A food-based dietary strategy lowers blood pressure in a low socio-economic setting: a randomised study in South Africa

Public Health Nutr. 2008 Dec;11(12):1397-406. doi: 10.1017/S136898000800342X. Epub 2008 Aug 27.


Objective: To assess the impact of a food-based intervention on blood pressure (BP) in free-living South African men and women aged 50-75 years, with drug-treated mild-to-moderate hypertension.

Methods: A double-blind controlled trial was undertaken in eighty drug-treated mild-to-moderate hypertensive subjects randomised to an intervention (n 40) or control (n 40) arm. The intervention was 8-week provision of six food items with a modified cation content (salt replacement (SOLO ), bread, margarine, stock cubes, soup mix and a flavour enhancer) and 500 ml of maas (fermented milk)/d. The control diet provided the same quantities of the targeted foods but of standard commercial composition and 500 ml/d of artificially sweetened cooldrink.

Findings: The intervention effect estimated as the contrast of the within-diet group changes in BP from baseline to post-intervention was a significant reduction of 6.2 mmHg (95 % CI 0.9, 11.4) for systolic BP. The largest intervention effect in 24 h BP was for wake systolic BP with a reduction of 5.1 mmHg (95 % CI 0.4, 9.9). For wake diastolic BP the reduction was 2.7 mmHg (95 % CI -0.2, 5.6).

Conclusions: Modification of the cation content of a limited number of commonly consumed foods lowers BP by a clinically significant magnitude in treated South African hypertensive patients of low socio-economic status. The magnitude of BP reduction provides motivation for a public health strategy that could be adopted through lobbying of the food industry by consumer and health agencies.

Publication types

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

MeSH terms

  • Aged
  • Antihypertensive Agents / therapeutic use
  • Blood Pressure / drug effects*
  • Blood Pressure / physiology
  • Diastole
  • Diet, Sodium-Restricted*
  • Double-Blind Method
  • Female
  • Health Behavior
  • Humans
  • Hypertension / diet therapy*
  • Hypertension / drug therapy
  • Male
  • Middle Aged
  • Social Class
  • Socioeconomic Factors
  • Sodium Chloride, Dietary / adverse effects*
  • Sodium Chloride, Dietary / pharmacology
  • Sodium, Dietary / adverse effects*
  • Sodium, Dietary / pharmacology
  • South Africa
  • Systole
  • Treatment Outcome


  • Antihypertensive Agents
  • Sodium Chloride, Dietary
  • Sodium, Dietary