High potassium foods have been shown to reduce cardiovascular disease, blood pressure, and strokes. The key to this reduction is an increase in the potassium sodium ratio of the diet. Much emphasis in the medical literature has been only on reducing sodium in food. After Finland succeeded in reducing strokes and cardiovascular deaths by using a potassium replacement for some of the sodium in salt, interest in potassium increased. Finland reduced the amount of hypertension and strokes by replacing sodium in processed foods and at the table. Since then there has been an increased interest in other countries, hoping to repeat Finland's success. However, one of the difficulties is a salt substitute taste change. Potassium salt adds a different taste to food than sodium salt.
Salt Substitute Taste Change Study
A study (1) published this year examined salt substitute taste change by replacing various amounts of sodium chloride with potassium chloride. There have been several studies showing that when potassium has been exchanged for sodium in salt, it has been possible to reduce blood pressure. However there have been limits to the amount of sodium that can be replaced. Participants in studies replacing sodium with potassium in salt complain of bitterness and a metallic taste. This makes compliance very difficult.
This study tried to determine how much potassium could replace sodium without affecting taste. The researchers replaced the sodium in salt with potassium at a 25% level, 33% level and 50% level. They used rice to provide a bland base taste. It was cooked with these 3 levels of salt replacement. The researchers then had people report whether they could distinguish a difference in taste.
They found that very few could distinguish any difference in taste at the 25% replacement level. They found that more people were able to distinguish a taste change at the 33% level. Even more could tell a difference at the 50% level. There was no significant difference between those who distinguished at the 25% level from random chance. However the 33% and 50% showed a significant difference. The salt substitute taste change occurred above the 25% level.
The researchers also found gender and age made a difference in the ability to determine a taste difference. Men were more sensitive to the change in taste by potassium than women were. And those who were younger were more sensitive to the change in taste than those who were older.
How The Study Was Done
The research subjects tasted 3 different samples of rice, one after another. One sample of rice was cooked with the potassium chloride substituted salt and 2 samples had normal salt. The order of sampling was randomly rotated. After sampling all 3, the research subjects said which of the 3 samples had a different taste. However when asked about the change in taste only a few said that the salt substitute tasted more bitter or more metallic. Most simply said that they distinguished a taste difference.
The researchers discussed some of the limitations of their study. One limitation was that they only tested the effect of the salt substitution on rice. The salt substitute taste change may be less noticeable at higher percentages with other types of food. Also the subjects may have had taste fatigue since they were tasting 3 samples one after another. The researchers did have their subjects drink some water in between samples to try to reduce this effect to a minimum.
Problems With Potassium Salt Substitutes
There are potential problems with potassium salt substitutes used in a public health setting. When potassium as a salt is added to food it is more quickly absorbed than potassium found naturally in food. The potassium that is found naturally in food is attached biologically to organic molecules in the food, and is therefore more slowly released than when it is in a salt form. The quick absorption can lead to quicker changes in blood levels, and higher blood levels of potassium. For those with health problems, such as heart problems or kidney problems, this can lead to abnormalities of heart rhythm and kidney retention. People with these problems must have their diet regulated by a physician.
This type of salt substitution was done in Finland in the 1970s and resulted in a marked decrease in blood pressure, strokes, and cardiovascular disease in the nation. However this has leveled off in recent years, so that Finland has approximately the same level of these diseases as in the United States.
Because it is a relatively limited amount of potassium that can be substituted for sodium in salt, a larger dietary change is required to reduce these diseases even further. A further reduction in these diseases requires a change in diet. A simple change in salt composition has a limited effect. The real solution to hypertension, strokes and cardiovascular disease is a high potassium foods diet. When taste enhancement is desired, it can be obtained by the skillful use of spice combinations rather than a salt shaker.
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1. Applying the Triangle Taste Test to Assess Differences between Low Sodium Salts and Common Salt: Evidence from Peru. Saavedra-Garcia L, Bernabe-Ortiz A, Gilman RH, Diez-Canseco F, Cárdenas MK, Sacksteder KA, Miranda JJ. PLoS One. 2015 Jul 30;10(7):e0134700. doi: 10.1371/journal.pone.0134700. eCollection 2015.
