Decreasing dietary sodium while following a self-selected potassium-rich diet reduces blood pressure.
Reducing dietary sodium reduces blood pressure (BP), a major risk factor for cardiovascular disease, but few studies have specifically examined the effect on BP of altering dietary sodium in the context of a high potassium diet. This randomized, crossover study compared BP values in volunteer subjects self-selecting food intake and consuming low levels of sodium (Na+; 50 mmol/d) with those consuming high levels of sodium (> or =120 mmol/d), in the context of a diet rich in potassium (K+). Sodium supplementation (NaSp) produced the difference in Na+ intake. Subjects (n = 108; 64 women, 44 men; 16 on antihypertensive therapy) had a mean age of 47.0 +/- 10.1 y. Subjects were given dietary advice to achieve a low sodium (LS) diet with high potassium intake (50 mmol Na+/d, >80 mmol K+/d) and were allocated to NaSp (120 mmol Na+/d) or placebo treatment for 4 wk before crossover. The LS diet decreased urinary Na+ from baseline, 138.7 +/- 5.3 mmol/d to 57.8 +/- 3.8 mmol/d (P < 0.001). The NaSp treatment returned urinary Na+ to baseline levels 142.4 +/- 3.7 mmol/d. Urinary K+ increased from baseline, 78.6 +/- 2.3 to 86.6 +/- 2.1 mmol/d with the LS diet and to 87.1 +/- 2.1 mmol/d with NaSp treatment (P < 0.001). The LS diet reduced home systolic blood pressure (SBP) by 2.5 +/- 0.8 mm Hg (P = 0.004), compared with the NaSp treatment. Hence, reducing Na+ intake from 140 to 60 mmol/d significantly decreased home SBP in subjects dwelling in a community setting who consumed a self-selected K+-rich diet, and this dietary modification could assist in lowering blood pressure in the general population.
Nowson
Caryl A
CA
Centre for Physical Activity and Nutrition Research, School of Health Sciences, Deakin University, Burwood Highway, Burwood, VIC 2125, Australia. nowson@deakin.edu.au
Morgan
Trefor O
TO
Gibbons
Carl
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000187:drug effects*; D018592:Cross-Over Studies; D004039:Diet, Sodium-Restricted; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017419:Potassium, Dietary / Q000008:administration & dosage*; D012727:Sex Characteristics; D013599:Systole
D017419:Potassium, Dietary