Does potassium chloride provide a win-win by reducing sodium intake and increasing potassium intake?
Among all the horrors of our diets, a major risk is excessive dietary sodium intake, or high salt intake. It is estimated that millions of people die each year, primarily due to its negative effects on blood pressure and increased risk of stroke, heart attack, and kidney damage. Hypertension is still referred to as the “silent, invisible killer” because it causes few symptoms, yet it is one of the strongest independent predictors of some of the leading causes of death.
We have evolved to eat a diet that is very rich in potassium and low in sodium, but now that pattern has completely reversed. This reversal reflects a shift away from traditional plant-based diets that are high in potassium and low in sodium – fruits, vegetables, root vegetables, and tubers – and toward salty, processed foods that remove potassium, which is considered a “nutrient of public health concern” because 98% of the U.S. population does not even meet the recommended daily minimum intake. As mentioned previously, low potassium intake itself is associated with high blood pressure and cardiovascular disease. But few doctors actually consider telling their patients to eat more potassium-rich foods, such as fruits and vegetables, to better control blood pressure, even though several meta-analyses have confirmed that higher potassium intake reduces stroke risk.
The risk of stroke was also reduced, independent of the effect on blood pressure, consistent with other protective effects of potassium, such as reduced blood clot formation, reduced arteriosclerosis, and reduced free radical production. High sodium intake increases the risk of early death by 20%, and high potassium intake reduces the risk of early death by 20%. Sodium is found in junk, processed foods, while potassium is concentrated in healthy foods like beans and vegetables, so lower sodium intake and higher potassium intake can only be indicators of a healthier diet, meaning more plant foods and less junk food. How do we know that sodium is causally bad? Randomized controlled trials have shown that reducing sodium leads to lower blood pressure, so randomized controlled trials have shown that extra potassium intake may also lower blood pressure. So what about using potassium chloride instead of sodium chloride to add salt to your food? That’s what these zero-sodium salt substitutes contain, and you can see them below and at 2:28 of my video “Are Potassium Chloride Salt Substitutes Effective?”
Potassium chloride is considered a naturally occurring mineral salt, obtained in the same way as regular sodium salts. With too much sodium and not enough potassium, potassium chloride seems to be a win-win solution.
Eating whole, healthy plant foods is the best way to increase your potassium intake, especially since fruits and vegetables contain all sorts of other good stuff. But now there are 10 studies, consisting of 11 randomized controlled trials, showing that simply replacing potassium chloride with regular salt significantly lowers blood pressure in people with high blood pressure, suggesting that salt substitutes may also help prevent high blood pressure. We know that salt substitutes can lower blood pressure, but do they actually reduce the incidence of high blood pressure and, more importantly, disease endpoints like stroke and death? We won’t know until we test it.
A randomized controlled trial replaced household salt with just one-fourth as much potassium chloride. At that level, most people either couldn’t tell the difference or even preferred salt mixed with potassium. But did it actually have any effect? Even if you use a quarter of a salt substitute, your risk of developing high blood pressure is cut in half.
But what about actually following people to see if their risk of dying from cardiovascular disease changed? Over a period of about two and a half years, five kitchens at a veteran’s nursing home were randomly divided into two groups and salted their meals with either regular salt or a 50/50 blend of potassium chloride unknown to cooks and guests. People in the half-potassium group had about a 40% reduced risk of dying from cardiovascular disease and lived nearly a year longer. The difference in life expectancy at age 70 is “equal to the difference that would occur naturally in 14 (years),” meaning that switching to just half the amount of potassium salts appears to effectively make you more than 10 years younger in terms of mortality risk. In a recent large-scale randomized controlled trial in China that spanned five years and included 600 villages and more than 20,000 people, participants consumed either a salt substitute made with one-quarter potassium chloride or regular salt. Salt substitutes not only reduced stroke and cardiovascular events overall, they also reduced the risk of death from all causes.
China is the perfect environment for this research. That’s because up to 75% of the nation’s sodium intake comes from salt added in home kitchens and dining rooms, while most of the sodium in Americans’ diets comes prepackaged in the meat and processed foods we buy. However, it is certainly possible that food companies will make the switch themselves. Why didn’t you do that? And if these salt substitutes work well and taste just as good, why aren’t more people embracing them? The title of the Mayo Clinic review says it may “receive the benefits of a high-potassium Paleolithic diet without the toxicity.” So, “Are salt substitutes ready for prime time?” the commentator asks. What about safety? There are compelling arguments for the benefits, but what about the risks, such as “potentially deadly salt substitutes in the food supply”? Wait, what? Now let’s discuss the potential downsides.
doctor’s note
This is the second in a three-part series on salt and potassium. If you missed the first video, check out the mineral intake recommendations that only 1 in 6,000 U.S. adults meet. The series concludes with “Are potassium chloride salt substitutes safe and effective?”
“Evidence That Salt Raises Blood Pressure” talks about randomized controlled trials on sodium.
