(CBS) - A new study from the New England Journal of Medicine says more 1.5 million heart-related deaths worldwide can be blamed on eating too much salt.
Dr. Tara Narula, a cardiologist at Lenox Hill Hospital in New York City, says thousands of American lives could be saved every year if people cut their sodium intake by half.
"Americans eat almost three to four times the recommended daily amount of salt. Salt is an essential nutrient, but what happens when you get too much salt is it raises your blood volume, and that increased blood volume causes increased blood pressure. And that's really the link."
Narula says a heightened blood pressure leads to artery disease, heart failure or heart attacks, strokes and kidney damage. That's the case for the nearly 58,000 Americans who died from heart-related issues last year, according to the study.
The American Heart Association says 90 percent of Americans consume too much salt, and 1 in 3 have high blood pressure. The recommended daily sodium intake, according to the FDA, is 2300 mg, while the AHA recommends 1500 mg.
"Anywhere in that range is usually acceptable, but as a cardiologist I usually tell patients [1500 mg]," Narula said.
On the other hand, recent studies claim too little salt can be dangerous as well, but Narula says these findings should be, so to speak, taken with a grain of salt.
"There [aren't] proven dangers yet of too little salt, although there is some controversy now about how low to go," Narula said. "These two studies that came out in the New England Journal this week question if lower than 3 grams a day might be associated with increased risk, but there are some limitations to this study. It wasn't a cause [and] effect study, it only followed people for around 3.7 years and there are some concerns with how the study was conducted, how salt was measured."
Narula says that this worldwide problem stems mainly from prepackaged food.
"A lot of people come to my office and say 'I don't add salt to my food, I don't cook with salt.' And that's not really where the problem is," Narula said. "Eighty percent of the salt we eat comes from packaged food or comes from restaurants, and it's very sneaky salt. And people don't realize that."
Only 10 percent of our daily salt intake is added at the table, while 65 percent comes from groceries and 25 percent from restaurants. Narula says calling attention to the problem will prompt more large-scale change.
"It falls in some ways as a public health issue," Narula said. "The way that we put calorie counts on our menus, we need to start doing this with sodium counts. Philadelphia is doing this, California is doing this. We tell people, 'Have the knowledge, count your counts,' but if we make it easy for them, it's much better."