America has a salt problem — and it's not high blood pressure. The Obama administration plans to set voluntary sodium targets for processed food makers this summer. Anti-salt campaigners believe that such measures will improve the nation’s health. They’re wrong, and the fixation on salt is diverting resources from strategies that would do more to improve health and save lives.
Health advocates say we eat too much sodium chloride (aka table salt), which puts us at risk of hypertension, stroke, and heart attack. Since around 75 percent of our sodium comes from processed foods, reducing sodium in those foods will result in less sodium consumed overall, reducing health risks. That’s the hope, anyway.
This might be a valid approach for the estimated 17 to 25 percent of the population who are “salt sensitive” — those whose blood pressure increases as a result of high salt consumption. But research indicates that salt isn’t the primary determining factor for hypertension even in this small subset of the population. Alcohol, fruit, and vegetable consumption, potassium intake, and weight are all just as important for hypertension, if not more so.
But let’s assume that this stealth sodium reduction scheme works and we all end up eating less salt. Would we be healthier? Only if dietary tinkering happens in a vacuum. But it doesn’t, and individuals might respond in a variety of unpredictable, unhealthy ways. For example, adding salt back into food at the table or eating fewer vegetables. Or, consumers and food processors might switch to salt alternatives, such as potassium chloride, which is safe for most people but not for the roughly 10 percent of the adult U.S. population with kidney disease. Any of these behavioral changes could put a portion of the population at higher risk for disease and death.
In fact, extremely low sodium diets — like very high sodium diets — correlate with a high risk of mortality, according to two 2014 studies. The higher death rates among low salt eaters may be related to factors in combination with or other than sodium, including an overall deficient diet. Whatever the underlying reasons, research indicates that people are less at risk when their diets contain between 2,700 mg and 6,000 mg of sodium a day. Incidentally, that’s close to what most Americans as well as most people on the planet already consume.
The amount of sodium that most people eat — between 2,600 mg and 4,800 mg a day — appears remarkably constant regardless of time, place, culture, or economic status. Those numbers come from researchers at the University of California, Davis who surveyed more than 50,000 people in 45 countries over the span of five decades, and they are higher than the government’s recommended maximum intake of 2,300 mg a day. Such data have prompted researchers at the Institute of Medicine to admit that there’s no evidence that consuming less than the recommended sodium maximum would benefit most people.
Public health advocates claim that even if their population-wide salt reduction efforts fail to result in health gains, they won’t do any harm. But new evidence suggests that this might not be true. In addition to the portion of the population that is “salt sensitive,” there seems to be a segment — around 11 to 16 percent — that has “inverse salt sensitivity.” For this group, restricting salt intake can have adverse consequences, including increased blood pressure. The majority of the population is “salt resistant;” they would not see a decrease in blood pressure from salt restriction. But research suggests that they — along with those who have inverse salt sensitivity — could experience worsening cholesterol and insulin levels as a result.
In any case, lifestyle changes other than extreme sodium reductions can be just as effective at lowering blood pressure, if not more so. For instance, 98 percent of American diets are deficient in potassium. A 2003 study found that increasing potassium by about 2,000 mg a day — roughly two and a half cups of cooked spinach of four bananas — reduces blood pressure almost as much as cutting sodium by 2,000 mg a day. In addition to increasing potassium, other lifestyle changes that have proved effective at reducing blood pressure include eating more fruits and vegetables, increasing fiber intake, and reducing alcohol — or, even better, a combination thereof.
Hypertension is a serious problem that puts millions of Americans at risk. But the evidence does not support an aggressive, population-wide campaign against salt. Because of this myopic focus on salt, valuable proposals for solving this complex disease have been ignored. Rather than a one-size-fits-all approach to health, we should instead educate people about their individual risk factors and options for prevention — including reducing consumption of salt and processed foods. Doing so would empower people to create diet plans tailored to their lifestyle and tastes.
If helping people is our goal, it’s time for a détente on the war on salt.
Originally posted at Real Clear Policy.