Research Questions Impact of Low-Sodium Diets on Heart Health

A European study has reportedly raised questions about the impact of
low-sodium diets on heart health, finding that people who apparently
consumed the least amount of salt did not lower their risk for high blood
pressure and, contrary to expectations, increased their risk of death from
cardiovascular disease (CVD). Katarzyna Stolarz-Skrzypek, et al., “Fatal and
Nonfatal Outcomes, Incidence of Hypertension, and Blood Pressure Changes
in Relation to Urinary Sodium Excretion,” Journal of the American Medical
Association, May 4, 2011. Researchers based their results on 24-hour sodium
excretion measurements taken over a median 7.9 years from 3,700 subjects
“randomly enrolled in the Flemish Study on Genes, Environment, and Health
Outcomes (1985-2004) or in the European Project on Genes in Hypertension
(1999-2001).” The findings from this cohort evidently indicated that while
higher sodium excretion aligned with an increase in systolic blood pressure,
“this association did not translate into a higher risk of hypertension or CVD
complications.” Moreover, according to the study abstract, “lower sodium
excretion was associated with higher CVD mortality.”

But some U.S. health experts have since criticized the study design and
warned that it should not be used to guide public policy. As Peter Briss, a
medical director at the Centers for Disease Control and Prevention, pointed out in a May 3 New York Times interview, the study subjects who excreted the least amount of salt also provided less urine than their counterparts and may
not have collected all of their urine in a 24-hour period. “At the moment, this
study might need to be taken with a grain of salt,” he was quoted as saying.