Significant health advantages will result from even a small reduction in sodium intake, which can be achieved by salting food less or not at all.
Another study confirmed that eating too much salt can be fatal.
The European Heart Journal study of 500,000 middle-aged Britons found that those who always added salt to their food had a 28% increased likelihood of dying before age 75.
Adding a little extra salt to a meal shortens life by two years for men and 1.5 years for women, research shows.
The study followed individuals for nine years and recorded those who died before 75. Researchers observed a relationship between salt and early death after accounting for other life-shortening variables and disorders.
People who ate the most fruits and vegetables had a little lower risk, but not statistically significantly.
At age 50, women who always added salt lost an average of 1.5 years of life, while men died 2 to 3 years sooner.
Three in 100 adults between 40 and 69 die prematurely in the general population.
One in 100 people in this age bracket would die prematurely from adding salt to diet, according to the study.
Our study is the first to link salt to early death. New research to support diet-health guidelines. Even a slight reduction in sodium intake, by adding less or no salt to food at the table, is likely to result in considerable health advantages, said Prof. Lu Qi from Tulane University School of Public Health and Tropical Medicine in New Orleans, USA.
A high-salt diet can raise blood pressure, raising the risk of heart attack or stroke. Adults should eat no more than 6 grammes of salt or 2.4 g of sodium per day, or about one teaspoon.
Researchers warn against reducing salt totally despite its adverse effects.
Given the signs that very low salt intake may be hazardous, it's vital to distinguish between individual recommendations and population-level initiatives, she added.
Prof. Annika Rosengren, a senior researcher and professor of medicine at the Sahlgrenska Academy of the University of Gothenburg in Sweden, said not adding extra salt to meals is probably not hazardous and could help lower the population's blood pressure