Diet, Health

Trial Study Shows How Swapping Salt With Reduced-Sodium Salt Can Reduce Stroke Risk


In a rather large and randomized trial in rural China, researchers found that individuals that used reduced-sodium salt had lower risk of having a stroke or risk or death. Oftentimes, high sodium and low potassium levels in one’s diet is linked to high blood pressure, as well as an increased risk of heart disease and premature death.

Moreover, studies have found that reduced-sodium salt also doesn’t seem to increase the risk of hyperkalemia, a disease that is associated with incredibly high levels of potassium in one’s blood. The study hopes to show that by pushing the use of reduced-sodium salt could be one very economical and cost-effective way to help those in lower-income households and disadvantaged populations improve their health.

According to the Centers for Disease Control and Prevention (CDC), they report that 47% of the adults within the United States, which is equivalent to around 116 million people, are living with high blood pressure, otherwise known as hypertension.

This type of health condition adds to the risk of heart disease, kidney disease, and stroke. The CDC also shares that back in 2019, hypertension was considered the main cause, or an association, of the deaths in over half a million individuals residing in the United States.

Moreover, the World Health Organization (WHO) reports that over 1.28 billion adults have been diagnosed with hypertension all over the world. And alarmingly, at least two-thirds of this number are adults that are living in low to middle income countries.

There are quite a few things that attribute to high blood pressure that are preventable, such as alcohol consumption, smoking, being overweight and a lack of physical activity.

Another association of hypertension and added risk of cardiovascular disease and premature death are high levels of sodium and low levels of potassium in one’s diet, both items that can be prevented as well.

There is a lot of evidence that shows how reducing one’s intake of sodium, as well as taking potassium supplements, are both easy ways to help lower one’s blood pressure.

In order to prevent unhealthy heart conditions, people can actually replace their ordinary salt that they usually use with their food to the reduced-sodium salt. This helps because regular salt is made of sodium chloride, while the reduced-sodium type is a mixture of sodium chloride and potassium chloride, making it a better choice when it comes to heart health.

Moreover, this type of table salt is easily available and better yet, inexpensive. Plus the taste in quite similar to regular salt.

Yet, there is still lacking evidence that people that use this type of reduced-sodium salt to both preserve and season their food are also less likely to suffer a stroke or premature death.

Plus, some experts explain that they are concerned about how using reduced-sodium salt can still raise the potassium amount in one’s blood to extremely dangerously levels, which is the health issue known as hyperkalemia, as mentioned earlier.

A new and rather large trial has been going on in a rural portion of China that’s looking into the long-term health effects of reduced-sodium salt. The results have since shown that this type of salt not only lowers the risks of stroke and death, but it is also said to be very safe to use too.

The study concentrated on participants that had experienced having a stroke, as well as older folks with a known history of hypertension. The paper, which discusses the trials results, was published in The New England Journal of Medicine, goes under the name Salt Substitute and Stroke Study, or SSaSS.


How The Trial Study Worked

The scientists gathered 20,995 participants from 600 different villages found in rural China. The median age of the participants at the beginning of the study was 65.4 years, with half of them female.

From the total number of participants, around 72.6% of them had experienced a stroke, while 88.4% of them had a history of hypertension. The scientists assigned the groups at random, with half of the participants being made to continue using ordinary salt, which was considered the control group. The other half was made to use the reduced-sodium salt made from 25% potassium chloride and 75% sodium chloride by weight.

Then every 12 months, the researchers visited some of the villages to see whether the study participants were in fact, using the right type of salt. In order to confirm this, they even measured the amount of potassium and sodium found in their urine, as well as taking blood pressure readings.

These follow up periods lasted for around 4.74 years, and what they found was that in the villages where the participants were made to use the reduced-sodium salt, there was a 13% lower rate of strokes than in the villages where they participants were made to use regular salt.

The results pointed at how ‘the rate of strokes was 29.14 events per 1,000 person-years for the reduced-sodium salt group and 33.65 events for the ordinary salt group.’

Moreover, the study showed that the ‘mortality rate was 39.28 deaths per 1,000 person-year years for the reduced-sodium salt group and 44.61 events for the regular salt group,’ which basically equals to a reduced risk of at least 12%.

In addition, there was no substantial difference in the rates of the more serious adverse events that are normally associated with hyperkalemia in the group using reduced-sodium salt as compared to the control group.


Could It Become Used Throughout the Populations?

The study authors explain that the scale of protection was quite similar to another recent modeling study, where an estimated population-wide use of salt substitute in China could reportedly ‘prevent 365,000 strokes and 461,000 premature deaths’.

They also share that by using a salt substitution, it could be an economical, low-cost change for those in lower-income or disadvantaged populations that normally use big quantities of salt in their cooking and food prep to lessen health risks.  This research was also conducted in rural China where people tend to prepare their own food rather than buying processed food.

In an interview with Medical News Today, the lead study author, Prof. Bruce Neal from the George Institute for Global Health located in Newtown, Australia, was asked whether these results could also be applied to other world populations.

One example would be in the United States, where the CDC shares how many Americans get around 70% of their dietary sodium intake is from processed food, or food they eat in restaurants.

Prof. Neal explains, “[The] benefits of lowering sodium, increasing potassium, and reducing [blood pressure] are likely to be highly generalizable, wherever [they are] achieved in the world.”

But he also pointed out that most of the benefits of people using the reduced-sodium salt would be in areas where people have ‘the most control over the amount and type of salt in their food.’

He adds, “The trial results provides a strong, indirect case for reducing sodium and maximizing potassium in processed foods.”

He also pointed out that as a safety precaution, the study trial made sure to exclude any participants that were using a certain type of diuretic that works to lessen potassium excretion, those that take potassium supplements, or those with serious kidney disease.

Prof. Neal also denied that this point managed to undermine the findings of the study that showed how reduced-sodium salt is indeed, safe.

“We delivered the intervention safely and effectively by asking people to self-identify and exclude themselves if they were at risk of hyperkalemia. This was a simple and highly pragmatic approach that could be easily replicated anywhere to exclude people at risk,” he explains.


Highly Impressive Results

In another editorial, pediatrician and senior consultant in pediatric nephrology at the Massachusetts General Hospitallocated in Boston, Dr. Julie R. Ingelfinger, was excited about the study findings.

She explained, “The results of the SSaSS appear impressive. If the strategy is feasible over time, the salt-substitute approach might have a major public health consequence in China, and possibly elsewhere.”

But she also points out that there were some limitations to the study, focused mostly on the potential risk of hyperkalemia.

She shared, “For example, serial monitoring of potassium levels was not performed in the trial, and it is possible that hyperkalemia episodes were not detected. Furthermore, persons with a history of medical conditions that may be associated with hyperkalemia (e.g. chronic kidney disease) were not studied.”

Prof. Ingelfinger also explains that another limitation was that the scientists didn’t investigate the effect of the salt substitutes with either lower or higher levels of potassium chloride.

Like many other studies before this, there is still a need for further investigation into the topic but so far, these results are still considered quite promising.