Salt substitutes look safe for most adults. In a trial of 20,995 high-risk people, they cut strokes by 14% and deaths by 12% (Trial). Serious potassium problems were about as rare as on regular salt. The big exception is kidney disease or a drug that raises potassium. If either applies to you, ask your doctor first.
That stroke result is rare in nutrition science. Most diet advice rests on studies that watch what people eat and then guess at cause. This trial was different: a coin flip decided which villages got the new salt. Then researchers counted strokes and deaths for almost five years.
What Salt Substitutes Are
A salt substitute swaps some or all of the sodium chloride in table salt for potassium chloride. Potassium chloride looks and tastes salty. Some people find it a little bitter on its own, and many products blend it with regular salt.
The blends differ a lot. The big stroke trial used 75% sodium chloride and 25% potassium chloride (Trial). A 25% blend like that carries about 131 mg of potassium per gram, though brands vary slightly (Study). “Lite” salts go further. Morton Lite Salt, a common US brand, is half sodium chloride and half potassium chloride. That gives it half the sodium of regular salt (Product page).
Some products skip the sodium chloride and use potassium chloride as the base. One of them, NoSalt, has 650 mg of potassium in a quarter teaspoon (Study). For scale, the National Academies set an adequate potassium intake of 3,400 mg a day for men and 2,600 mg for women (Report). So a quarter teaspoon of NoSalt gives a woman about a quarter of her daily need.
Most Americans get too little potassium and too much sodium. Men average about 3,000 mg of potassium a day, and women about 2,300 mg (Guidance). Sodium averages 3,400 mg a day, against a limit of 2,300 mg. Since 2020, the FDA has not objected when labels call potassium chloride “potassium salt.”
The swap does two jobs at once. Sodium tends to raise blood pressure. Potassium helps the kidneys flush out sodium, and it helps blood vessels relax. The trials also hint that the dose matters: blends with less sodium chloride were linked to bigger drops in blood pressure (Meta-analysis).
The Trial That Counted Strokes
The main study is the Salt Substitute and Stroke Study, or SSaSS, published in 2021. It enrolled 20,995 people in 600 villages in rural northern China (Trial). Everyone had either had a stroke before or was 60 or older with high blood pressure. Their average age was 65, and 73 in every 100 had already had a stroke.
A coin flip decided which villages switched to the 75/25 blend and which kept regular salt. Whole villages were assigned together, so everyone in a village was in the same group. People knew which salt they were using. The team then followed everyone for about 4.7 years.
The team counted events per 1,000 people per year. Strokes ran at 29.1 on the substitute against 33.7 on regular salt, about 14% fewer. They also tracked major heart and blood vessel events, a count that includes strokes and heart attacks. Those ran at 49.1 against 56.3, or 13% fewer. Deaths from any cause fell from 44.6 to 39.3, or 12% fewer (Trial).
The safety worry with potassium is hyperkalemia, meaning too much potassium in the blood. It can upset the heart’s rhythm. In SSaSS, serious problems blamed on high potassium were about as rare on the substitute as on regular salt. Both groups had roughly 3.3 per 1,000 people a year (Trial). But the trial left out any household where someone had serious kidney problems or took potassium-sparing diuretics or potassium supplements (Trial registry).
In 2025, the team took a closer look at the 15,249 people who had already had a stroke (Trial). Over roughly five years, 17 in every 100 on the substitute had another stroke, against 19 in every 100 on regular salt. That works out to about 14% fewer repeat strokes. Deaths fell too, from 22 in every 100 to 20 in every 100, or 12% fewer. The authors planned this analysis in advance but still call it exploratory, so treat it as a first look rather than proof.
Strokes caused by bleeding in the brain dropped the most, by 30%, and fatal strokes fell by 21%. Strokes caused by a blocked artery were the most common type here, and they fell too little to rule out chance. High-potassium events were again about the same in both groups. But SSaSS never ran repeat blood potassium tests, so mild rises could have gone unseen (Review).
How Much Blood Pressure Drops
Most of the other trials measured blood pressure. A 2022 analysis pooled 21 trials with 31,949 people (Meta-analysis). On average, salt substitutes lowered the top number, systolic pressure, by 4.6 points. The bottom number, diastolic pressure, fell by 1.6 points. Points here are mmHg, the unit your blood pressure cuff shows.
That drop held across regions, ages, sexes and starting blood pressure. Dose may matter too, though that link was borderline. Each 10% less sodium chloride in the blend went with about 1.5 more points off the top number. The same review found 11% fewer deaths overall, and 13% fewer deaths from heart and blood vessel disease. One caveat: several of its authors also ran SSaSS, and that one trial supplies most of the death data.
A Cochrane review, the one WHO commissioned for its guideline, came to the same conclusion. It covered 26 trials and nearly 35,000 adults. In the trials that measured it, salt substitutes probably lowered the top number by 4.8 points and the bottom number by 2.4 (Review). Cochrane rated this moderate certainty: the drop is likely real, but small. Deaths from heart and blood vessel disease probably fell by about 180 per 100,000 people a year, though chance can’t be fully ruled out. Non-fatal strokes fell by 20 per 100,000, a drop small enough that chance could explain it.
What do 4 or 5 points mean for you? On their own, they won’t move most people from high blood pressure to normal. Across thousands of people, though, small drops add up. In SSaSS, that showed up as fewer strokes and deaths.
Other trials found the effect in very different settings. In DECIDE-Salt, a coin flip decided which of 48 elder-care homes in China would cook with the substitute. The 1,612 residents, all aged 55 and up, were followed for two years (Trial). The kitchens used a blend of 62.5% sodium chloride and 25% potassium chloride. The top number fell 7 points, and heart and blood vessel events fell by about 40%. Deaths showed no clear change. Blood potassium rose, and lab tests caught high potassium more often, but this was not linked to harm. The salt maker supplied both salts free of charge.
A common worry is that blood pressure might drop too low in older people. A later look at 611 of those residents, all with normal blood pressure at the start, found no sign of it. Episodes of low blood pressure were about the same: 9.0 against 9.7 per 100 people a year (Study). New cases of high blood pressure ran at 11.7 per 100 people a year on the substitute, against 24.3 on regular salt. This was an after-the-fact analysis, so the authors say only that the substitute may lower that risk.
In six villages in Tumbes, Peru, households had their regular salt swapped for a 75/25 blend (Trial). Across all 2,376 adults, the top number fell only slightly, by 1.3 points. Among people who started with normal blood pressure, though, new cases of high blood pressure were about half as common.
Are Salt Substitutes Safe for You?
For some people, a potassium salt can push blood potassium to dangerous levels. Ask a doctor before you switch if any of these apply to you.
- You have kidney disease, or a doctor has said your kidney function is low.
- You take a potassium-sparing diuretic (a type of water pill), such as spironolactone.
- You take an ACE inhibitor, such as lisinopril, or an ARB, such as losartan.
- You take potassium supplements.
Your kidneys remove extra potassium from the blood. When they work less well, potassium can build up. Potassium-sparing diuretics hold on to potassium by design. ACE inhibitors and ARBs block a hormone system that helps the kidneys get rid of potassium. A review of case reports calls kidney problems and these drugs “notorious” for causing high potassium (Review).
The reassuring trial results do not cover these groups. All 26 trials in the Cochrane review left out people known to be at risk from extra potassium (Review). The review’s examples include people with kidney disease, diabetes or potassium-sparing medicines. SSaSS did not exclude ACE inhibitors or ARBs by name, and 23 in every 100 people took one at the start. But it screened out serious kidney disease and never checked blood potassium routinely (Review). So it cannot tell you how these drugs and a potassium salt combine if your kidneys are weak.
A review of 35 case reports found 44 episodes of high potassium caused by diet. Salt substitutes caused 12 of them (Review). Case reports show what can happen, not how often it happens. Most of the patients who got a heart tracing (an ECG) had abnormal results. Three people died, and none of the three had kidney problems.
In one case, a 72-year-old woman used a potassium chloride salt substitute for about six months. She took 3 to 4 teaspoons a day (Study). Her kidney function had been normal. She also took an ACE inhibitor and a beta blocker, and she had diabetes. The shaker alone gave her more potassium than a typical Western diet supplies in a whole day. Her blood potassium rose to life-threatening levels.
The risk shows up across whole populations, too. A 2020 model of a China-wide switch estimated about 11,000 extra deaths a year from high potassium among people with kidney disease (Study). The same model still found far more lives saved overall, even in that group. But a model is an estimate, not a count. Your own blood test tells you more than any average.
WHO draws the same line. Its 2025 guideline leaves out people with kidney problems or anything else that makes it hard to clear potassium (Guideline). Its examples are potassium-sparing diuretics and potassium supplements. It also says not to cook a shared family meal with a substitute if anyone at the table is at risk.
There is almost no evidence for pregnancy or childhood either. No trial has tested salt substitutes in pregnant women, and only one small trial, of 92 children, exists (Review). WHO’s advice does not cover either group (Guideline).
Where the Evidence Stops
The trials cover a narrower group than it first seems. Most of the people in them were older, at high risk, and living in rural China or Peru. A 2026 review pooled 34 trials from 15 countries, half of them in China (Meta-analysis). Salt substitutes lowered the top number by about 4 to 5 points. But the drop in deaths rested mostly on SSaSS, and no trial outside China reported deaths at all.
A 2024 review of long-term trials agreed (Meta-analysis). Seven of the eight trials that reported the main outcomes ran in China or Taiwan. The authors rated the evidence on deaths as low certainty, which is to say weak. They also warned that the results may not carry over well to other groups, especially Western ones.
A second limit is bigger. A shaker swap only replaces the salt you add yourself. In China, more than half of daily salt comes from home cooking and the table (Review). In the US, UK, Canada and Australia, that share is under a quarter. The review’s authors suggest substitutes may help most where people add a lot of salt at home.
A study of 450 adults in three US cities tracked where their sodium came from (Study). About 71% came from food prepared outside the home, such as packaged and restaurant food. About 14% was already in the food naturally. Salt added in home cooking supplied 6%, and salt at the table 5%. Together that is roughly 11%, and it is the only slice a shaker swap can touch.
An older Philadelphia study of 62 regular salt-shaker users found much the same. Table and cooking salt gave them only about 11% of their sodium (Study).
WHO’s January 2025 guideline reflects these limits. It repeats WHO’s long-standing strong advice to keep sodium under 2 g a day (Guideline). Then it adds a softer suggestion: if you use table salt, swap it for a lower-sodium substitute that contains potassium. WHO calls this a conditional recommendation because the evidence is low certainty. It also flags the risk in places where many people may have kidney disease without knowing it (Guideline). The advice covers table salt only, not salt in packaged or restaurant food.
So what if you are 35, healthy and eat a typical Western diet? If your kidneys are fine and you take none of the drugs above, the swap is probably safe. Among the screened people in the trials, serious high-potassium problems were no more common on the substitute (Review). But you will likely gain little, because the shaker supplies little of your sodium. The strong stroke results come from older, high-risk people who added most of their salt at home.
Frequently Asked Questions
Who Should Not Use Salt Substitute?
People with kidney disease should not use one without a doctor’s approval. Neither should people on potassium-sparing diuretics or potassium supplements (Guideline). Ask first, too, if you take an ACE inhibitor, an ARB or spironolactone, since these can raise blood potassium. WHO’s advice also leaves out pregnant women and children, because there is almost no evidence for them.
Is Salt Substitute OK for Kidney Disease?
Not without your doctor’s input. Weak kidneys clear potassium poorly. Every trial in the Cochrane review left out people at risk from extra potassium, such as those with kidney disease (Review). A China-wide model estimated about 11,000 extra deaths a year from high potassium in this group (Study). Ask your doctor to check your potassium first.
Does Salt Substitute Lower Blood Pressure?
Yes, modestly. Across 21 trials, it lowered the top number by 4.6 points and the bottom number by 1.6 points on average (Meta-analysis). In Chinese elder-care homes, the top number dropped by 7 points (Trial).
Is Salt Substitute Safe for Heart Patients?
For many, it may help. In SSaSS, high-risk adults on the substitute had 13% fewer major heart and blood vessel events, such as strokes and heart attacks (Trial). But many heart patients take drugs that raise potassium. These include spironolactone for heart failure, ACE inhibitors and ARBs. If you take any of these, ask your cardiologist before switching.
Key Takeaways
- Fewer strokes and deaths. Among 20,995 high-risk adults in SSaSS, the switch brought about 14% fewer strokes and 12% fewer deaths over 4.7 years (Trial).
- Stroke survivors gained too. Among 15,249 people with a past stroke, repeat strokes fell about 14% and deaths about 12% (Trial).
- A modest blood pressure drop. Across 21 trials, the top number fell 4.6 points on average (Meta-analysis).
- Kidneys and medicines come first. Kidney disease and drugs like spironolactone, ACE inhibitors and ARBs can push potassium too high. Ask a doctor before switching (Review).
- The shaker is a small slice in the West. In one US study, about 71% of sodium came from food prepared outside the home. Only about 11% came from home cooking and the table (Study).
- WHO gives a cautious yes. It suggests the swap for adults who use table salt, but not for people with kidney problems, pregnant women or children (Guideline).
Swap the Shaker, Ask First
Few health changes are this cheap or this easy: you replace one jar in the kitchen. The best trial behind it counted strokes and deaths, not just readings on a cuff. For older adults at high risk, that is unusually strong evidence.
Start with a quick check. Ask your doctor or pharmacist whether your kidneys or your medicines make extra potassium a problem. If you get the all-clear, a blend like the 75/25 trial salt is closest to what was tested. Then cut back on packaged and restaurant food, since that is where most sodium comes from.
Swapping the shaker is one of several ways to lower blood pressure. Our guide on how to lower blood pressure without medication covers the others, including wall sits for blood pressure, beetroot and slow breathing.
The evidence is unusually solid for older, high-risk adults and thinner for everyone else. It is worth knowing which group you are in.
This article is for educational purposes and is not medical advice. Talk to a qualified clinician before changing your health regimen.
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