Eating too much salt is making Americans sick. Even a 12% reduction can save lives

Even amid the coronavirus pandemic, heart disease continues to be the nation's leading cause of death. And much of it is preventable through a healthier diet.

The Food and Drug Administration released new sodium targets Wednesday aimed at nudging food companies to cut the amount of salt in processed and prepared foods. The cuts are intended to reduce Americans' sodium intake by about 12% over the next 2 1/2 years.

It's an incremental step, as the agency hopes to see even deeper cuts in years to come, but reducing sodium consumption even this much could have big public health benefits, says the FDA's acting commissioner, Dr. Janet Woodcock.

"Too much sodium is making people sick. It's leading to hypertension, and that causes both heart disease, strokes and even kidney damage, and it's preventable," Woodcock told NPR in an interview.

She says the agency is focused on pushing the food industry to change, since it's unrealistic to expect massive behavior change in the population and people don't have control over the sodium levels in packaged foods. She notes that even toddlers and kids consume too much sodium in the United States. "People can't do this on their own because it's in the foods they buy," she says.

Every day, about 1,800 people die from heart disease in the United States. And, unlike a virus that can kill quickly, deaths from heart disease are linked to decades of unhealthy eating habits.

Currently Americans consume 3,400 mg of sodium per day on average, vastly exceeding the U.S. government's latest dietary recommendation of a maximum of 2,300 mg of sodium per day, or about a teaspoon of salt.

If Americans reduced their intake to the recommended level, it could prevent an estimated 450,000 cases of cardiovascular disease and save roughly $40 billion in health care costs over 20 years, according to a statement by the American Heart Association.

The proposed 12% reduction is an important step in the right direction, says Dariush Mozaffarian, a cardiologist and the dean of the Friedman School of Nutrition Science and Policy at Tufts University. But he'd like to see more action to reduce consumption down to the recommended 2,300 mg per day. "The FDA really has to act, and very soon, for the longer-term goals to reduce sodium down to where it's safe for the American public," he says.

More than 70% of the sodium that Americans consume comes from packaged and prepared foods, rather than from the saltshakers in their homes, and there are some surprising contributors. Take a sandwich: Each slice of bread can contain 200 mg, or more, depending on what brand you buy. Add in some deli turkey, and it's easy to add another 650 mg. (See a breakdown of a typical turkey sandwich here.)

Sodium content in packaged foods varies a great deal by brand, with a slice of frozen cheese pizza, for example, ranging between 370 mg and 730 mg of sodium. Even the foods we would use to make a pizza at home, such as canned tomato sauce and pepperoni, can have high sodium levels, which consumers may not be aware of, Woodcock notes.

Woodcock said in her statement Wednesday that some food companies have already been reducing sodium in their foods, since a draft version of this week's targets was released in 2016.

The sodium reduction targets are voluntary, but Woodcock says other countries have had success with a similar approach. For instance, a U.K. salt reduction initiative led to a 15% reduction in the average salt intake of the population, and Woodcock says that the United Kingdom has seen a reduction in average blood pressure and that the sodium reduction is also linked to lower rates of strokes and heart attacks.

"We can't claim that all of that is totally caused by the reduction in sodium in the diet, but we're sure that that was a contributor," Woodcock says.

And most recently, a study published in The New England Journal of Medicine from China points to similar benefits. When groups of people in Chinese villages substituted potassium chloride for table salt, "they saw significant reductions in heart attacks and strokes," says Dr. Donald M. Lloyd-Jones, president of the American Heart Association.

Overall, it's clear that cutting salt intake benefits health, says Lloyd-Jones. "This is solid science. If we can remove sodium from the processed foods in our food supply, consumers won't even notice, but they'll reap the health benefits," he told NPR in an interview.

The ways in which too much sodium can harm the body are well understood. Too much sodium leads the body to retain water, which is pulled into the blood vessels. This can increase the volume of blood. "It's like turning up the water supply to a garden hose — the pressure in the hose increases as more water is blasted through it," according to the American Heart Association's explainer.

And, over time, this leads to disease. "The kidneys get stressed, the blood vessels get stressed, the heart gets stressed," says Mozaffarian.

Sodium plays a key role as a preservative and taste enhancer in packaged food, according to the American Frozen Food Institute. And "sodium reduction is complex," the industry group says, but food companies are already working to reduce sodium "by offering a variety of products to meet consumer demands – lower sodium, reduced sodium, lightly salted, and no salt options," according to a news release from the group, and plan to continue to work with the FDA on its sodium reduction targets. [Copyright 2021 NPR]