Jan Willem Elte, The Netherlands
Recently published results of a prospective crossover trial show that a low-salt diet for just a week provided a reduction in systolic blood pressure of about 6 mm as compared with those with a normal diet (daily intake approximately 4.5 gr) and 8 mm versus the group with high-sodium diet.
The trial involved 213 individuals, aged 50 – 75 years, with or without hypertension. A high-sodium regimen (approximately 2200 mg sodium added to usual diet) was compared with a low-sodium regimen (approximately 500 mg daily in total) both during one week. Average 24-hour ambulatory systolic and diastolic pressure and pulse pressure were measured. Among the 213 participants who completed both high- and low-sodium diet visits, the median age was 61 years, 65% were female and 64% black. The low-sodium diet lowered systolic blood pressure in nearly 75% of individuals compared with the high-sodium diet group.
So the effects obtained in one week were impressive and consistent in all subgroups (sex, age, race and BMI), including those with or without hypertension or those with antihypertensive medication. In diabetes patients (21 % of the study population) the reduction in blood pressure was even more impressive, close to 17 mm Hg. As mentioned before the results were similar with a first-line antihypertensive agent such as 12.5 mg hydrochlorothiazide. There were no excess adverse events.
Although these results are relatively easy to achieve with a rather small intervention it might be difficult for individuals to stick to the low-sodium diet in the long-term as the authors admit. At the very least, people with high BP should decrease their salt intake.
Sources:
- Gupta DK et al. Effect of dietary sodium on blood pressure. A crossover trial. JAMA.doi:10.1001/jama.2023.23651
- Hughes S. Low-salt diet cut BP by 6 mm Hg in 1 week: CARDIA-SSBP. Medscape Nov 15, 2023
