For decades, experts have warned that too much salt in the diet can contribute to high blood pressure. A 25-year study recently published in the Journal of the American College of Cardiology offers more incentives for paying closer attention.

The American Heart Association estimates the average American’s daily salt consumption at 3,400 mg a day, a lot of it coming from processed food. The recommended daily limit for salt is 2,400 mg.

Researchers calculated that a person consuming 1.5 teaspoons of salt per day, which is the equivalent of 3,600 mg, might increase their odds of early death by 12% just by adding an additional half teaspoon. Subjects who consumed less than 1 teaspoon per day, about 2,300 mg of salt, had a 25% lower chance of premature death.