Conventional wisdom: Sodium consumption causes high blood pressure and heart disease, so we should eat less salt.
Contrarian view: Added sugars are more to blame for high blood pressure and heart disease, so we should reduce them instead of sodium.
High blood pressure, or hypertension, is the leading cause of America’s No. 1 killer of both women and men: heart disease. Studies have shown that reducing sodium can help control blood pressure, and since the late 1970s, the government and physicians have preached skipping the salt to cut our heart disease risk.
But surprisingly, reducing just sodium isn’t all that effective at dropping blood pressure. “Sodium intake is only one — and for most people not necessarily a large — factor in chronic hypertension,” says Hillel Cohen, co-executive editor of the American Journal of Hypertension and a clinical epidemiology and population health professor at the Albert Einstein College of Medicine. Most clinical trials show that cutting out 1,000 milligrams of sodium from a diet, a relatively large amount, results in only a small drop in blood pressure on average, Cohen says.
That’s partly because different people likely react to sodium in different ways. “There has long been consensus among hypertension specialists that some, but not all, people are ‘salt sensitive,’ ” Cohen says. So really, relatively few of us see meaningful blood pressure benefits from cutting salt.
We may even be going a little too far with our low-salt approach. Currently, the USDA’s Dietary Guidelines for Americans recommend consuming no more than 2,300 milligrams, or 1 teaspoon, of salt daily. The American Heart Association caps us at 1,500 milligrams daily. But a 2013 Institute of Medicine report found insufficient evidence to support restricting sodium consumption below 2,300 milligrams per day to prevent cardiovascular disease in the general population.
Instead, the focus should be on another white crystal. “When we think of heart disease and high blood pressure, the main dietary villain that we’ve been trained to think about is salt, when it’s actually sugar,” says James DiNicolantonio, a cardiovascular research scientist at St. Luke’s Mid America Heart Institute in Missouri and associate editor at the journal Open Heart. DiNicolantonio recently co-wrote a review of studies, published in the journal, about the effects of salt and sugar on high blood pressure and cardiovascular disease.
Added sugar, such as the kind that’s abundant in processed foods, isn’t a necessary nutrient like sodium. DiNicolantonio’s review points out that drinking sugar-sweetened beverages, one of the most popular added-sugar sources, ups blood pressure levels and is associated with an increased incidence of hypertension. More alarmingly, people who get at least 25 percent of their daily calories from added sugar — or 13 percent of the U.S. population — are almost three times as likely to die from cardiovascular disease than those who get just 10 percent of calories from the sweet stuff.
Cohen, who wasn’t involved with the review, explains that sugar and hypertension are likely linked, in large part, by excess calorie consumption and weight gain. After all, being overweight is a risk factor for high blood pressure. (The more you weigh, the more blood your tissues need to keep up oxygen and nutrient levels. The increase in blood volume tends to put more pressure on your vascular walls.) DiNicolantonio adds that excess sugar causes fluid retention, which also drives up blood volume and pressure, far more than excess salt.
So instead of obsessing over the saltshaker, it’s possible we’d improve our health more by cutting back on sweetened foods, with sugary drinks at the top of that list.