Hold The Salt: How Warning Labels Can Help Fight The "Silent Killer"

​Aviva Musicus, Doctoral Student, Harvard T.H. Chan School of Public Health

​If you visit a New York City or Philadelphia restaurant (when you’re able to go out to eat again), you may be surprised to see a label on the menu that you’re unfamiliar with. Both of these cities require chain restaurants with 15 or more locations nationwide to post sodium warning labels next to menu items and combination meals containing more sodium than the recommended daily limit of 2,300 mg. A single menu item with over a day’s worth of sodium may sound like a rarity, but at Applebee’s, for instance, every single sandwich and pasta dish has more than 2,300 mg of sodium. Sodium warning labels are a relatively new policy tool that cities can use to help educate consumers about the sodium content of their foods, and prompt restaurants to reduce sodium content to avoid labels.

​Is sodium really that bad for us, though? Unfortunately, yes. High sodium intake contributes to high blood pressure, also known as the “silent killer”—its symptoms may not be obvious, but it’s one of the major risk factors for cardiovascular disease, the number one cause of death in the U.S. and worldwide. Almost all of us eat more salt than recommended by the 2015-2020 Dietary Guidelines for Americans, and nearly half of Americans have high blood pressure. Sodium warning labels could be a useful tool to reduce sodium consumption, because the majority of sodium in the American diet comes from restaurants and packaged foods, but consumers are largely unaware of the sodium content of restaurant foods, underestimating it by an average of 1,000 mg per meal.
 
So are sodium warning labels an effective tool for sodium reduction? Before Philadelphia passed their sodium warning label requirement into law, our research team collaborated with the Philadelphia Department of Public Health to answer that question. At the time, New York City was in the process of evaluating their policy (and they still are), so there was no data on how consumers would react to sodium warning labels or which label designs were likely to be most influential. Our study assessed the extent to which sodium warning labels using different words, icons, and colors influenced restaurant meal choices, restaurant meal perceptions, and sodium knowledge. Through a series of online randomized controlled trials, we found that “traffic light” and red “stop sign” warning labels significantly reduced the amount of sodium ordered compared with a no-label control, by 46–68 mg. Warning labels also increased consumers’ knowledge about high sodium content in restaurant meals. Designs with text explicitly using the word “warning” were most helpful. Philadelphia incorporated our findings into the city’s eventual sodium warning legislation, mandating a sodium warning symbol accompanied by “SODIUM WARNING” text. A real-world evaluation of the policy’s effect in restaurants has yet to be published, but our team is currently evaluating the effects of sodium warning labels in a hospital cafeteria setting.
 
If you don’t live in New York City or Philadelphia, there are still ways for you to reduce your sodium intake. Some packaged and restaurant foods can have surprisingly high levels of sodium even if they don’t taste salty, like bread, pizza, sandwiches, deli meat, and soups. When buying foods at the grocery store, you can check the nutrition facts label to compare sodium levels across products—you may be surprised by the variability! At restaurants, opt for items with less cheese and meat and more veggies, and ask for sauces on the side. And when in doubt, eating smaller portions is always an easy way to reduce your sodium intake.