Open Access Research

Feasibility and antihypertensive effect of replacing regular salt with mineral salt -rich in magnesium and potassium- in subjects with mildly elevated blood pressure

Essi S Sarkkinen12*, Mika J Kastarinen3, Tarja H Niskanen1, Pia H Karjalainen1, Taisa M Venäläinen12, Jay K Udani4 and Leo K Niskanen3

Author Affiliations

1 Oy Foodfiles Ltd, CRO in the field of nutrition, Neulaniementie 2 L 6, 70210 Kuopio, Finland

2 University of Eastern Finland, Institute of Public Health and Clinical Nutrition, Department of Clinical Nutrition, Food and Health Research Centre, Kuopio, Finland

3 Department of Medicine, Central Hospital Central Finland, Jyväskylä, Finland, and University of Eastern Finland, Faculty of Health Sciences, School of Medicine, Kuopio, Finland

4 Medicus Research LLC/UCLA School of Medicine, Northridge, California, USA

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Nutrition Journal 2011, 10:88  doi:10.1186/1475-2891-10-88

Published: 2 September 2011

Abstract

Background

High salt intake is linked to hypertension whereas a restriction of dietary salt lowers blood pressure (BP). Substituting potassium and/or magnesium salts for sodium chloride (NaCl) may enhance the feasibility of salt restriction and lower blood pressure beyond the sodium reduction alone. The aim of this study was to determine the feasibility and effect on blood pressure of replacing NaCl (Regular salt) with a novel mineral salt [50% sodium chloride and rich in potassium chloride (25%), magnesium ammonium potassium chloride, hydrate (25%)] (Smart Salt).

Methods

A randomized, double-blind, placebo-controlled study was conducted with an intervention period of 8-weeks in subjects (n = 45) with systolic (S)BP 130-159 mmHg and/or diastolic (D)BP 85-99 mmHg. During the intervention period, subjects consumed processed foods salted with either NaCl or Smart Salt. The primary endpoint was the change in SBP. Secondary endpoints were changes in DBP, daily urine excretion of sodium (24-h dU-Na), potassium (dU-K) and magnesium (dU-Mg).

Results

24-h dU-Na decreased significantly in the Smart Salt group (-29.8 mmol; p = 0.012) and remained unchanged in the control group: resulting in a 3.3 g difference in NaCl intake between the groups. Replacement of NaCl with Smart Salt resulted in a significant reduction in SBP over 8 weeks (-7.5 mmHg; p = 0.016). SBP increased (+3.8 mmHg, p = 0.072) slightly in the Regular salt group. The difference in the change of SBP between study groups was significant (p < 0.002).

Conclusions

The substitution of Smart Salt for Regular salt in subjects with high normal or mildly elevated BP resulted in a significant reduction in their daily sodium intake as well as a reduction in SBP.

Trial Registration

ISRCTN: ISRCTN01739816

Keywords:
blood pressure; hypertension; sodium reduction; mineral salt; low-sodium; high-potassium and high-magnesium salt