Blood pressure change in a free-living population-based dietary modification study in Japan

J Hypertens. 2006 Mar;24(3):451-8. doi: 10.1097/01.hjh.0000209980.36359.16.


Objective: To assess whether dietary intervention in free-living healthy subjects is effective in improving blood pressure levels.

Design: Open randomised, controlled trial.

Setting: Free-living healthy subjects in two rural villages in north-eastern Japan.

Participants: Five hundred and fifty healthy volunteers aged 40-69 years.

Interventions: Tailored dietary education to encourage a decrease in sodium intake and an increase in the intake of vitamin C and carotene, and of fruit and vegetables.

Main outcome measures: Blood pressure, dietary intake and urinary excretion of sodium, dietary carotene and vitamin C, and fruit and vegetable intake data were collected at 1 year after the start of the intervention.

Results: During the first year, changes differed significantly between the intervention and control groups for dietary (P = 0.002) and urinary excretion (P < 0.001) of sodium and dietary vitamin C and carotene (P = 0.003). Systolic blood pressure decreased from 127.9 to 125.2 mmHg (2.7 mmHg decrease; 95% confidence interval, -4.6 to -0.8) in the intervention group, whereas it increased from 128.0 to 128.5 mmHg (0.5 increase; -1.3 to 2.3) in the control group. This change was statistically significant (P = 0.007). In contrast, the change in diastolic blood pressure did not significantly differ between the groups. In hypertensive subjects, a significant difference in systolic blood pressure reduction was seen between the groups (P = 0.032).

Conclusion: Moderate-intensity dietary counseling in free-living healthy subjects achieved significant dietary changes, which resulted in a significant decrease in systolic blood pressure.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Ascorbic Acid / administration & dosage
  • Blood Pressure*
  • Carotenoids / administration & dosage
  • Diet, Sodium-Restricted
  • Feeding Behavior*
  • Female
  • Fruit
  • Humans
  • Hypertension / prevention & control*
  • Hypertension / therapy
  • Japan
  • Life Style
  • Middle Aged
  • Sodium, Dietary / urine
  • Vegetables


  • Sodium, Dietary
  • Carotenoids
  • Ascorbic Acid