Taking Governments Advice with a Grain of Salt

WAPO picks up the salt wars: More scientists doubt salt is as bad for you as the government says

. . . There is one area of consensus: Both sides agree that eating too much salt, especially for people with high blood pressure, can be dangerous.

The critical disagreement concerns how to define “too much.”

Under the current dietary guidelines, too much is more than 2,300 milligrams of sodium per day - the amount of sodium in a teaspoon of salt. (For people over 50, and for African-Americans, the current recommended intake is even lower - 1,500 milligrams per day.)

If the U.S. salt warnings are correct, Americans are indeed endangering themselves on a massive scale. Americans typically go way over the limit, ingesting about 3,500 milligrams per day.

If the skeptics are correct, on the other hand, most Americans are fine. In their view, a typical healthy person can consume as much as 6,000 milligrams per day without significantly raising health risks. But consuming too little - somewhere below 3,000 milligrams - also raises health risks, they say.

To understand how divided scientists are on salt, consider that even authorities with the American Heart Association, one of the organizations promoting the current salt limits, don’t agree.

“The totality of the evidence strongly suggests that Americans should be lowering their sodium intake,” said Elliott Antman, the president of the American Heart Association. “Everyone agrees that current sodium intake is too high.”

This is the long-established view. It is based on the observation that, in some people, reducing salt consumption can lower blood pressure. Because high blood pressure is common and raises the risk of cardiovascular troubles, strict salt limits will benefit society, according to this view.

And bleeding some people, like those with haemochromatosis, can make them healthier. But it's hardly a good reason to call for the bleeding of the entire population.

None of this is persuasive to people like Suzanne Oparil, a former president of the American Heart Association.

For one thing, the blood-pressure reductions that come from abstaining from salt are relatively small on average, because individuals vary widely in their reactions. (An average person who reduces his or her salt intake from median levels to the U.S. recommended levels may see a drop in blood pressure from 120/80 to 118/79, according to American Heart Association figures.)

“The current [salt] guidelines are based on almost nothing,” said Oparil, a distinguished professor of medicine at the University of Alabama at Birmingham. “Some people really want to hang onto this belief system on salt. But they are ignoring the evidence.”

The evidence has always been weak, and suggest that a relatively small fraction of the of the population needs to reduce salt, and yet the guidelines have always been promulgated across the whole population. Why?

There are just some people who need to nag, and it's more fun to nag the whole world than just the folks that really need it.