Reducing dietary salt may have a greater effect on older adults’ blood pressure than previously thought, according to a recent research meta-analysis.

While reducing salt intake also lowered blood pressure in almost all groups studied, the benefits were most pronounced in older adults, those with high blood pressure, and non-whites, reported lead author Polly Huang from The George Institute, Australia.

“[I]f you’re older and already have high blood pressure – and are therefore at greater risk of associated conditions such as stroke and heart disease – there is an even greater effect on blood pressure from the same amount of salt reduction,” she said.

The study also suggests that the longer one sticks to a low-salt diet, the longer this larger fall in blood pressure will continue. 

While some have questioned the need for eating less salt among people with normal blood pressure, taking this action may actually prevent or delay the high blood pressure onset that often comes with age, Huang added.

“The majority of the salt we eat is hidden in processed and packaged foods and most people aren’t aware that the amount they are consuming is raising their blood pressure and shortening their lives,” she said.

Dietary salt is a major culprit in high blood pressure, which in turn contributes to stroke and heart disease. The Dietary Guidelines for Americans recommends less than 2,300 mg of salt per day, according to the U.S. Food and Drug Administration. That’s equal to about one teaspoon.

The study was published online Tuesday in the BMJ.