Sodium has been a necessary part of the diet since time began -- but based on how little the mainstream knows about it, you'd think it was discovered just last week.

Governments, health organizations and doctors are all pushing the completely unproven notion that a low-salt diet will prevent heart disease and improve health in people who already have the condition -- but the latest research shows they're wrong.

Dead wrong.

While it's true that too much salt can hurt you, odds are you're not getting even close to "too much." Too little salt, on the other hand, is every bit as dangerous -- and if you follow mainstream guidelines, you're already smack in the danger zone.

A new look at data on some 28,000 patients with either heart disease or a high risk of developing heart disease or diabetes found that people who consumed 4,000 mg per day actually had the lowest risk of heart disease.

Since most Americans get about 3,400 mg a day, that's actually well above the average intake -- and way above the guidelines, which call for a maximum of 2,300 mg of sodium a day for most people, and 1,500 mg a day for many others.

Stick to the lower intake, and you might want to make sure your affairs are in order: Those who only got between 2,000 mg and 3,000 mg a day actually had an 8.6-percent increase in the risk of dying from a heart-related condition, and a 5-percent boost in the risk of hospitalization for congestive heart failure than those who took in 4,000 mg a day.

Of course, that doesn't mean you should ignore your salt intake -- because the same study in the American Journal of Hypertension found that extremely high levels of salt are even worse.

How extreme? People who got between 7,000 mg and 8,000 mg of sodium a day had a 9.7-percent boost in the risk of dying of a heart-related event, and a 7-percent increase in the risk of a heart attack.

But here's the thing: It's almost impossible to get that much sodium from a diet of fresh foods, even if you add a dash of salt to everything.

Only packaged foods -- and lots of 'em -- can take you to that level. And in that case, is it really the salt -- or is it all the other junk used to make those meals?

My money's on the latter.

Salt isn't the only place the mainstream has gotten it backwards. Keep reading for the latest news on blood pressure.