Humans, like many other animals, crave the taste of salt. Animals frequent salt licks, humans have traded salt for equal weights of gold, and the word “salary” comes from the Roman soldier’s allowance for purchasing salt. Salt appears in our language in idioms like “worth its salt” and “salt of the earth.” Shakespeare’s play King Lear is a variant of a folktale where a daughter tells her father she loves him as much as meat loves salt. In a murder mystery I read years ago, a character listed the four food groups as sweet, salty, sticky, and chocolate.
It’s no fair: everything that tastes good turns out to be bad for us. We love the taste of salt, but dietary guidelines tell us we should all limit our sodium intake to less than 2.3 grams (2300 mg) a day to avoid high blood pressure and death from cardiovascular disease. And those who are fifty-one, African American, or who have high blood pressure, chronic kidney disease or diabetes should limit their intake even further, to 1500 mg a day or less.
(Note: the salt molecule consists of an atom of sodium and an atom of chloride; 40% of the weight is sodium, so 1500 mg of sodium equals 3750 mg of salt, roughly ¾ of a teaspoon. Over 75% of our salt is already in the food, not added from the salt shaker.)
In 2010, the American Heart Association lowered its recommendations to 1500 mg a day for everyone. We thought that was good advice, but new evidence has muddied the waters.