People who lower the amount of salt in their diets by using a salt substitute may significantly decrease the risk of developing high blood pressure, a study published Monday suggests.
The report, in the Journal of the American College of Cardiology, analyzed data from hundreds of men and women, ages 55 and older, who were in elder care facilities in China.
The data came from an earlier, larger study, called DECIDE-Salt, which included 1,612 participants. For the new analysis, researchers focused on 157 women and 454 men who had healthy blood pressure levels and were given food either with the usual amount of salt or with a salt substitute.
The researchers found that cutting salt back by more than a third by swapping in another mineral supplement — salty-tasting potassium chloride, along with other flavorings such as mushroom, seaweed and lemon — was protective against high blood pressure over a two-year period.
Dr. Yangfeng Wu, senior author of the study and executive director of the Peking University Clinical Research Institute in Beijing, said that although the study was conducted in China, the findings should apply to people in other countries, including the U.S. Anyone can benefit from replacing salt with a substitute, whether they have high blood pressure or not, Wu said.
Uncontrolled high blood pressure can raise the risk for numerous chronic diseases, including heart and kidney disease, diabetes and dementia.
Most Americans consume too much salt, about 3,500 milligrams a day, according to the American Heart Association. Currently, the Food and Drug Administration recommends that healthy adults consume no more than 2,300 mg (about half a teaspoon) of salt per day.
Potassium chloride, which combines the essential supplement potassium with chloride, tastes and acts like table salt without adding harmful sodium to the diet. The recommended daily allowance of potassium for people 19 and older is 3,400 mg (about two-thirds of a teaspoon) for men and 2,600 mg (about half a teaspoon) for women.
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Earlier studies showed that salt substitutes could lower blood pressure — systolic, in particular — among people with hypertension, Wu said. “The present study extended the effect of salt substitutes to people with normal blood pressure,” Wu said.
Systolic — the top number in a blood pressure reading — indicates the amount of pressure in the arteries, when the heart contracts and pumps blood through the body. Diastolic — the bottom number — is the pressure in the arteries between heart beats.
“High blood pressure is a leading contributor to deaths worldwide,” said Dr. Deepak Gupta, an associate professor of medicine in the division of cardiovascular medicine at the Vanderbilt Medical Center. “Diet is clearly a contributor,” he said.
Gupta, who was not involved in the study, said the salt substitute helped by lowering the amount of table salt, sodium chloride, consumed daily and adding in potassium.
“Americans in general have low potassium in their diets,” Gupta said. “Having a diet enriched in potassium, even if nothing is done on the sodium side, is likely to have an impact on lowering blood pressure.”
The new study used a particular type of substitute, but in the U.S., salt substitutes can be purchased that either completely or partially replace the salt.
It can be challenging for people to lower their salt intake long term unless they find a satisfying substitute, said Dr. George Dangas, a professor of medicine at the Icahn School of Medicine and chief of cardiology at Mount Sinai Queens, who was not involved in the new research.
“We live in a very salt-rich environment,” Dangas said. “We need to figure out how to make supplements that preserve the taste so they will enhance compliance with salt reduction.”
Before increasing potassium intake, people should talk to their doctors, Dangas warned. Some conditions, such as kidney disease, can lead to high potassium levels, and adding more of the mineral might be dangerous.
The overall message of the study is that “limiting salt in the diet can bring down blood pressure, which is all important to heart health,” said Dr. Michelle Bloom, system director of the cardio-oncology program at NYU Langone Health and a professor at the NYU Grossman Long Island School of Medicine.
“People need to be more cognizant of labels and to be really aware of what they are putting in their bodies,” said Bloom, who was not involved with the study.
Even lowering blood pressure by a couple of points “can lead to a substantial decrease in the likelihood of heart attack, heart failure and stroke” Bloom said. “The typical American diet contains a lot of processed packaged food that has a lot of salt in it that people are often not aware of. There are other ways to satiate that part of a person’s appetite without salt, such as spices and lemon juice.”
