For taste, not health: sodium gaps in drinking water

Is it possible to “oversalt” not food, but water? A new review in Nutrients analyzed national drinking water standards in 197 countries and came to an inconvenient conclusion: in most cases, sodium limits are set not for health, but for taste, and they are guided by the WHO recommendation of 200 mg / l - the “threshold of pleasantness”, not safety. In practice, this means that when consuming 2 liters of such water, a person receives about 400 mg of sodium - about 20% of the upper daily limit for adults. Against the background of climate change and salinization of sources, this is an underestimated contribution to hypertension and cardiovascular risks, the authors warn.

Background of the study

Sodium is a key driver of hypertension and cardiovascular mortality. Almost all prevention efforts focus on salt in food, although water can also contribute significantly to the diet, especially where freshwater sources are becoming saline. Drinking 2 liters of water with a sodium content of 200 mg/L (a common standard) would provide about 400 mg of sodium per day - about 1 g of table salt and up to 20% of the upper recommended daily limit for adults. For people with severe restrictions (heart/kidney failure, resistant hypertension, formula-fed infants), even such supplements can be clinically significant.

The sources of "salt water" are multiplying: seawater intrusion into coastal aquifers, droughts and desalination with incomplete purification of concentrates, irrigation and drainage of agriculture, road reagents, depletion and mineralization of groundwater. Against the backdrop of climate change, the trend towards salinization is increasing, while regulation is lagging behind: international and national drinking water quality standards often set sodium thresholds based on organoleptics ("tasty/not tasty"), rather than health risks. The classic benchmark of 200 mg/l from WHO recommendations historically reflects the threshold of pleasantness, rather than a medically justified safety limit.

The picture is exacerbated by inequalities in access: in low- and middle-income countries, sodium monitoring in centralized systems and private wells is irregular, limits are nonexistent or advisory, and the population is often not informed about the sodium content of water. Even in wealthy regions, standards rarely take into account vulnerable groups and total exposure (water + food), although it is this that affects blood pressure and cardiovascular risk.

The scientific and practical gaps are as follows: (1) there are no health-dependent global thresholds for sodium in drinking-water; (2) the contribution of water to daily sodium in different climatic and geographical scenarios is poorly taken into account; (3) the needs of patients on sodium-restricted diets are underestimated. Therefore, a systemic review of national standards and regulatory practices is needed to: a) show the scale of inconsistency; b) assess where thresholds are formed “by taste” and where - by health; c) outline the updating of recommendations (including stricter benchmarks for vulnerable groups), transparent monitoring and informing the population. This is a direct intersection of SDG 6 (clean water and sanitation) and SDG 3 (health and well-being) in the era of climate change.

What exactly were you looking for and how?

• A desk review of current documents (laws, standards, guidelines) on drinking water quality was conducted from September 2024 to May 2025; the list from the 2021 WHO review served as a reference. For documents not available online, data from the authors of that review were used.
• We compared: is there a sodium limit, is it mandatory or recommended, what is the level (minimum/maximum/“target”), and what is its justification - aesthetics (taste/organoleptics) or health.

The bottom line is that there are a few hard-to-ignore facts. First, the WHO does not set a health-based sodium limit in its drinking-water guidelines (the latest version is from 2017), offering only a “pleasantness threshold” of 200 mg/L. Second, one-fifth of countries have no sodium limit at all; of those that do, 92% simply copy 200 mg/L. Third, even the “taste” threshold may be too high: An analysis by the U.S. Environmental Protection Agency (EPA) suggests 30–60 mg/L is a more realistic range for water to remain palatable to most people.

Key Results - Numbers and Geography

• Of the 132 countries with a limit, 121 (92%) set a WHO-style target/limit of 200 mg/L (worldwide range: 50-400 mg/L). 8 countries (5%) are stricter than 200 mg/L (e.g. Barbados 50 mg/L, Qatar 80 mg/L). 6 countries (4%) allow levels above 200 mg/L (up to 400 mg/L), sometimes leaving the “target” level ≤200 mg/L.
• Europe is almost entirely "under the EU standard" of 200 mg/l (mandatory for 98% of countries in the region). The largest share of countries without a limit are Asia (33%) and America (26%).
• By income: among high-income people, 71% have 200 mg/l; among lower-middle-income people, a quarter of countries have no limit at all (25%).
• Only three countries (Australia, Canada, USA) specifically recommend <20 mg/L for people with severe sodium restriction (eg, severe hypertension, HF).
• As for the rationale: almost half of the documents call sodium an “indicator/physicochemical parameter”, 29% refer to taste/organoleptic properties; only 9-10% directly indicate health considerations.

Why does this matter now? Because freshwater salinization is not an abstraction. Sea level rise, droughts, and agriculture are increasing the salinity of water sources, especially in coastal Asia and arid Africa, yet data on the scale of exposure and impacts are still scant. When sodium in the tap water in Walgett, Australia, exceeded 300 mg/L in 2019, the lack of a health-based limit prevented a quick push for improved water quality—local groups are still calling for revised guidelines.

What do examples of "strict" countries say?

• Barbados (50 mg/L limit) built the largest brackish water desalination plant in the Caribbean, which now supplies about 30% of the population - thus protecting the country from droughts and at the same time tightening the standard.
• Qatar (limit 80 mg/l) closes half of its water supply with desalination and also declares the balance of health + taste as the basis for the strict level.
• Sweden and the Netherlands went below the pan-European 200 mg/l, “insurance” against the climate scenario of salinization and a possible “surge in hypertension”.

Key findings of the review

• Policy gap: Global sodium standards are largely about “taste” rather than health. They are inconsistent with the goal of reducing premature deaths from NCDs and ignore the contribution of water to total sodium in specific communities.
• Inequality of access: Low-income countries are more affected by salinization, but are less likely to have the limits and resources to control/desalinize. There, the “salt in the water” can add significantly to already high dietary sodium.
• Even "by taste" 200 mg/L is too much: EPA data points to 30-60 mg/L as a reasonable threshold for most, which would also reduce the water's contribution to the daily value to <6% of the WHO limit.

What to do? The authors propose a multi-level agenda. First, review WHO recommendations and EU standards, setting a clear health-dependent limit for sodium (and not just “palatability”). Second, introduce mandatory information to the population about the salinity of local water and transparent monitoring. Third, help countries with a high risk of salinization with infrastructure (desalination, mixing of sources), financing and training.

Practical implications for the health care system

• Consider the contribution of water to sodium in patients with hypertension, CHF, kidney disease - especially in coastal and arid regions.
• Use <20 mg/L as a guideline for "strict" sodium-restricted diets (as Australia, Canada, USA already do).
• Support research and audit: actual sodium levels in tap/bottled water, proportion of population with exposure >30-60 mg/L, association with BP and events.

Conclusion

Our standards for "taste" do not protect "health". If water brings hundreds of milligrams of sodium per day to millions of people, it is time to restructure the regulation - from palatability to health, with an eye on climate risks and the rise of NCDs.

Source: Crowther J. et al. Global Drinking Water Standards Lack Clear Health-Based Limits for Sodium. Nutrients 2025;17:2190. https://doi.org/10.3390/nu17132190