Scientists Just Found the Salt Limit That Pushes Your Heart to the Breaking Point
Too much salt in your diet can be a deadly thing. Now, scientists may have just pinpointed the level of sodium intake that could literally break your heart. Researchers at Vanderbilt University tracked the long-term health of residents in the southeastern United States who were at higher risk of heart issues. People who consumed roughly 4,200 milligrams of sodium a day—almost twice the recommended maximum—had a 15% higher risk of heart failure, they found. At the same time, cutting down on high salt intake even a little could have a big effect on people’s heart health. “Collectively, these results suggest even modest reduction in sodium consumption may significantly reduce the burden of [heart failure] in this high-risk population,” the authors wrote in their paper, published this month in JACC: Advances.
High salt, high risk Sodium is an essential nutrient, but it’s well known that too much of it a day can raise your risk of high blood pressure and other cardiovascular problems, including heart failure. Unfortunately, most Americans are eating considerably more sodium than the recommended amount of 2,300 milligrams a day. According to the study authors, however, there’s been relatively little research quantifying the level of sodium intake that can contribute to new cases of heart failure. So they decided to analyze data from the Southern Community Cohort Study (SCCS), a long-running project following people in the southeastern United States to better understand the root causes of cancer and other chronic diseases.
All told, they examined the health of 25,306 SCCS middle-aged participants without preexisting heart failure over a median length of nearly 10 years. The participants’ sodium consumption was measured through a questionnaire of their dietary habits taken at the start of the study. Over the study period, about 27% of participants developed heart failure.
The average daily sodium intake of the volunteers was 4,269 milligrams of sodium a day. And compared to the maximum recommended level, this amount of daily sodium was associated with a 15% higher risk of heart failure, the researchers found, while each extra 1,000 milligrams of sodium was associated with an 8% higher risk of heart failure, even independent of other known risk factors like physical activity, total calories, or high cholesterol levels. What to do about high sodium? On the positive side, the researchers calculated that even a subtle decrease of sodium consumption on a population level could meaningfully lower heart failure risk. Just dropping the average sodium intake down to 4,000 milligrams per day in a population could prevent 6.6% of new heart failure cases over a 10-year period, they found.
Lowering sodium intake nationwide is easier said than done, however. Most people’s daily sodium comes included in the foods we eat, rather than from any table salt we add ourselves. And the biggest contributors to sodium intake (over 70%) are from the most convenient and tasty foods we can have, namely prepared or prepackaged meals. Avoiding these foods can be even more of a challenge in the poorest neighborhoods where many of the SCCS participants and plenty of other Americans reside, the researchers further note. They argue that it will take “multilevel public health strategies to achieve lower dietary sodium intake in high-risk resource-limited communities.”
