Shahar Madjar, MD

How much more is there to say about salt? A month ago, I wrote here about the ways our bodies process salt, a compound that contains sodium and chloride. And in the article that followed, I told you about the proven benefits of the DASH diet (DASH stands for Dietary Approaches to Stop Hypertension) that calls for, among other recommendations, limiting the consumption of sodium. And yet, more evidence about salt consumption and its effect on health has recently been published, and the information is both convincing and important.

Dr. Yuan Ma from the Department of Epidemiology at Harvard School of Public Health and her colleagues analyzed data from six different prospective studies in healthy adults. The researchers examined the effect of the consumption of salt (sodium chloride) and that of potassium on cardiovascular events such as heart attacks and strokes). They looked at 10,709 study participants over a period of 8.8 years. The research was published in the New England Journal of Medicine in January 2022.

The researchers could have asked the participants in the studies to fill a diet diary in which they had recorded the types and quantities of food items they consumed. They would then have to estimate the amount of sodium in each item, and calculate the total amount of salt each participant consumed. But how much salt was there in a medium-size portion of French fries you had just bought at the fast-food joint down the street? It would depend on the amount of French fries, the amount of salt added at the store, and whether you shook the salt-shaker to add even more punch. Using this method, determining the exact amount of sodium consumed would be an elusive, futile endeavor.

Instead, the researchers measured the amount of sodium excreted in the participants’ urine. The body maintains a very constant level of sodium. The more sodium a person consumes, the more sodium would end up in that individual’s urine. And so, measuring the amount of sodium in the urine is a more accurate representation of the consumption of sodium.

Because the level of sodium consumption and excretion changes from one hour of the day to another, and from day to day, the researchers measured the amount of sodium excreted by each participant in several 24-hour urine samples.

In a similar manner, the researchers also examined the levels of potassium in the urine. Scientists were already aware of an interesting interconnection between sodium and potassium and the effect both have on hypertension. To put it in simple terms, consumption of potassium can counteract the harmful effect of excessive sodium consumption. And while healthy individuals can usually cope with high amounts of sodium, some patients with hypertension benefit from a diet limited in sodium and rich in potassium.

The results of Dr. Yoan Ma’s study were dramatic! Individuals with higher excretion of sodium and lower excretion of potassium (indicating higher consumption of salt and lower consumption of potassium) had higher risk of cardiovascular events. In other words, higher consumption of salt and lower consumption of potassium led to higher rates of heart attacks and strokes.

How much of a difference was there? Participants in the upper quartile of sodium consumption, for example, were 1.6 times (60%) more likely to develop cardiovascular event then those in the lowest quartile of participants.

How much sodium should you consume? According to the FDA, “Americans eat on average about 3,400 mg of sodium per day. However, the Dietary Guidelines for Americans recommends adults limit sodium intake to less than 2,300 mg per day.” And that is the approximate amount of salt in 1 teaspoon of table salt.

And how much potassium? The daily recommended amount is 2,600 mg for adult women, and 3,400 mg for adult men. Fruits and vegetables are excellent sources of potassium. A baked potato in its skin contains 900 mg of potassium; a cup of chopped tomato has 400 mg, a banana 422 mg. Plain yogurt and seafood are also excellent sources of potassium.

Any more advice? Shop for food items with lower sodium content (read the nutritional labels); Prepare your food with only a pinch of salt; Instead of salt, use spices such as paprika, cumin, and fresh herbs; When eating out, ask the server to go light on the salt and don’t use the salt shaker. Did I mention replace food that comes in packages with fruits and vegetables?

Any residual FOMO (Fear of Missing Out) on taste and flavor? Fear not! Your taste buds will adjust quickly.

Editor’s note: Dr. Shahar Madjar is a urologist at Aspirus and the author of “Is Life Too Long? Essays about Life, Death and Other Trivial Matters.” Contact him at smadjar@yahoo.com.