Keeping sodium intake low may prolong life according to a new study that set out to clarify the long-term risk of eating too much sodium and the benefits of cutting down.Based on following more than 3,000 people with elevated blood pressure for over 24 years, researchers found that risk of death from any cause rose in a straight line along with sodium intake.
"Our results are not that surprising because we know that sodium increases blood pressure, and we have found that it increases risk of cardiovascular disease also," said lead author Nancy R. Cook of Brigham and Women's Hospital and Harvard Medical School in Boston.
But some recent studies found a J-shaped curve, Cook told Reuters Health by email, indicating a higher rate of death among those consuming the lowest levels of sodium.
"We found a direct linear association, such that those with the lowest sodium levels had the lowest mortality rates," she said.
The researchers used data from two trials of hypertension prevention undertaken from 1987 to 1990 and 1990 to 1995. At the beginning of the trials, participants had blood pressure that was higher than is considered healthy but below the threshold for hypertension.
The trials assessed, among other things, the effects on blood pressure of reducing sodium in the diet and losing weight compared to making no changes in sodium intake, and followed participants for three to four years