Feasibility of Low-Sodium, High-Potassium Processed Foods and Their Effect on Blood Pressure in Free-Living Japanese Men: A Randomized, Double-Blind Controlled Trial

• Published in: Nutrients 2021-10, Vol.13 (10), p.3497
• Main Authors: Umeki, Yoko, Hayabuchi, Hitomi, Adachi, Hisashi, Ohta, Masanori
• Format: Article
• Language: English
• Subjects: Antihypertensives; Blood pressure; Diet; Double-blind studies; Feasibility; Food processing; free-living settings; Glutamic acid; Hypertension; Intervention; poly-γ-Glutamic acid; Potassium; Pressure effects; Processed foods; Salt; Sodium; urinary Na/K ratio
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu13103497

We aimed to verify the effect of new low-sodium high-potassium seasonings and processed foods containing poly-γ-glutamic acid on blood pressure in free-living settings. To this end, we conducted a randomized, double-blind controlled trial on 187 Japanese men, aged 35–67 years, who did not use antihypertensives. Participants were randomly allocated to an intervention (n = 93) or a control group (n = 94). They were given a boxed lunch and miso soup (average Na and K content for the intervention group: 1175 and 1476 mg; for the control group: 2243 and 703 mg, respectively). Blood pressure was measured three times every morning for 1 week immediately before and during the final week of the trial. On the day before and the final day of the intervention period, 24 h urine samples were collected. After intervention, the intervention group showed a significantly stronger decrease in the urinary sodium-to-potassium ratio than the control group (p < 0.001). The mean difference in systolic blood pressure change after adjustment for baseline values between the two groups was −2.1 (95% CI: −3.6, −0.6) mmHg. Compliance between the groups was similar, suggesting successful blinding. In conclusion, the use of new seasonings and processed foods aimed at lowering blood pressure in free-living settings may be feasible and effective.