The simple combination of sodium and chloride (NaCl) gives rise to a mineral, salt, with endless uses, particularly within the culinary world. Salt is known to enhance our taste perception — there’s a reason every good chef always has some on hand. For centuries, humans have been using salt to preserve and season food, however, the use of salt has skyrocketed in the modern world.
The recommends a daily intake of no more than 2000mg of sodium per day; however, they estimate that the average adult consumes 4310mg of sodium per day. This is more than double the recommended amount! The current overuse of salt poses a serious health problem as excessive salt intake has been linked to high blood pressure; high blood pressure is the main risk factor for cardiovascular disease and stroke. In Canada, cardiovascular disease is the second leading cause of death and accounts for .
There is no doubt that both the food industry and consumers have to work towards lowering daily sodium intake as processed foods account for 77% of sodium intake. This means that industries should aim to reduce salt content in their products and consumers should aim to make more conscious choices. But how do we reduce our use of something that tastes so good?
One proposed method for reducing sodium intake is to replace sodium chloride salt, which is typical table salt, with salt substitutes composed of either potassium chloride alone or in combination with sodium chloride.
Potassium, like sodium, is a critical electrolyte in our bodies. It is the ion with the highest concentration inside our cells. As such, it plays a critical role in maintaining cell function, nerve transmission, muscle contraction, and kidney function. Furthermore, potassium functions in conjunction with sodium to maintain normal cell fluids and blood volume. Too much sodium and not enough potassium can lead to fluid retention and subsequent increase in blood pressure; chronic increase in blood pressure can lead to the development of hypertension which places an excess load on the cardiovascular system and can predispose individuals to cardiovascular disease. Our bodies have adapted to retain sodium and excrete excess potassium, therefore, our bodies are not adapted to mitigate the current high sodium-low potassium diets of many individuals.
It’s not just excess sodium that poses a risk to our health, but too much or too little potassium can also lead to health consequences. Low potassium, known as hypokalemia, often results from reduced intake or excessive loss of potassium in the urine; the latter situation is more common as the kidneys can often compensate for reduced intake in normal individuals. However, in individuals who are malnourished or taking antidiuretics, reduced intake of potassium can become significant. Symptoms of hypokalemia include constipation, heart palpitations, fatigue, muscle damage, muscle spasms – hence the banana- and tingling. On the other hand, too much potassium, known as hyperkalemia, also poses serious health risks. It can be caused by increased intake or decreased renal excretion. High intake of potassium is unlikely to increase potassium levels sufficiently in most healthy individuals, however, in those with renal dysfunction, high potassium intake is much more likely to result in hyperkalemia. Mild hyperkalemia is typically asymptomatic, but extreme increases in potassium intake can cause cardiac arrhythmias, muscle weakness, or paralysis.
Overall, it seems that in healthy individuals with normal kidney function, it is hard to upset the balance of potassium significantly with an altered intake. This has led to the development of potassium chloride salt as an alternative to sodium chloride salt in an attempt to reduce sodium consumption and cardiovascular mortality while minimizing the impact on food taste.
A recent found that salt substitution may be effective in reducing cardiovascular mortality; it may even be more effective than salt reduction as potassium in the salt substitute is thought to have added benefits and mitigate the risks of high sodium. However, the authors importantly note that these studies were conducted on individuals with a higher-than-average risk for cardiovascular disease and/or an Asian diet that is typically high in sodium. Therefore, more research is still required to determine the efficacy and safety of salt substitution on a more global scale due to large variations in diets. Special caution is required for individuals with renal dysfunction and potassium sensitivity.
Potassium salt substitution is an attractive option for reducing sodium intake more seamlessly. However, some individuals note that potassium salt is significantly more costly than regular salt and too much potassium salt can leave food with an unpleasant bitter aftertaste. This being said, potassium salt seems to have a high potential for reducing global sodium intake. With more research, we may soon be asking for potassium chloride at the dinner table instead.
Daniela is a recent B.Sc. graduate from the program of Physiology at ¿´Æ¬ÊÓƵ.ÌýShe is very passionate about understanding the human body and how we can all individually adapt our daily lifestyles to improve its functioning.
Part of the OSS mandate is to foster science communication and critical thinking in our students and the public. We hope you enjoy these pieces from ourÌýStudent ContributorsÌýand welcome any feedback you may have!
