Take With a Grain of Salt
Should you keep your hands off that shaker? The health research is mixed
Pick your point of view: Salt is a poison that brings on high blood pressure, which in turn kills via heart attack and stroke. Or, salt is no big deal--it raises blood pressure in only some people, and for everyone else there's no reason to cut it from your diet.
As with many medical debates, there is no absolute answer, though the negatives about sodium--a key element of salt--are well known. It can boost blood pressure by causing people to retain water. The government now tells healthy adults to cap sodium consumption at 2,300 milligrams--well under the 4,000 or so Americans now take in on average.
But the logic isn't ironclad. No one really knows if salt causes the most common form of high blood pressure. Studies suggest that it's a culprit but also that it's aided and abetted by a lack of potassium and calcium, too much stress, and obesity. Research hasn't settled the issue because it's hard to count every grain that crosses people's lips, and you need a huge number of participants, tracked for many years, to statistically settle the question of whether excessive salt equals death. One recent review of nearly 30 trials found that cutting salt for at least a month reduced blood pressure by a small amount in people with high blood pressure and an even smaller amount in healthy people. That's in line with the results of most other studies, though a handful have shown no benefit at all to salt restriction.
The findings probably mask the fact that some people's genes and lifestyles mean their blood pressure will spike at the slightest whiff of soy sauce, while others can gulp the stuff without a budge in their numbers. Ditch diggers working in the sun all day probably need more salt than a petite office worker does, notes Michael Alderman, former president of the American Society of Hypertension. Self-experimentation with diet and regular blood pressure readings are the only ways to tell which category you fall into.
A pragmatic recommendation on salt restriction for those of us who aren't hypertensive comes from Charles Hennekens, an epidemiologist at Florida Atlantic University: "In my own view, the preponderance of evidence is that too much salt is harmful, or at least not helpful." In other words, to be safe it probably doesn't hurt to follow the government's advice.
But focusing the entire blood- pressure message on salt is misguided. It ignores, for example, a recent study showing that not only did cutting sodium help blood pressure regardless of diet but that the converse also held true. Eating a lower-fat diet rich in fruits, veggies, and low-fat dairy products also improved blood pressure, regardless of sodium levels.
Other routes. The point is that cutting salt is not the only route to lowering blood pressure. "We're trying to give people a palette of options," says William Vollmer, senior investigator at the Kaiser Permanente Center for Health Research and one of the study's authors. Most processed and fast foods aren't a big part of either a low-sodium or a generally healthy diet. The Center for Science in the Public Interest is focusing its anti-salt ire on processed and restaurant foods. Swanson's Hungry Man XXL roasted carved turkey dinner tops its hit list, with 5,410 milligrams of sodium. But desalinating the Hungry Man still leaves you with a meal containing 58 grams of fat and more than 1,400 calories. If you're concerned about your overall health and weight (and who isn't?), the best bet is to avoid most processed foods and instead focus on a broad, nutritious diet, including lean protein.