What are salt substitutes and are they harmful to those with kidney disease?

Sodium is frequently present in large concentrations in processed meals including breads, meat products, and snack foods, as well as in sauces (such as those derived from soy or fish). Picture: Pexels

Sodium is frequently present in large concentrations in processed meals including breads, meat products, and snack foods, as well as in sauces (such as those derived from soy or fish). Picture: Pexels

Published Sep 11, 2023

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Dietary trends are shifting as a result of lifestyle changes, growing urbanisation and the manufacture of more and more processed food. Foods that have been heavily processed are becoming more widely available and more inexpensive.

Globally, people are eating more calorie-dense meals that are heavy in salt, sugar, saturated fats and trans fats. The main source of sodium is salt, and consuming more sodium is linked to hypertension as well as a higher risk of heart disease and stroke.

A healthy diet should include fruit, vegetables and dietary fibre, which may be found in whole grains. However, as people’s eating habits change, they are consuming less of the essential foods.

Potassium, which is found in fruits and vegetables, helps lower blood pressure.

Processed foods can contribute salt to the diet in two ways: either they are particularly high in salt (like ready made-meals, processed proteins like bacon, ham and salami, cheese, salty snack foods and instant noodles, among others), or they are frequently consumed in large quantities (like bread and processed cereal products).

Additionally, salt is added to food at the table (soy sauce, fish sauce and table salt) or during cooking (bouillon and stock cubes).

Consumers should check food labels and select low-sodium items since some manufacturers are reformulating recipes to lower the salt content of their goods.

In August, the Food and Drug Administration (FDA) issued a proposed rule that would permit food makers to substitute salt substitutes for the genuine thing. The public health initiative aims to lower the amount of extra sodium added to meals.

The World Health Organization reports that most individuals consume too much salt – on average, 9 to 12g a day, or roughly twice the maximum amount that is advised.

Adults who consume fewer than 5g of salt a day have lower blood pressure and a lower risk of heart attack, stroke and other cardiovascular diseases.

All salt that is taken should be iodised or "fortified" with iodine, which is necessary for foetus and young child brain development and for enhancing general human mental performance. Picture: Pexels.

Cutting down on salt has several advantages, the main one being a decrease in high blood pressure. WHO member states have committed to a relative 30% decrease in world salt use by 2025.

One of the most economical steps a nation can take to improve population health outcomes has been identified as reducing salt intake.

A year of extra healthy life can be obtained for a cost that is less than the average yearly income or gross domestic product per person, by implementing key salt reduction methods.

If worldwide salt consumption were to be brought down to the recommended amount, it is predicted that 2.5 million fatalities may be avoided annually.

Potassium chloride, sometimes referred to as potassium salt, is one of the suggested replacements. The natural salt substitute offers a comparable flavour without the drawbacks of sodium.

However, others who advocate for those with renal illness caution that adding potassium to meals could be harmful to those who have the disease, even killing them.

Immediately following the FDA’s announcement on August 8, the American Association of Kidney Patients (AAKP), the Academy of Nutrition and Dietetics (the Academy), and the National Kidney Foundation released a joint statement outlining their objections to the proposed rule.

Although they praised the FDA’s efforts to lower the sodium content in packaged goods, the groups said: “We must balance population health goals and the acute needs of an already medically complex population.”

An estimated 843.6 million people are thought to be affected by CKD stages 1 through 5 globally, according to the National Institutes of Health, based on the findings of research looking at the global prevalence of Chronic Kidney Disease (CKD).

Many individuals with chronic renal disease, especially those with kidney failure, cannot usually eliminate potassium. Potassium can build up in the blood of these persons if they consume large amounts of the mineral.

Hyperkalemia, or high blood potassium levels, can result in irregular heart rhythms and potentially abrupt cardiac death.

“Given the very high estimates of those who are unaware they have compromised kidney function and the clinical consequences of hyperkalemia, adding ‘hidden potassium’ in the form of potassium chloride substitutes to the American diet is a risk that should not be taken,” the AAKP joint statement said.

The proposed modifications, according to several organisations fighting for CKD patients across the world, are most likely to have a little impact on those receiving treatment for severe renal disease.

Increased potassium in foods may have an adverse effect on people with impaired kidney function who are also taking angiotensin-converting enzyme inhibitors, angiotensin 2 receptor blockers, or another medication called spironolactone.

However, there are medications that can prevent this, according to research from the National Kidney Foundation of South Africa.

The auxiliary medications function by attaching to intestinal potassium, which lowers blood potassium levels, writes Everyday Health.

People with chronic renal disease who are taking medications that can make having too much potassium a problem are frequently administered the drugs. Regardless of the FDA move, the individuals would also have their potassium levels monitored regularly.

People are aware that sodium is bad for them and that they should restrict their salt intake, especially if they have health issues like high blood pressure, chronic renal disease or bone disease.

According to the National Kidney Foundation, eating too much salt can contribute to renal disease. Additionally, it contributes to heart disease, the leading cause of death worldwide, high blood pressure and stroke.

In 600 communities in rural China, a randomised clinical trial comparing the effects of salt and a potassium-based salt substitute was conducted, as reported by Healthline.

Nearly 21 000 participants who were 60 years of age or older and almost all of them had a history of stroke, hypertension, or both, were included in the study. 75% sodium chloride (table salt) and 25% potassium chloride made up the salt substitute used by 50% of the participants.

Regular salt was used by the other half.

Following up after around five years, the researchers discovered that those in the salt substitute group had decreased incidence of stroke, major cardiovascular events and all-cause mortality.

The study’s main limitation was that it didn’t include patients with kidney illness or who were taking medications that made them more likely to develop hyperkalemia. As a result, the study can’t tell us how the extra potassium might affect this population.

The kidney organisations welcome the regulation but acknowledge that it might have unintended consequences.

They also emphasise the need for close monitoring of those with chronic kidney disease who are taking drugs that increase their risk of hyperkalemia.