Nobody thinks that an excess of sodium is good for them, right? But just how much sodium is too much is hotly contested. And now to confuse things even further: A new mega-analysis of salt studies says while a low-sodium diet keeps blood pressure low, it’s actually linked to increased cholesterol levels and other heart disease risk factors. Uh … what? Should we be cutting back on salt or not?
Just last month, the Centers for Disease Control and Prevention released a report saying Americans in general consume way too much sodium, and it’s putting our health at risk. Numerous studies have shown excessive dietary salt can lead to hypertension (high blood-pressure), which is a major risk factor for stroke and heart disease.
But this new study—published online this week in the American Journal of Hypertension—reviewed data from 167 studies comparing high and low sodium diets, and the results are surprising. In folks with normal or high-blood pressure, a low-sodium diet did bring blood pressure down. But a low-sodium diet also corresponded to significantly higher:
- Cholesterol levels
- Triglyceride levels (a factor linked to heart attack and stroke)
- The enzyme renin (which is linked to high blood pressure)
- The hormones noradrenaline and adrenaline (which can affect blood pressure and heart rate)
“In my opinion, people should generally not worry about their salt intake,” said study author Dr. Niels Graudal, of Copenhagen University Hospital in Denmark.
Evidence about sodium conflicting as it does, I don’t plan to stock up on frozen dinners and canned soup (both notoriously high in sodium content) just yet. Maybe those on low-sodium diets tend to make up for the lack of salt by increasing their intake of other unhealthy substances. Or maybe sodium is something we shouldn’t be getting too much or too little of.
U.S. dietary guidelines recommend healthy, non-African American adults under 51 limit sodium intake to 2,3000 milligrams per day. Older adults, blacks and those with high blood pressure or diabetes should consume less than 1,500 milligrams daily. The American Heart Association says 1,500-mg should be the daily limit for everyone.
But maybe one-size-fits-all sodium guidelines are what lead to confusion. Cardiologist Suzanne Steinbaum told USA Today that “there are those who are more salt-sensitive than others.” In general, though, less salt is probably better, she said.
Graham MacGregor, a professor of cardiovascular medicine and chairman of the World Action on Salt campaign group, told Reuters he strongly disagrees with Graudal’s conclusions. The review “clearly shows once again that decreasing salt intake lowers blood pressure,” said MacGregor.
“This study, contrary to the authors’ claims, supports the wealth of evidence that reducing our salt intake will be immensely beneficial in preventing strokes, heart attacks and heart failure.”
If you are looking to cut your sodium intake, start by paying attention to nutrition labels and eschewing fast food. The majority of salt in American diets isn’t added during cooking or at the dinner table, the CDC says, but comes from the extremely high levels of sodium in packaged and restaurant foods.