute for Global Health India, a global health research organisation, said that the new suggestion was evidence-based guidance and had potential to save millions of lives, particularly in countries like India, where sodium intake is high and potassium consumption remains critically low.
Dr Navinath M., senior nephrologist and renal transplant physician at Asian Institute of Nephrology and Urology in Chennai, underlined the importance of the guideline, saying that though patients with chronic illnesses, like hypertension and kidney conditions, are always advised to take lower quantities of salt, even normal individuals need to decrease the sodium intake to reduce risks of cardiovascular conditions.
The largest epidemiological study of various non-communicable diseases—the ICMR-INDIAB national cross-sectional study by the Indian Council of Medical Research (ICMR) and Madras Diabetes Research Organisation—which was released in 2023, had shown that an estimated 315 million Indians, or 35.5 percent of the population in the country, had hypertension.
Hypertension is considered the most important risk factor for cardiovascular, non-communicable diseases as well as overall disease burden in India. Additionally, the prevalence of chronic kidney disease in different regions in the country has been estimated to range from about one to 13 percent.
What’s salt made of
Sodium chloride (NaCl) is the most common form of salt added to food, both by consumers and manufacturers of food. LSSS are alternatives to regular salt, both for discretionary use—as salt added to foods during cooking or eating—and non-discretionary use—as an ingredient present in manufactured foods, and those served at restaurants or other out-of-home settings.
These alternative salts contain less sodium than regular salt, and often include potassium chloride (KCl), with or without other agents, to achieve a flavour similar to regular salt.
The replacement of some of the NaCl with KCl may be beneficial, compared to regular salt, in addition to the sodium-lowering effect, the new guidelines say because WHO recommends increasing potassium intake from food sources to reduce blood pressure and risk of CVDs.
Dr Navinath pointed out that an average Indian consumes more salt than WHO’s recommendation, and most of the non-discretionary salt consumption comes from the intake of processed or packaged foods, pickles, papads and takeaway food.
The latest guidelines by WHO follow a detailed analysis of evidence from the systematic review of 26 randomised controlled trials published between 1986 and 2021, involving 34,961 adults and 92 children using regular salt versus low-sodium salt.
WHO found that in adults, assignment to use LSSS, compared to regular salt, resulted in reductions in diastolic and systolic blood pressure (the two numbers that make up a blood pressure reading) during follow-up periods ranging in length from 56 days to five years.
Also, the use of LSSS, when compared to regular salt, showed reductions in risks of non-fatal stroke, non-fatal acute coronary syndrome and cardiovascular death.
The recommendation, however, has been assessed as conditional because the overall certainty of evidence was low according to the GRADE guidance (a systematic approach to rating the certainty of evidence). Besides, there was uncertainty about the balance between the benefits and potential harms, especially in settings where a considerable proportion of the population may have undiagnosed conditions for which it would not be advisable to increase potassium intakes.
But importantly, LSSS, compared to regular salt, resulted in little to no difference in hyperkalemia, a condition in which potassium level in the blood gets too high, the WHO has also said.
The United Nations health agency has clarified that the recommendation, which applies to LSSS containing KCl, should be considered in the context of other WHO recommendations related to potassium intake.
“WHO recommends consuming foods that naturally contain potassium (such as beans and peas, nuts and green vegetables) as part of a healthy diet. These foods have other nutritional benefits and should be the primary sources of dietary potassium when seeking to increase intake,” the guidelines say.
Dr Nishith Chandra, principal director (interventional cardiology) at Fortis Escorts Heart Institute in Delhi, highlighted that switching to LSSS could have other implications, such as iodine intake.
Universal iodisation of salt has been the preferred strategy for the control of iodine deficiency disorders, such as hypothyroidism and goitre in most countries, including India, for decades.
The new guidelines recognise the problem and say that currently, just under half of the LSSS available globally are iodised, and action is required to ensure their iodisation in order to align with national policies on salt iodisation.
Cost barriers
Dr Navinath highlighted that while many people can benefit from the new WHO guidelines, LSSS are more expensive and their adoption by all might not be easy.
Common table salt, for instance, costs just about Rs 20-40 per kilogram, while the available brands of LSSS in India may cost Rs 150-Rs 200 per kilogram. The price of rock salt, which is considered to contain slightly lesser amount of sodium and used by many in India, is also higher compared to common table salt.
Dr Jha insisted that the country needs to make the low-sodium, potassium-enriched salts affordable and easily available. “By working with policymakers and the food industry, and by educating people about their benefits with clear labelling and subsidies, we can encourage their use, save lives, and tackle India’s high salt intake for a healthier future.”
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