According to a study by Cook et al published in the Journal of the American College of Cardiology keeping sodium intake low may prolong life.
The researchers conducted
two trials, phase I between1987 to 1990, over 18 months, and phase II
between1990 to 1995, over 36 months, both were undertaken in TOHP (Trials of
Hypertension Prevention), which implemented sodium reduction interventions. The
studies included multiple 24-h urine samples collected from pre-hypertensive
adults 30 to 54 years of age. Post-trial deaths were ascertained over a period
of 24 years.
After following 3,126 people with hypertension for
24 years, the investigators found an
increased mortality risk for those on high-sodium intake and a direct
relationship with total mortality, even at the lowest levels of sodium
intake. The 12% increase in total mortality per 1,000
mg of Na increased intake per 24 hours was impressive.
Most Americans consume
more salt than they need, according to the Dietary Guidelines published by the U.S. Department of Health and Human
Services and the U.S. Department of Agriculture. The guidelines recommend that sodium intake
should not exceed 2,300 milligrams of sodium a day, about a teaspoon of table
salt. The guidelines also recommend that
individuals with hypertension, blacks, and and older adults should limit sodium
intake to 1,500 mg per day.
The investigators concluded that their findings are suggestive that reduced
sodium intake may prolong life. a