I heard about a study that questioned the link between sodium and high blood pressure. I'm skeptical. What's the story?
Skepticism was a common reaction to that study, for good reason.
The study was conducted in Europe and published in the Journal of the American Medical Association. The researchers tested urine samples of nearly 3,700 participants to measure sodium levels, then followed up with them an average of 7.9 years later. They didn't find a link between sodium and high blood pressure, and furthermore, they found cardiovascular deaths were higher among those with lower sodium levels.
But almost immediately, other scientists questioned the study's methodology and conclusions. First, participants were relatively young (average age about 41) -- heart disease and hypertension often don't develop until people are older. They were all white -- other populations, especially African-Americans here in the U.S. -- are known to be more sensitive to the effects of salt. And, the connection between low sodium levels and higher cardiovascular risk was based on that single, baseline urine test -- which may have little or no bearing on actual sodium levels over years.
The findings were also at odds with the mountains of evidence from other research, including a recent study from the Centers for Disease Control and Prevention. That study found that Americans who eat a diet high in sodium and low in potassium have a 50 percent increased risk of death from any cause, and about twice the risk of death from heart attacks.
Americans average about 3,300 milligrams of sodium in their diet every day -- that's at least 1,000 milligrams too much for most people. Anyone 51 or older, African-Americans of any age, and anyone with high blood pressure, diabetes or chronic kidney disease should limit consumption to 1,500 milligrams.
However, most of the sodium we consume doesn't come from the salt shaker -- it's widespread in frozen dinners, canned goods, cheese and cured meats, among other foods.
So, what to do? The "10 Tips Nutrition Education Series" from MyPlate.gov offers some great advice, including:
- Fill up on fresh, home-prepared foods, especially fruits and vegetables, which are naturally low in sodium.
- Reduce salt use gradually. Your taste buds will change over time.
- Read nutrition labels -- pay more attention to the milligrams of sodium than the percent. The percent is based on a "Daily Value" of 2,400 milligrams of sodium, an amount higher than current recommendations.
See http://www.myplate.gov and click on the "10 tips" icon for more tips on salt and sodium.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or firstname.lastname@example.org.
Editor: This column was reviewed by Hugo Melgar-Quinonez, food security specialist for Ohio State University Extension and associate professor in human nutrition for the College of Education and Human Ecology.