Shaking Your Salt Habit

Hearing that you should reduce your salt intake to keep your blood pressure in check is like being reminded by your dentist to floss every day -- you know you should, you've been hearing it for years, but you rarely get around to it. Even though it's no secret that a high-salt diet can lead to elevated blood pressure, which puts you at risk for stroke, heart disease, and kidney failure, cutting back on sodium hasn't been a high priority -- thanks in part to the media's focus on artery-clogging cholesterol, risky trans fats, and the almighty calorie.

Salt isn't all bad, though. According to the Institute of Medicine of the National Academies, your body needs 1,500 milligrams of sodium (just over 1/2 teaspoon of salt) every day for basic functions like carrying nutrients to cells. Most Americans get more than double that amount: 4,000 mg per day on average, reports the Center for Science in the Public Interest (CSPI). The problem is that excess sodium makes your body retain water, which in turn can increase blood pressure and make your heart pump harder than it needs to. The pressure of blood hitting the artery walls can harden them and make them less able to dilate, upping your risk for heart disease and stroke.

Some of us are more vulnerable to the effects of sodium than others. If you're overweight, African-American, or a senior, chances are you're salt-sensitive, says Jeffrey Cutler, MD, senior scientific adviser for the National Heart, Lung, and Blood Institute. Since testing for salt sensitivity is complicated and unreliable, everyone should pay attention to her intake, says Kathy McManus, RD, director of nutrition at Brigham and Women's Hospital in Boston. The advice makes sense when you consider that nearly one in three Americans has high blood pressure, and 90 percent of us will eventually develop it if we continue eating and living the way we do now. A limited-salt has been linked to a healthier heart, and some research has linked it to fewer headaches, better cognitive function, and lower risk of painful stomach ulcers. And then there's bloat: Since salt makes you retain water, too much of it makes you look like you've packed on a few pounds. Who doesn't want to look leaner?

The 2001 DASH-Sodium (Dietary Approaches to Stop Hypertension) study tracked people with high blood pressure (140/90 or higher) and prehypertension (120/80 to 139/89). Researchers found that participants' blood pressure decreased when they reduced daily salt intake to 2,400 mg (the upper limit set by the National High Blood Pressure Education Program) or 1,500 mg (the amount your body needs every day). The biggest drop occurred in those who consumed the least sodium.