Does too much salt cause high blood pressure, or doesn't it? That debate has raged for decades, with a slew of studies finding "yes" and a slew of others finding "no." Two new studies out today in the journal Hypertension tip the scales in favor of reducing sodium—particularly for those 1 in 4 Americans who have high blood pressure. One study found that reducing salt intake from 9,700 milligrams a day to 6,500 milligrams decreased blood pressure significantly in blacks, Asians, and whites who had untreated mild hypertension. Another study found that switching to a lower-salt diet helped lower blood pressure in folks with treatment-resistant hypertension.
In the second study, those with an average blood pressure of 145/84 millimeters of mercury (mm Hg)—still above the healthy level of 120/80 mm Hg even though they were taking three or more medications—experienced an average blood pressure drop of 22.7 mm Hg (for the top systolic number) and 9.1 mm Hg (for the bottom diastolic number) when they switched from a high-salt diet, containing 5,700 milligrams of sodium a day, to a low-salt one containing 1,150 mg.
Lowering sodium intake, though, involves a lot more than setting aside the salt shaker. An April study from Emory University found that only one third of heart-failure patients succeeded in reducing their sodium intake to the recommended 2,000 mg a day even when they made an effort to follow a low-sodium diet. (Reduced sodium is recommended to prevent a dangerous retention of fluid common with this heart condition.) Bottom line: Unless you read every food label and never dine out, you're probably getting far more than the 2,400 mg sodium limit recommended for healthy adults. If you're unexpectedly getting too much sodium, here are some likely culprits:
- Miso Soup: 1 cup of miso soup typically contains 700 to 900 milligrams of sodium. Look for canned soups with "low sodium" or "reduced sodium" on the label.
- Cottage cheese: Some low-fat brands pack more than 900 mg of sodium into a 1 cup serving. Better choice: One cup of plain yogurt, which has about 150 mg, or 1 ounce of Swiss cheese, which contains 54 mg.
- Salsa: Many brands, like Pace Chunky Salsa, contain 230 mg of sodium per 2-tablespoon serving. Look for brands made with "salt-free" tomatoes.
- Dill pickles: A single dill typically contains 830 mg of sodium. Have a sweet gherkin instead or, better yet, ultralow-sodium fresh sliced cucumber.
- Croissant: All that buttery flakiness packs in more than 400 mg of sodium. Ditto for corn bread. Instead, choose reduced-sodium whole-grain breads or, heck, even white bread; either typically has fewer than 150 mg per slice.
- Alaska king crab: A mere 3 ounces contains more than 900 mg of sodium. Better fish choices: Fresh baked salmon, swordfish, and flounder all contain fewer than 150 mg per serving.
- Kellogg's Raisin Bran: It sounds so nutritious, but the cereal packs 362 mg of sodium per 1-cup serving. Choose Kellogg's All-Bran cereal (73 mg of sodium) or Frosted Mini-Wheats (5 mg) instead. (Bonus: The alternatives also contain less sugar.)
- McDonald's Egg McMuffin: The palm-size sandwich contains 820 mg of sodium. Better McDonald's breakfast choices: A plain toasted English Muffin (280 mg of sodium) or two scrambled eggs (180 mg).
- Salad dressings: Some brands—like Newman's Own Low-Fat Balsamic Vinaigrette—pack in upwards of 700 mg of sodium per 1.5 ounce serving. Drizzle on your own oil and vinegar or read labels carefully and aim for fewer than 150 mg per serving.
- Canned tuna typically contains 300 mg of sodium per 3-ounce serving. Mix in a tablespoon of mayonnaise and you get another 90 mg. Better choice: fresh grilled tuna steak, which has just 40 mg of sodium.