Two New Studies Address Salt Intake And Cardiovascular Disease

First study:

Fatal And Nonfatal Outcomes, Incidence Of Hypertension, And Blood Pressure Changes In Relation To Urinary Sodium Excretion, JAMA, May 2011

While an increase in sodium (as measured by sodium excretion) was associated with an increase in systolic blood pressure (but not diastolic blood pressure), "this association did not translate into a higher risk of hypertension or CVD complications."

Also, from news@JAMA which summarized the study:

"In the study, the researchers categorized the 3681 study participants according to sodium intake, using a procedure that measures sodium in the urine over a 24-hour period, considered the gold standard for such assessment. At a median of nearly 8 years later, participants in the group with the lowest sodium intake at the beginning of the trial were significantly more likely than the other 2 groups to die of cardiovascular disease."
- Author Insights: Questioning The Benefits Of Salt Restriction, JAMA News, May 3, 2011

Second study:

Reduced Dietary Salt For The Prevention of Cardiovascular Disease: A Meta-Analysis of Randomized Controlled Trials (Cochrane Review), American Journal of Hypertension, July 2011

Results:

“Relative risks (RRs) for all-cause mortality in normotensives and hypertensives showed no strong evidence of any effect of salt reduction CVD morbidity in people with normal BP.

Raised BP at baseline also showed no strong evidence of benefit.

Salt restriction increased the risk of all-cause mortality in those with heart failure.”

Neither of these studies lend strong support for the recommendation to restrict sodium ... for cardiovascular disease. However, other conditions may benefit from sodium restriction. High sodium intake has been associated with greater calcium losses and osteoporosis.¹ Also, the efficient renal mechanism that excretes excess sodium may not be fully effective if the kidney is compromised - as it is with diabetes, hypertension, or existing kidney and vascular disease.
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¹ Salt Intake, Hypertension, And Osteoporosis, Journal of Endocrinological Investigation, 2009